JP2007115784A - Exposure system, exposure method, and device manufacturing factory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lessen a burden related to control of information about a substrate. <P>SOLUTION: A wafer measuring instrument 400 measures information about a wafer W and writes that information, as prior measurement information, in an IC tag fixed to the wafer W through a writer/reader RW1 by radio communication, and reads in the prior measurement information from the IC tag fixed to the wafer W through a writer/reader RW2 after the wafer W is carried in an aligner 200. The aligner 200 performs processing related to exposure based on the prior measurement information thus read in. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exposure system, an exposure method, and a manufacturing factory for manufacturing the device used in a process for manufacturing a device such as a semiconductor element, a liquid crystal display element, an imaging element, and a thin film magnetic head.

  In a photolithography process, which is one of the semiconductor element manufacturing processes, exposure processing, development processing, and various types of wafer processing are repeatedly performed. The above exposure process uses an exposure apparatus to transfer a pattern formed on a mask or reticle (hereinafter referred to as a mask when collectively referred to) to a wafer (substrate) coated with a photosensitive agent such as a photoresist. The development process is a process for developing a photosensitive agent on the wafer after the exposure process to form a resist pattern on the wafer. The wafer processing is, for example, processing for etching a wafer into the shape of a resist pattern, processing for doping impurities into the wafer, processing for forming wiring on the wafer, and other processing.

  A single layer is formed on the wafer by performing the above exposure processing, development processing, and various types of wafer processing. In general, a semiconductor element is manufactured by repeatedly performing the exposure process, the development process, and various wafer processes several times to several tens of times while exchanging a plurality of masks, and overlapping a plurality of layers.

  By the way, in an exposure apparatus that performs an exposure process, in order to accurately superimpose a pattern (shot) that is to be exposed and formed on a pattern (shot) that is formed on a substrate in a previous process, the exposure apparatus is equipped with a stage apparatus. After the substrate is carried in, EGA measurement processing and other measurement processing are performed.

  However, in the exposure process, it is necessary to avoid a decrease in throughput, and in order to streamline and speed up such a measurement process, one of the measurement processes performed in the exposure apparatus before the substrate is carried into the stage apparatus. In some cases, a pre-measurement device that performs a part or all in advance is provided. In such a pre-measurement apparatus, in addition to the measurement process performed by the exposure apparatus as described above, there are various from the viewpoint of improving the exposure accuracy and throughput, or reducing the processing load of the control apparatus provided in the exposure apparatus. Pre-processing such as measurement processing and analysis processing based on the measurement result is performed. Note that such pre-processing such as analysis processing may be performed by an analysis device or the like provided separately from the pre-measurement device.

  The management of the pre-measurement information including the measurement result by the pre-measurement device and the analysis result by the pre-measurement device or the analysis device, etc. is performed by the upper management computer that generally manages the exposure system including the exposure device and the pre-measurement device This is performed by a host computer or the like that manages a plurality of production lines including the exposure system. That is, an exposure apparatus, a pre-measurement apparatus, an analysis apparatus, a management computer and a host computer (hereinafter, also referred to as a host computer) are connected via a network such as a LAN, and the pre-measurement information is transferred to the host computer, The host computer manages the board together with identification information for identifying the board from other boards. In the exposure apparatus, necessary data is obtained by reading the identification information set on a barcode or the like formed on the substrate and making an inquiry to the host computer.

  However, in the above-described conventional system, the host computer manages information such as pre-measurement information, and the number of boards to be managed may be enormous, and the host computer accompanying such information transmission / reception and information management There is a problem that the processing load of the network is large. In particular, in a relatively small-scale manufacturing system, it may be disadvantageous from the viewpoint of cost and the like to provide a high-level computer and manage it comprehensively, and such a small-scale system can easily cope with it. Is desirable.

  As a technique related to the present invention, as disclosed in Patent Document 1, a technique is disclosed in which identification information for identifying a substrate is set on a wireless non-contact identification tag on the surface of a wafer. . In this technology, the identification information is set in the tag instead of the bar code which has conventionally set the identification information of the board, and management of information such as the pre-measurement information needs to be performed by a host computer. Therefore, it does not solve the problems described above.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to reduce the burden associated with the management of information related to a substrate.
JP 2004-157765 A

  According to the present invention, an exposure apparatus that exposes and forms a pattern on a substrate placed on a substrate stage, and a pre-measurement of information related to the substrate before the substrate is placed on the substrate stage. In an exposure system comprising a measurement device, the wireless communication type information storage member attached to the substrate and the pre-measurement information measured by the pre-measurement device are attached to the substrate related to the pre-measurement. A writing device for writing to the information storage member by wireless communication, a reading device for reading the pre-measurement information by wireless communication from the information storage member attached to the substrate, and the exposure device provided with the reading An exposure system is provided that includes a processing device that performs processing related to exposure based on the content of the pre-measurement information read by the device.

  According to the present invention, information related to the substrate measured by the pre-measuring device is written to the information storage member attached to the substrate by wireless communication, and the information related to the substrate is read from the information storage member by wireless communication in the exposure apparatus. Therefore, it is not necessary to manage the information about the board by the host computer or the like together with the identification information. Accordingly, the burden of managing information on the substrate in the host computer is eliminated, and communication for managing information on the substrate between the host computer and the pre-measurement apparatus or the exposure apparatus can be eliminated. In addition, the information storage member, the writing device, and the reading device can be introduced at a lower cost than in the case of introducing a host computer that comprehensively manages the entire manufacturing system. Can also be easily introduced.

  According to the present invention, there is an effect that it is possible to reduce a burden associated with management of information related to a substrate. In addition, there is an effect that even a relatively small-scale manufacturing system can be introduced at a low cost.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Exposure system]
First, the overall configuration of the exposure system according to the present embodiment will be described with reference to FIG.

  The exposure system 100 is installed in a device manufacturing factory that processes a substrate such as a semiconductor wafer or a glass plate to manufacture an apparatus such as a micro device, and is adjacent to the exposure apparatus 200 including a laser light source and the like. And a wafer measuring instrument 400 as one of the pre-measuring devices disposed in the coating and developing apparatus 300. In the figure, for convenience of illustration, the exposure apparatus 200 and the coating and developing apparatus 300 display only one as a substrate processing apparatus in which these are integrated, but actually, a plurality of substrate processing apparatuses are provided. Yes. The substrate processing apparatus completes the coating process of applying a photosensitive agent such as a photoresist to the substrate, the exposure process of projecting and exposing a mask or reticle pattern image on the substrate coated with the photosensitive agent, and the exposure process. A developing process for developing the substrate is performed.

  In addition, the exposure system 100 includes an exposure process management controller 500 that centrally manages an exposure process performed by each exposure apparatus 200, an analysis system 600 that performs various arithmetic processes and analysis processes, an in-plant production management host system 700, and A reticle measuring instrument 800 as one of the pre-measuring devices is also provided. Among the apparatuses constituting the exposure system 100, at least the substrate processing apparatuses (200, 300) and the reticle measuring instrument 800 are installed in a clean room in which the temperature and humidity are controlled. In addition, each device is connected via a network such as a LAN (Local Area Network) installed in the device manufacturing factory or a dedicated line (wired or wireless) so that data communication can be performed appropriately between them. It has become.

  In each substrate processing apparatus, the exposure apparatus 200 and the coating and developing apparatus 300 are connected in-line to each other. The in-line connection here means connecting between apparatuses and between processing units in the apparatus via a transfer device that automatically transfers a substrate such as a robot arm or a slider. The wafer measuring instrument 400 is provided as one of a plurality of processing units arranged in the coating and developing apparatus 300, and various kinds of information relating to the substrate are loaded in advance before the substrate is loaded onto the wafer stage of the exposure apparatus 200. It is a device that measures. Reticle measuring instrument 800 is a device that measures information relating to the reticle in advance before carrying the reticle onto the reticle stage of exposure apparatus 100. The wafer measuring instrument 400 is exemplified here as being connected in-line in the track 300, but may be provided off-line. The reticle measuring instrument 800 may be either online or offline.

[Exposure equipment]
FIG. 2 shows a schematic configuration of the exposure apparatus 200. The exposure apparatus 200 is a step-and-scan projection exposure apparatus (scanning exposure apparatus), and includes an illumination optical system 12, a reticle stage RST that holds a reticle R, a projection optical system PL, and a wafer stage that holds a wafer W. WST and these control systems are provided. When the illumination optical system 12 outputs a control signal for instructing the emission of exposure light from the main controller 20, which will be described later, the illumination optical system 12 is substantially slit-shaped having a longitudinal direction in the direction (X direction) orthogonal to the scanning direction (Y direction). Illumination light IL having a uniform illuminance is emitted to illuminate reticle R. As the illumination light IL, for example, g-line (wavelength 436 nm), i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), or the like is used.

  Reticle stage RST is arranged on reticle base board 13, and reticle R is fixed to the upper surface thereof by vacuum suction. Reticle stage RST is moved in the X and Y directions and in the rotational direction within a plane perpendicular to optical axis AX of projection optical system PL (in the XY plane) by a reticle stage drive unit (not shown) including a linear motor, a voice coil motor, and the like. It can be driven minutely and can be driven at a scanning speed specified in the scanning direction. The side surface of the reticle stage RST is mirror-finished to serve as a reflection surface that reflects the laser beam from the reticle interferometer 16. The reticle interferometer 16 detects the position of the reticle stage RST based on the interference light obtained by causing the reflected light from the reflecting surface to interfere with the predetermined reference light. Position information of reticle stage RST from reticle interferometer 16 is sent to stage control device 19 and main control device 20 via this, and stage control device 19 responds to an instruction from main control device 20 in a reticle stage. Based on the position information of RST, reticle stage RST is driven via a reticle stage drive unit (not shown).

  Projection optical system PL is arranged below reticle stage RST, and the projection magnification thereof is set to 1/5 or 1/4, for example. When the illumination area IAR of the reticle R is illuminated by the illumination light IL from the illumination optical system 12, the circuit pattern of the reticle R in the illumination area IAR is reduced by the illumination light IL that has passed through the reticle R via the projection optical system PL. An image (partial inverted image) is formed on wafer W held on wafer stage WST.

  Wafer stage WST is disposed on wafer base board 17 and includes wafer holder 18 that holds wafer W by vacuum suction. The wafer holder 18 can be tilted in an arbitrary direction with respect to the best imaging plane of the projection optical system PL by a driving unit (not shown), and can be finely moved in the optical axis AX direction (Z-axis direction) of the projection optical system PL. It is configured to be capable of rotating around its axis. Wafer stage WST can be moved stepwise in the two-dimensional directions of the X axis and the Y axis by wafer drive device 15 and is also scanned and moved in the Y direction. The position of wafer stage WST is measured in the same manner as in reticle interference system 16 described above, by irradiating laser light onto the mirror-finished side surface of wafer stage WST from wafer interferometer 24. Near the center of the wafer holder 18, a center table (not shown) is provided for carrying the wafer W in and out so that the wafer W can be sucked and held and moved up and down.

  The measurement values on each measurement axis of the wafer interferometer 24 are sent to the stage controller 19 and the main controller 20 via the stage controller 19, and the stage controller 19 responds to an instruction from the main controller 20 with the wafer stage WST. Control the position of the. A reference mark plate FM is provided on wafer stage WST, and the relative position relationship between the position of a detection center of an alignment system ALG (to be described later) and the position of a projected image of a reticle pattern is provided on the surface of reference mark plate FM, for example. Baseline measurement reference marks and other reference marks for measuring the above are formed.

  An off-axis alignment system ALG for detecting the position of an alignment mark (wafer mark) attached to each shot area on the wafer W is provided on the side of the projection optical system PL. As the alignment system ALG, for example, an FIA (Field Image Alignment) type alignment sensor as disclosed in JP-A-2-54103 is used. This alignment system ALG is light in a wavelength region that does not sensitize the photoresist applied on the wafer W, and irradiates the wafer with illumination light (for example, white light) having a predetermined wavelength width (for example, about 500 to 800 nm). Then, an image of the alignment mark on the wafer W and an image of the index mark on the index plate arranged in a plane conjugate with the wafer W are formed on the light receiving surface of an image sensor (CCD camera or the like). It is to detect. The alignment system ALG supplies the imaging result of the alignment mark (or the reference mark on the reference mark plate FM) to the main controller 20.

  An irradiation optical system AF1 for supplying an imaging light beam (detection beam FB) for forming a plurality of slit images toward the best imaging surface of the projection optical system PL from an oblique direction with respect to the optical axis AX direction; An oblique incidence type multi-point focal position detection system AF having a light receiving optical system AF2 that receives each reflected light beam of the imaging light beam on the surface of the wafer W through a slit is provided. The multi-point focus position detection system AF measures the position of the wafer W in the Z direction and the tilt with respect to the Z axis, and controls the position and tilt of the wafer holder 18 in the Z direction via the main controller 20 and the stage controller 19. Is done.

  The exposure apparatus 200 also includes a wafer pre-alignment apparatus 32 disposed at the wafer load position. The wafer pre-alignment device 32 is provided below the main body 34, the main body 34, and a vertical movement / rotation mechanism 38 that can suspend and support the wafer carry-in arm 36 and can be moved up and down, and above the carry-in arm 36. Three measuring units 40a, 40b, and 40c are provided. Although not shown in detail, the measurement units 40a to 40c are configured to include a light source, a collimator lens, a diffusion plate, a half mirror, a mirror, an imaging optical system, and an imaging device. Inside the main body 34 are incorporated control devices including a signal processing system for processing signals sent from the measurement units 40a, 40b, and 40c, a control system for the vertical movement / rotation mechanism 38, and the like.

  The wafer pre-alignment device 32 is controlled by the stage control device 19 based on an instruction from the main control device 20, and when the position of the notch of the wafer W is set to the 6 o'clock position in FIG. The imaging field of view of the two measuring units 40a, 40b, and 40c is set to the positions VA, VB, and VC in FIG. 3A, and the notch position is set to the 3 o'clock position in FIG. The imaging field of view is set at positions VC, VD, and VE in FIG. The outer edge (outer shape) of the wafer W is detected in each imaging field, the imaging signals from the measurement units 40a, 40b, and 40c are processed by the control device built in the main body 34, and stage control is performed based on the signals from the control device. The apparatus 19 determines the errors X and Y of the center position of the wafer W and the rotation error θz. In addition, in order to correspond to each of the positions of the notches described above, five measurement units may be installed corresponding to each of the imaging fields of view VA to VE, and the wafer W is rotated with respect to the three measurement units. It may be possible to cope with this. For a wafer provided with an orientation flat (hereinafter referred to as an orientation flat), the imaging field of view of the measurement unit is set as shown in FIG.

  Of the errors obtained by the wafer pre-alignment apparatus 32 based on the outer shape measurement of the wafer W, the rotation error θz is corrected by rotating the wafer by the rotation mechanism 38 of the loading arm 36, and the position errors X and Y are The position error is sent to the main control device 20 via the stage control device 19, and when the wafer W is loaded (loaded) into the wafer holder 18 based on an instruction from the main control device 20 by the stage control device 19. Correction is performed by minutely driving wafer stage WST by X and Y. The position errors X and Y may be corrected by adding them as offsets to the movement amount of wafer stage WST during search alignment described later.

  The carry-in arm 36 includes a horizontal member horizontally attached to the lower end of the drive shaft driven by the vertical movement / rotation mechanism 38, and three L-shaped hook portions projecting downward from the end of the horizontal member. And have. The loading arm 36 is configured so that the wafer W can be loaded into the space formed by the horizontal member and the L-shaped hook from the −Y direction by a wafer transfer arm 52 (FIG. 4) described later. Further, the carry-in arm 36 can move the wafer W up and down while driving the vertical movement / rotation mechanism 38 to suck and hold the back surface of the wafer W through the suction hole of the hook portion.

  In FIG. 4, the wafer transfer arm 52 is provided with a load arm and an unload arm individually on the upper and lower sides, and each is driven with a predetermined stroke along the Y-axis direction by the arm drive mechanism 53. Yes. The arm drive mechanism 53 includes a linear guide that extends in the Y-axis direction and a slide mechanism that reciprocates in the Y-axis direction along the linear guide. When the wafer W is transferred from the load arm of the wafer transfer arm 52 to the loading arm 36, the loading of the wafer W is performed by moving the loading arm 36 up and down. When the exposed wafer W on the wafer stage WST is unloaded, the wafer W is received from the center table to the unload arm of the transfer arm 52 by the vertical movement of the center table (not shown) on the wafer stage WST. It is supposed to be passed. These drive mechanisms are controlled by the stage controller 19 shown in FIG.

  In FIG. 2, the main controller 20 includes a so-called microcomputer (or workstation) comprising a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory) and the like. Then, the exposure apparatus 200 is controlled as a whole. For example, an input device such as a keyboard (not shown) and a display device (not shown) such as a CRT display (or liquid crystal display) are connected to the main controller 20. The main controller 20 is connected to a storage device 21 for storing device parameters and the like. It is assumed that a program executed by the CPU of the main control device 20 is installed in the storage device 21.

[Coating and developing equipment]
Next, the track 300 provided in each substrate processing apparatus will be described with reference to FIG. The track 300 is installed in a chamber surrounding the exposure apparatus 200 so as to be connectable to the exposure apparatus 200 in an in-line manner. In the track 300, a transfer line 301 for transferring the wafer W is arranged so as to cross the central portion thereof. One end of the transfer line 301 is a wafer carrier 302 that stores a number of wafers W that have been unexposed or processed by the substrate processing apparatus in the previous process, and a number of wafers W that have completed the exposure process and the development process in the substrate processing apparatus. A wafer carrier 303 is disposed, and a conveyance port (not shown) with a shutter on the side surface of the chamber of the exposure apparatus 200 is installed at the other end of the conveyance line 301.

Further, a coater part (application part) 310 is provided along one side of the conveyance line 301 provided in the track 300, and a developer part (developing part) 320 is provided along the other side. The coater unit 310 includes a resist coater 311 for applying a photoresist to the wafer W, a pre-baking device 312 including a hot plate for pre-baking the photoresist on the wafer W, and cooling for cooling the pre-baked wafer W. A device 313 is included.

The developer unit 320 bakes the photoresist on the wafer W after the exposure processing, that is, a post-bake device 321 for performing so-called PEB (Post-Exeposure Bake), PEB.
The apparatus includes a cooling device 322 for cooling the wafer W subjected to the above and a developing device 323 for developing the photoresist on the wafer W. Further, before the wafer W is transferred to the exposure apparatus 200, a wafer measuring instrument 400 is installed in-line as an in-line measuring instrument for measuring information related to the wafer W in advance. Details of the wafer measuring instrument 400 will be described later.

  4, each unit (resist coater 311, pre-bake device 312, cooling device 313) constituting the coater unit 310, and each unit (post-bake device 321, cooling device 322, developing device) constituting the developer unit 320. 323), and the configuration and arrangement of the in-line measuring instrument 400 are merely examples, and in reality, a plurality of other processing units, buffer units, and the like are further provided, and each unit is arranged spatially, and between each unit. In addition, a robot arm, an elevator and the like for transferring the wafer W are also provided. In addition, the processing order is not always the same, and the route through which the wafer W is processed between the units depends on the processing contents of the processing unit and the overall processing time. Optimized from a viewpoint and may change dynamically.

  The main controller 20, the coater unit 310 and the developer unit 320, the wafer measuring instrument 400, and the analysis system 600 included in the exposure apparatus 200 are connected by wire or wirelessly as described above, and each process start or process end is performed. The indicated signal is transmitted and received. In the exposure apparatus 200, a table 51 is disposed so as to extend substantially along the extended line of the central axis of the transfer line 301 provided in the track 300, and a wafer transfer arm for transferring the wafer W to the transfer arm 36 on the + Y side thereof. 52 etc. are arranged. Further, on the −X side of the table 51, a transfer robot 54 that can hold and transfer the wafer W at the tip thereof is installed. In addition, sensors for measuring the temperature, humidity, and pressure inside the chamber of the exposure apparatus 200 and the temperature, humidity, and pressure outside the substrate processing apparatus are installed, and detection signals from these sensors are sent to the main controller 20. Supplied and recorded in the storage device 21 for a certain period of time.

[Reticle measuring instrument]
The reticle measuring instrument 800 is a device that measures information related to the reticle R in advance, and at least one is provided corresponding to the type of information related to the reticle to be measured. Examples of the reticle measuring instrument 800 include a measuring device that measures the surface shape (flatness) of the reticle, an inspection device that inspects foreign matter and pattern defects attached to the surface of the reticle R, and a pattern drawing error formed on the reticle R. A measuring device or the like that measures the above is exemplified. In order to flexibly respond to the measurement item, the state of the wafer, the resolution, etc., it is desirable to provide a plurality of types of reticle measuring instrument 800 so that it can be selected and used according to the situation. In addition to the above-described sensor, reticle measuring instrument 800 includes a measurement control device for processing measured data. Here, it is assumed that reticle measuring instrument 800 is provided in-line in the reticle transport apparatus that transports reticle R to reticle stage RST, but it may be provided offline.

(1) Reticle surface shape measuring device As an example of the reticle measuring device, a reticle measuring device for measuring the surface shape of the reticle R will be described. As shown in FIG. 5, reticle measuring instrument 800 includes reticle stage RST ′ corresponding to reticle stage RST in exposure apparatus 200, reticle holder RH ′ that is a holder of the same type as the reticle holder, and Fizeau interferometer 60. And. Reticle measuring instrument 800 is installed in a transport path by a reticle transport system (not shown) that transports reticle R of exposure system 100. In the exposure system 100, for example, before the reticle R is carried into the exposure apparatus 200 under the control of the exposure process management controller 500, the reticle R is carried into the reticle measuring instrument 800 by a reticle conveyance system (not shown), and the reticle holder. Vacuum suction is held at an appropriate vacuum pressure on RH ′. The reticle measuring instrument 800 measures the surface shape of the pattern surface of the reticle R in a state of being held by suction on the reticle holder RH ′.

  At this time, the reticle R is held such that the pattern surface faces the −Z side. In order to enable measurement of the surface shape of the pattern surface of the reticle R, in the reticle measuring instrument 800, on the −Z side of the reticle holder RH ′, that is, on the pattern surface side of the reticle R held on the reticle holder RH ′. A Fizeau interferometer 60 is provided. The Fizeau interferometer 60 includes a laser light source 61, a lens 62, a diaphragm 63, a beam splitter 64, a λ / 4 wavelength plate 65, a collimator lens 66, reference surface members 67 and 68 on which reference surfaces 67A and 68A are formed, and a lens 69. The interference fringe detection unit 70 and the processing device 71 are included.

  As shown in FIG. 5, for example, light emitted from a laser light source 61 such as a He—Ne laser having an oscillation wavelength of 633 nm is coherent and has linear polarization direction (X-axis direction) parallel to the paper surface. Is set to be a luminous flux of. This light beam passes through a lens 62 and a diaphragm 63 for removing stray light and the like and then enters a beam splitter 64. The beam splitter 64 transmits a linearly polarized light beam having a polarization direction in the X-axis direction. The transmitted light beam enters the λ / 4 wavelength plate 65, is converted into circularly polarized light, is converted into parallel light by the collimator lens 66, and then enters the reference surface member 67. On the reference surface 67A formed on the reference surface member 67, the parallel light is partially reflected and the rest is transmitted. The transmitted light beam is irradiated on the entire pattern surface of the reticle R held by the reticle holder RH ′. For example, when the entire pattern surface of the reticle R is chrome-deposited, the irradiated parallel light is irradiated with the pattern. Reflect on the surface.

  The light reflected by the reference surface 67A of the reference surface member 67 (reference light) and the light reflected by the pattern surface of the reticle R (measurement light) are polarized in the Y-axis direction by the λ / 4 wavelength plate 65. Is reflected by the beam splitter 64 while being condensed through the collimator lens 66. The light beam reflected by the beam splitter 64 is converted into parallel light by the lens 69 and guided to an interference fringe detection unit 70 formed of a CCD (Charge Coupled Device). On the light receiving surface of the interference fringe detection unit 70, interference fringes of light reflected and synthesized from both of the reference surfaces 67A of the reference surface member 67 and the pattern surface of the reticle R are formed. The interference fringes are detected by the detection unit 70.

  That is, if the distance between the reference surface 67A of the reference surface member 67 and the pattern surface of the reticle R is d, the reference light and the measurement light interfere with a 2d optical path difference in one reciprocation, and the optical path difference is a laser. When it is an odd multiple of 1/2 of the wavelength, they cancel each other to produce a dark line, and when the optical path difference is an integral multiple of the laser wavelength, they strengthen each other to produce a bright line, resulting in an interference fringe detector. Interference fringes are formed on the light receiving surface 70.

  The detection result of the interference fringes is sent to the processing device 71. The processing device 71 calculates the surface shape of the pattern surface of the reticle R held by the reticle holder RH ′ based on the detection result of the interference fringes. Specifically, the processing device 71 cumulatively calculates the number of bright lines and dark lines of the interference fringes based on the detection result of the interference fringes, so that the pattern surface of the reticle R according to the distribution state of the interference fringes is calculated. “Surface shape data” corresponding to the gradient is provisionally determined. Then, along with the accumulation calculation, the constant gradient and the constant defocus (offset component) included in the temporarily determined surface shape data are removed as accumulated errors inherent in the surface shape data, and the final reticle R Surface shape data is calculated. The surface shape data is calculated as digital data such as surface height (Z position) data with respect to a certain in-plane position (XY position), for example.

  On the other hand, when reticle R is a transmissive reticle whose pattern surface is not subjected to chromium deposition, a part of the light beam irradiated on the entire pattern surface of reticle R is reflected by the pattern region, but the remaining light beam Reaches the surface opposite to the pattern surface of the reticle R, and a part of the surface is reflected and the rest is transmitted. The light beam transmitted through the reticle R reaches the reference surface 68A of another reference surface member 68. The reference surface 68A is a surface having a high reflectance, and the light beam is reflected by this surface and returns to the reticle R. Then, in the same optical path as described above, the reference light reflected from the reference surfaces 67A and 68A of the reference surface members 67 and 68 and the pattern surface of the reticle R are reflected, or the opposite surface is reflected. The interference fringe with the measured light is detected by the interference fringe detector 70.

  As described above, in the reticle measuring instrument 800, when the reticle having the entire surface of which the chromium is vapor-deposited is held by the reticle holder RH ′, the reference light reflected by the reference surface 67A of the reference surface member 67 Interference fringes with the measurement light reflected by the pattern surface are observed by the interference fringe detector 70. When the transmission reticle as the reticle R is held by the reticle holder RH ′, the reference plane member 68 Interference fringes between the reference light reflected by the reference surface 68A and the measurement light reflected by the pattern surface and the back surface thereof are observed. Thereby, in the reticle measuring instrument 800, the entire surface of the pattern surface, whether a chrome-deposited reticle, a transmissive reticle, or a reticle having a circuit pattern formed in its pattern region, is used. The shape can be measured. Here, the measurement of the reticle flatness does not have to be performed on the entire pattern surface. Based on the reticle pattern design data, a plurality of transmission or reflection portions of the reticle surface are uniformly distributed at a predetermined pitch in the X-axis direction and the Y-axis direction. You may obtain approximately from the measurement points. For example, the reticle flatness is approximately obtained from the measurement values at the measurement points of 35 points in the reticle plane, with 7 points in the Y-axis direction (scan direction) and 5 points in the X-axis direction.

  The reticle stage RST 'is provided with a mark plate corresponding to the reticle mark plate, similarly to the reticle stage RST. When measuring the surface shape of the pattern surface of the reticle R held by the reticle holder RH 'by the Fizeau interferometer 60, the surface shape of the mark plate is also measured. That is, according to the measurement result of the reticle measuring instrument 800, the surface shape data of the pattern surface of the reticle R based on the surface position of the mark plate is obtained. In the reticle measuring instrument 800, the Fizeau interferometer 60 can be improved in detection accuracy by using a double-pass interferometer in which the laser beam passes through the subject twice.

(2) Reticle foreign matter and pattern defect measuring instrument As another example of the reticle measuring instrument, see FIG. 6 for a measuring instrument that detects foreign matter adhering to the surface of the reticle R and detects defects in the pattern formed on the reticle R. The reticle measuring instrument 800 described below includes a light source 801, a vibrating mirror 802, a scanning lens 803, and light receivers 808, 809, and 810. In addition, it is assumed that a circuit pattern is formed on the pattern surface (test surface 804) of the reticle R, and a foreign substance 806 is attached to a part of the circuit pattern.

  The light beam L1 emitted from the light source 801 is deflected by a vibrating mirror (galvano scanner mirror or polygon scanner mirror) 802 and enters the scanning lens 803, and the light beam L2 emitted from the scanning lens 803 is detected. A scan line 805 on the surface 804 is scanned. At this time, if the test surface 804 is moved in a direction perpendicular to the scanning line 805 at a speed slower than the scanning cycle of the light beam L2, the entire surface of the test surface 804 can be scanned by the light beam L2. . In this case, the scattered light L3 is generated when the light beam L2 is irradiated on the region where the foreign substance 806 exists on the surface of the test surface 804. Further, there is a periodic structure (hereinafter, collectively referred to as a pattern) 807 such as a circuit pattern on the reticle R, a circuit pattern on the wafer W, or the like, which is different from the foreign matter or pattern defect adhering to the test surface 804. When the region is irradiated with the light beam L2, diffracted light L4 is generated from the pattern 807.

  In FIG. 6, the light receivers 808, 809, and 810 are disposed so as to face the scanning line 805 from different directions. The scattered light L3 generated from the foreign material 806 is isotropically scattered light generated in almost all directions, whereas the diffracted light L4 generated from the pattern 807 is generated by diffraction and thus is spatially discrete. The light is emitted into the light (light with strong directivity). When light is detected by all of the light receivers 808, 809, and 810 using the difference in properties between the scattered light L3 and the diffracted light L4, the light is scattered light from the defect. , 809 and 810, it is determined that the light is diffracted light from the pattern. Thereby, the pattern 807 and the foreign material 806 can be distinguished and detected.

[Wafer measuring instrument]
The wafer measuring device 400 is an apparatus that pre-measures information related to the wafer W, and at least one is provided corresponding to the type of information related to the wafer to be measured. For example, sensors for measuring marks (patterns) formed on a wafer, alignment marks and other marks formed on a wafer, sensors for measuring line width, shape, and defects of a pattern, wafer surface shape (flatness) ), A focus sensor, and the like. In order to respond flexibly according to measurement items, wafer status, resolution, etc., it is desirable to provide a plurality of sensors so that they can be selected and used according to the situation. Although the wafer measuring instrument 400 as an inline measuring instrument provided inline in the coating and developing apparatus will be described here, the wafer measuring instrument 400 may be provided offline.

(1) Alignment Mark / Edge Measuring Device As an example of a wafer measuring device, an alignment mark (search mark, fine mark) formed on the wafer W and a measuring device for measuring the edge of the wafer W are shown in FIGS. The description will be given with reference. The wafer measuring instrument 400 includes a stage device IST that can move in the XY plane, a sensor 410, a stage driving device 415, a background plate 420, a laser interferometer system 424, and a pre-measurement control device 450. Has been.

  The stage apparatus IST includes an XY stage and a Z stage, and the position and posture of the stage apparatus IST can be adjusted in the XY plane direction, the Z-axis direction, and the tilt direction with respect to the XY plane by the stage driving device 415. Further, a laser interferometer system 424 for measuring the position of the stage apparatus IST in each direction is provided. This laser interferometer system 424 has the same configuration as the wafer laser interferometer 24 of the exposure apparatus 200, and can measure at least the XY plane position of the stage apparatus IST. A turntable TT that is rotatable about its rotation axis is provided at the center of the stage apparatus IST, and the wafer W can be sucked and held on the turntable TT. A disk-shaped background plate 420 having a diameter larger than that of the wafer W is installed on the upper surface of the stage apparatus IST. When the wafer W placed on the turntable TT is viewed from above, the background plate 420 covers the entire edge of the wafer W.

  The sensor 410 is a sensor that can detect both the edge of the wafer W and the position of the alignment mark formed on the wafer W. The sensor 410 has basically the same configuration as the alignment system ALG provided in the exposure apparatus 200. Can be used. That is, the sensor 410 is an imaging type sensor that illuminates a detection target by a falling-down illumination method and images the detection target by reflected light of the illumination. The sensor 410 employs an optical zooming system, and detects when detecting the edge of the wafer W, when detecting a search mark on the wafer W, and when detecting a fine mark. The imaging magnification can be changed according to the object.

  Based on the detection result of the sensor 410 and the position information of the stage device IST detected by the laser interferometer system 424 at the time of detection, the preliminary measurement control device 450 determines the outer shape of the wafer W and the search mark on the wafer W. In addition, the position coordinates of the fine mark can be measured. The wafer measuring device 400 performs pre-measurement on the wafer W before being carried into the exposure apparatus 200 with the above-described configuration. The pre-measurement result in the wafer measuring instrument 400 is written into an IC tag attached to the wafer W via a writing / reading device described later, and sent to the main controller 20 of the exposure apparatus 200.

  Note that the pre-measurement process by the wafer measuring instrument 400 can be performed after the mark formation on the front layer of the wafer W is completed, but preferably after the wafer W is loaded into the track 300, preferably after resist application. And before carrying in the exposure apparatus 200, that is, before the pre-alignment process in the exposure apparatus 200. Note that the installation location of the wafer measuring instrument 400 is not limited to that of the present embodiment. For example, in addition to the inside of the track 300, it may be in the chamber of the exposure apparatus 200, or an apparatus dedicated to measurement independent of these apparatuses. It may be provided and connected by a transfer device. However, when the wafer measuring instrument 400 is installed in the track 300, there is an advantage that the dimension and shape of the exposure resist pattern can be measured immediately.

(2) Wafer Surface Shape Measuring Device Next, as another example of a wafer measuring device, a measuring device that pre-measures information (surface shape) on the flatness of the wafer W will be described with reference to FIG. Wafer measuring instrument 400 includes wafer stage WST ′, wafer holder WH ′, and Fizeau interferometer 60 ′. Wafer stage WST ′ is a stage that is substantially the same type as wafer stage WST, but may be a fixed stage that is not movable. Wafer holder WH ′ is a holder of the same type as wafer holder WH, and holds wafer W by vacuum suction (that is, in the same manner as wafer holder WH of exposure apparatus 200).

  In this wafer measuring instrument 400, as with the reticle measuring instrument 800, the surface shape of the wafer W while being sucked and held by the wafer holder WH ′ is measured using the Fizeau interferometer 60 ′. The Fizeau interferometer 60 ′ can have the same configuration as that of the Fizeau interferometer 60 except that it does not include the reference surface member 68. Therefore, detailed description of the configuration is omitted. That is, the Fizeau interferometer 60 'is a reflection measurement type interferometer.

  Wafer stage WST 'is provided with a mark plate corresponding to reference mark plate FM, as with wafer stage WST. Since the surface of the mark plate is strictly defined as a substantially flat surface, the signal corresponding to the surface shape of the mark plate is a signal indicating the height of the mark plate. Therefore, if the signal corresponding to the surface shape of the mark plate is compared with the signal corresponding to the surface shape of the wafer W, the relative height between the surface of the mark plate and the height of the measurement target surface of the surface shape of the wafer W The clear relationship becomes clear and the difference between them can be obtained. That is, the surface shape of the wafer W held by the wafer holder WH ′ can be measured by the Fizeau interferometer 60 ′ using the surface of the mark plate as a reference.

[Advance Information Communication System]
Pre-measurement information measured by wafer measuring instrument 400 and reticle measuring instrument 800 as a pre-measuring device (if any processing is performed based on the measurement information by wafer measuring instrument 400 or reticle measuring instrument 800, the processing result The exposure apparatus 200 via a prior information communication system including an IC tag attached to the wafer W and a writing / reading device for writing and / or reading information to and from the IC tag by wireless communication. To the main controller 20. Note that some or all of the processing performed by wafer measuring instrument 400 or reticle measuring instrument 800 (processing other than measurement processing, such as calculation, evaluation, and determination) may be performed by analysis system 600. The processing result of the processing performed in is also referred to as pre-measurement information.

  In order to realize this prior information communication system, an IC tag is attached to the end of the wafer W. An IC tag is a tag (tag) equipped with an ultra-small IC chip and an antenna, and can store and hold various types of information, and the information can be contacted with a writing / reading device (reader / writer) through the antenna. Can read and write information. There are two types of IC tags: a type that does not have a battery, receives a radio wave emitted from a writing / reading device, and generates a current by a mechanism such as electromagnetic induction, and a type that has a battery. . In addition, IC tags have been developed that are labeled and can be easily attached to objects.

  As an attachment place of the IC tag to the wafer W, an edge portion (side surface) of the wafer W is desirable. The reason for attaching to such an edge is that when the wafer is attached to the surface of the wafer W, the wafer surface is subjected to various processes such as film formation, polishing, resist coating / development, and ion implantation. When mounted on the back surface, the wafer W is held on the back surface side in the wafer transfer device or the wafer holder, which may adversely affect the flatness of the wafer. Because there is. In addition, even when the outer edge portion of the wafer W is used, for example, in the wafer pre-alignment, the outer shape measurement is performed at a predetermined position on the outer edge portion of the wafer W. However, such outer shape measurement is performed. It is desirable to attach to parts other than the part. The thickness of the wafer W is, for example, about 800 μm to 1000 μm in the case of a silicon wafer, and an IC tag currently being developed is very small with a side of 500 μm or less and a thickness of 100 μm or less. Since it is expected to be further reduced in size and thickness in the future, it can be sufficiently attached to the edge portion.

  When the IC tag is once removed before the above-described various processing of the wafer W and is attached again after the processing, for example, the IC tag Tag is attached to the edge of the wafer W as shown in FIG. Can be directly attached diagonally to the lower side. In this case, if it sticks from adhesive films, such as a die attach film, attachment and removal with respect to the wafer W can be made easy, and it is convenient. When the edge of the wafer W is rounded as shown in the figure, the corresponding portion of the wafer W can be polished obliquely and attached to the polished surface. In addition, since it takes time to attach and detach the IC tag Tag before and after processing, when it is desired to keep it attached during processing, for example, as shown in FIG. The lower side (upper side is also acceptable) is cut into a notch, and a silicone adhesive or polyimide hybrid die attach adhesive with excellent adhesiveness, durability, and high-temperature stability is applied to the side of the notch. The IC tag Tag is preferably protected with a coating material Co such as a silicone resin.

  Further, in order to realize this advance information communication system, an IC tag is also attached to the reticle R. The IC tag in this case is the same as that for the wafer W described above. As shown in FIG. 12, the reticle R has a pattern forming surface PF in which a desired pattern is formed of, for example, Cr (chrome) on one surface of a transparent glass substrate, and the reticle R is provided around the pattern forming surface PF. In order to prevent unnecessary light from passing through, a light shielding band BP is formed of Cr (chromium) or the like. The IC tag Tag is attached to one side of the reticle R. It should be noted that the IC tag Tag is desirably provided so as to be embedded inside one side of the reticle R so as not to hinder the conveyance of the reticle R by the conveyance mechanism.

  A schematic configuration of the IC tag and its writing / reading device will be described with reference to FIG. The IC tag Tag includes a communication unit 81, a communication control unit 82, a control unit 83, and a memory 84. The write / read device RW (RW1, RW2) includes a communication unit 85 and a control unit 86. The communication unit 81 of the IC tag Tag transmits and receives information by wireless communication with the communication unit 85 of the writing / reading device RW. For example, when performing communication by radio waves, an antenna is provided. When communication is performed using infrared rays, an infrared light emitting unit and a light receiving unit are provided. The control unit 86 of the writing / reading device RW, depending on the position (target device) where the writing / reading device RW is provided, the wafer measuring instrument 400, the reticle measuring instrument 800, the main control system 20 of the exposure apparatus 200, It is connected to the analysis system 600 or the like.

  The communication control unit 82 of the IC tag Tag controls communication performed via the communication unit 81. Specifically, when information (preliminary measurement information) wirelessly transmitted from the communication unit 85 of the writing / reading device RW via the antenna (not shown) is received by the antenna (not shown) of the communication unit 81 Outputs the received information to the control unit 83, and transmits the information output from the control unit 83 from the communication unit 81 to the writing / reading device RW via the antenna.

  The control unit 83 performs input / output control of information with the communication control unit 82, reads information stored in the memory 84, and performs control to write new information into the memory 84 when received. . The memory 84 is composed of a semiconductor memory, for example. Here, the semiconductor memory used as the memory 84 may be any of a volatile memory such as a DRAM, a non-volatile memory such as a flash memory and an MRAM (Magnetic RAM).

  A plurality of write / read devices RW are provided in the exposure system as necessary. Here, as shown in FIG. 4, a write / read device RW1 is provided in the wafer measuring instrument 400 (or its vicinity). A writing / reading device RW2 is provided on wafer stage WST (or in the vicinity thereof) of exposure apparatus 200. Although not shown, a writing / reading device RW is provided on the reticle measuring instrument 800 and the reticle stage RST of the exposure apparatus 200, respectively. The control unit 86 of the writing / reading devices RW, RW1, and RW2 is connected to the wafer measuring device 400, the reticle measuring device 800, and the main control device 20 of the exposure apparatus 200 so as to be electrically communicable with each other. When the wafer measuring instrument 400 and the reticle measuring instrument 800 only write information to the IC tag Tag and do not read the information, the writing instrument without a reading function is used, and the exposure apparatus 200 uses the IC tag. When only reading information from the Tag and not writing information, a reading device without a writing function may be used.

  Note that since the analysis system 600 performs part or all of processing (excluding measurement processing) by the wafer measuring instrument 400 and the reticle measuring instrument 800, here, the wafer measuring instrument 400 or reticle measurement is performed via a network such as a LAN. The analyzer 800 and the analysis system 600 communicate with each other, but the analysis system 600 is also provided with a writing / reading device RW to be written to the IC tag Tag of the wafer W by the wafer measuring instrument 400 or the reticle measuring instrument 800. The pre-measurement information may be read by the writing / reading device RW, necessary processing may be performed, and the processing result may be written to the IC tag Tag of the wafer W as pre-measurement information.

[Wafer process]
Next, a process for the wafer W will be briefly described with reference to FIG. First, a process start command is output from the in-factory production management host system 700 in FIG. 1 to the main controller 20 via the network and the exposure process management controller 500. The main controller 20 outputs various control signals to the exposure apparatus 200, the coater unit 310, the developer unit 320, and the wafer measuring instrument 400 based on this processing start command. When this control signal is output, one wafer taken out from the wafer carrier 302 is transferred to the resist coater 311 through the transfer line 301 and coated with a photoresist, and the pre-baking device is sequentially applied along the transfer line 301. After passing through 312 and the cooling device 313 (S10), it is carried into the stage device of the in-line measuring instrument 400, and an alignment mark pre-measurement process is performed (S11). However, here, the pre-measurement process (S11) is performed after the resist process (S10), but this order may be reversed.

  In the pre-measurement process (S11) in the wafer measuring instrument 400, the edge measurement of the wafer W, the position measurement of the search alignment mark, the measurement of the position of the fine alignment mark, the measurement of the flatness of the wafer W, and the like are performed. Further, if necessary, the suitability of the mark as a mark to be detected by the exposure apparatus 200 is determined based on the mark raw signal waveform data output from the image sensor provided in the wafer measuring instrument 400 or the data obtained by signal processing thereof. In accordance with the evaluation criteria, a score indicating the level of the evaluation is calculated. The measurement result in the pre-measurement process (S11), the suitability of the mark, and the score are written / read out to the IC tag attached to the wafer W on which the measurement is performed, together with the raw signal waveform data as necessary. (S12).

  In the wafer measuring instrument 400, in order to reduce the processing load on the main controller 20 of the exposure apparatus 200, a part or all of the arithmetic processing is performed, and the calculation result is written in the IC tag. Also good. For example, a mark (a mark to be measured) when measuring the alignment mark of the wafer W by the exposure apparatus 200, the number of marks, and illumination conditions (for example, illumination wavelength, illumination intensity, dark field illumination or bright field illumination, An example of the process for optimizing whether or not illumination is performed via a phase difference plate can be given. Such an arithmetic processing may be performed not by the wafer measuring instrument 400 but by part or all of it by the analysis system 600. The preliminary measurement process includes not only the actual measurement process but also such an arithmetic process, and the preliminary measurement result includes not only the actual measurement result but also the arithmetic process result.

  The wafer W for which the pre-measurement processing has been completed is transferred to the vicinity of the exposure apparatus 200 on the transfer line 301 and transferred to the transfer robot 54. The transfer robot 54 transfers the received wafer W onto the table 51, and the table 51 holds the wafer W by suction. At this time, it is assumed that the position of the wafer W in the X-axis direction, the Y-axis direction, and the direction of the notch (or OF) is roughly adjusted by an alignment apparatus (not shown). The wafer transfer arm 52 turns to the −Y side of the turntable 51 by the arm driving mechanism 53 and receives the wafer W held on the table 51. Then, the wafer transfer arm 52 holding the wafer W is driven to a predetermined position (position where the wafer W can be delivered) in the space of the carry-in arm 36 waiting above the wafer load position. The wafer W held by the arm 52 is carried into the space portion of the carry-in arm 36 described above.

  In this state, the stage control device 19 drives the vertical movement / rotation mechanism 38 to raise the carry-in arm 36 by a predetermined amount, and when the carry-in arm 36 reaches a predetermined position, the wafer by the wafer transfer arm 52 is moved. The suction of W is released at an appropriate timing, and vacuum suction of the wafer W by the loading arm 36 is started at an appropriate timing (vacuum is turned on). When the loading arm 36 is raised until the wafer W is completely supported by the loading arm 36, the stage control device 19 retracts the wafer transfer arm 52 to the −Y side. Thereby, the delivery of the wafer W from the wafer transfer arm 52 to the carry-in arm 36 is completed (S13).

  When the main controller 20 confirms the completion of the delivery of the wafer W based on, for example, an output of a sensor (not shown) that detects a change in pressure in the vacuum suction path connected to the carry-in arm 36, the stage controller 19 Is instructed to move (insert) the background plate below the wafer W.

  Based on the output of a sensor (not shown), main controller 20 confirms that the background plate has been inserted below the wafer, and instructs stage controller 19 to perform pre-alignment measurement of wafer W. Based on this instruction, the stage control device 19 starts measuring the outer edge of the wafer W using the measurement units 40 a to 40 c constituting the pre-alignment device 32. That is, pre-alignment of the wafer W using the wafer pre-alignment apparatus 32 is started in this way (S14).

  In this pre-alignment, three regions (VA, VB, VC) in the vicinity of the outer edge of the wafer W shown in FIG. The imaging result is sent to the pre-alignment apparatus main body 34. The pre-alignment apparatus main body 34 calculates the center position and rotation amount of the wafer W held by the loading arm 36 based on the imaging data, and the stage control apparatus. 19 to the main control device 20. After completion of the pre-alignment process, the stage controller 19 notifies the main controller 20 of information on the center position, notch position, and radius of the wafer W calculated by the pre-alignment apparatus main body 34 and the main control. The background board is retracted based on an instruction from the apparatus 20.

  On the other hand, main controller 20 instructs stage controller 19 to move wafer stage WST to the wafer loading position (S15). Thereby, the stage control device 19 moves the wafer stage WST to the wafer loading position via the wafer driving device 15 while monitoring the measurement value of the wafer laser interferometer 24. With the above operation, the carry-in arm 36 and the wafer stage WST are overlapped in the vertical direction at and above the wafer load position. At this time, the stage control device 19 sets the wafer at a position where those errors are canceled based on the X, Y error information among the X, Y, θz error information of the wafer W described above. The stage WST may be positioned. If the position of wafer stage WST is set to the design value without considering the pre-alignment result (offset) at this time, the position of wafer stage WST at the time of measurement of a search alignment mark described later is set to X , Y may be adjusted based on the error information. At this time, as will be described later, the position of wafer stage WST is set so that the position shift amount of the search alignment mark in the external reference coordinate system of wafer W measured by wafer measuring instrument 400 is canceled. Further correction may be made.

  When wafer stage WST reaches the wafer loading position, main controller 20 raises the center table and lowers loading arm 36 to a position where wafer W is placed on the center table. At this time, when the carry-in arm 36 reaches a predetermined position, the stage control device 19 releases the vacuum suction on the wafer W with respect to the carry-in arm 36, and immediately after that, the vacuum suction on the wafer W by the center table is performed at an appropriate timing. Let it begin. The loading arm 36 continues to descend until the wafer W is supported only by the center table, that is, until the hook portion of the loading arm 36 is completely separated from the wafer W. Thereafter, stage controller 19 moves wafer stage WST in the + Y direction when wafer W is completely held by the vacuum suction force of the center table.

  Further, the stage control device 19 lowers the center table 30 until it is submerged in the wafer holder 18 and places the wafer W on the wafer holder 18. At this time, the stage control device 19 releases the vacuum suction of the center table 30 when the center table 30 reaches a predetermined position, and starts the vacuum suction by the wafer holder 18 at an appropriate timing. The wafer W is sucked and held. As described above, the errors in X, Y, and θz of the wafer W measured by the pre-alignment apparatus 32 are canceled by the above-described rotation of the loading arm 36 and the correction of the position of the wafer stage WST. Is held at a desired position on wafer stage WST. On the other hand, the carry-in arm 36 is raised to the original position.

  When the wafer load (S15) is completed, main controller 20 reads the pre-measurement information from the IC tag attached to wafer W via write / read device RW2 (S16). Next, when an “exposure preparation end command” is sent from the stage control device 19 to the main control device 20, the main control device 20 receives the “exposure preparation end command” and confirms the end of the wafer exchange described above. The stage controller 19 is instructed to move the wafer stage WST to the wafer alignment start position. Thereafter, the processing shifts to the wafer W alignment sequence. The stage control device 19 moves the wafer stage WST to a wafer alignment start position along a predetermined path via the wafer driving device 15 while monitoring the measurement value of the wafer laser interferometer 24 based on the above instruction. At this time, wafer stage WST moves in the opposite direction in the −X direction by a predetermined distance from the standby position, that is, on the same path as when moving to the wafer load position.

  After the movement of wafer stage WST to the wafer alignment start position is completed, search alignment is performed (S17). The search alignment is a rough alignment that is performed so that the fine alignment mark falls within the imaging field of the alignment system ALG in the fine alignment performed later at a high magnification. The alignment system ALG is set to a low magnification on the wafer W. This is done by measuring the search alignment mark.

  Next, fine alignment is performed (S18). Main controller 20 sequentially moves wafer stage WST via stage controller 19 to align alignment marks (wafer marks) attached to a predetermined shot area (sample shot) on wafer W. Detection is performed sequentially using the system ALG. Using this detection result (relative position between each mark and the detection center of the alignment system ALG) and the measurement value of the wafer laser interferometer 24 at the time of each mark detection, the position of the fine alignment mark of the sample shot is obtained. Based on the obtained position, EGA (Enhanced Global Alignment) calculation is performed, and the entire wafer is rotated, orthogonality, scaling in the X and Y directions (magnification error), and linear errors represented by offsets in the X and Y directions. Are calculated to obtain an array coordinate system, and the array coordinates of the shot area on the wafer W are calculated based on the calculation result. Here, the X position and Y position of wafer stage WST at the time of wafer alignment are measured values on the measurement axis in the Y-axis direction passing through optical axis AX of projection optical system PL and the detection center of alignment system ALG, and the alignment system. It is managed based on the measurement value on the measurement axis in the X-axis direction passing through the detection center of ALG.

  After fine alignment, main controller 20 moves wafer stage WST according to the obtained arrangement coordinates, thereby performing exposure by accurately superimposing each shot area on wafer W on the projection position of the reticle pattern (S19). ). However, since the exposure apparatus 200 performs scanning exposure, during actual exposure described later, the wafer stage WST is moved around the center of the shot obtained by moving the wafer stage WST by the baseline amount from the obtained arrangement coordinate position. The movement to the scanning start position (acceleration start position) for exposure of each shot shifted in the scanning direction by a predetermined distance from the position. After completion of exposure, wafer W is unloaded from wafer stage WST using a wafer unloader (not shown) (S20).

  Wafers W unloaded from wafer stage WST are transferred to transfer line 301 of track 300 by a wafer unloader and unload robot (not shown), and then sequentially post bake device 321 and cooling device 322 along transfer line 301. And sent to the developing device 323. Then, in the developing device 323, a resist pattern image corresponding to the device pattern of the reticle is developed on each shot area of the wafer W (S21). The developed wafer W is inspected by the measuring device when an in-line measuring device 400 for measuring the line width of the pattern formed, overlay error, etc., or a separate measuring device is provided as necessary. Housed in a wafer carrier 303.

  Thereafter, the wafer W accommodated in the wafer carrier 303 is transported to another processing apparatus, and etching (S22, scrapes off a portion not protected by the resist) and resist stripping (S23, removing unnecessary resist). Etc. are executed. By repeatedly performing the processes of S10 to S23 described above, multiple circuit patterns are formed on, for example, one lot of wafers stored in the wafer carrier 302.

  The wafer process described above is performed in each substrate processing apparatus, and each substrate processing apparatus is controlled and managed by the exposure process management controller 500 in an integrated manner. The exposure process management controller 500 stores various information such as various information for controlling a process for each lot or each wafer processed by the exposure system 100, various parameters for that, or exposure history data in a storage device attached thereto. Accumulate information. Based on these pieces of information, each exposure apparatus 200 is controlled and managed so that appropriate processing is performed on each lot. In addition, the exposure process management controller 500 uses an alignment condition (various conditions used in alignment measurement (number of sample shots and arrangement, multi-point method in a shot or one-point method) used for alignment processing in each exposure apparatus 200. The algorithm used in signal processing, etc.) is obtained and registered in each exposure apparatus 200. The exposure process management controller 500 also stores various data such as EGA log data measured by the exposure apparatus 200, and appropriately controls and manages each exposure apparatus 200 based on these data.

[Reticle pre-measurement and transfer processing]
Next, preliminary measurement processing and conveyance processing of the reticle R will be briefly described with reference to FIG. As an example, it is assumed that reticle measuring instrument 800 measures the flatness of reticle R. As shown in FIG. 15, first, under the control of the in-factory production management system 700, the exposure process management controller 500 loads a reticle R to be loaded on the exposure apparatus 200 by a reticle transport system (not shown). It is conveyed to reticle measuring instrument 800 and loaded onto reticle holder RH ′ (S30). Next, the reticle measuring instrument 800 measures a surface shape corresponding to the pattern surface of the reticle R in a state of being held by the reticle holder RH ′. The measured surface shape data R (x, y) (x and y are position coordinates in the X-axis direction and the Y-axis direction with the pattern center of the reticle R as the origin) is sent via the writing / reading device RW. The data is written on the IC tag attached to the reticle R (S31).

  Next, the reticle R is unloaded from the reticle measuring instrument 800 by a reticle conveyance system (not shown), and the reticle conveyance system conveys the reticle R to the exposure apparatus 200 (S33). Thereafter, the reticle R is sucked and held on the reticle holder. The main controller 20 of the exposure apparatus 200 reads the pre-measurement information from the IC tag attached to the reticle R via the writing / reading apparatus RW (S34), and the reticle alignment system (not shown) is read from the exposure apparatus 200. The preparatory work relating to the reticle R such as the reticle alignment and the baseline measurement is instructed to be performed using a reticle alignment system and an alignment system ALG (not shown) (S35).

  The reticle measuring instrument 800 determines whether or not the flatness of the pattern surface of the reticle R is abnormal, in other words, whether or not the reticle R cannot satisfy the required accuracy regarding the flatness. Here, an index value relating to the flatness is calculated from the surface shape data of the pattern surface of the reticle R obtained as described above, and the above determination is made based on the value. For example, here, if the difference between the maximum value and the minimum value of the surface position in the surface shape data is not within the allowable range, the reticle R is determined to be abnormal in flatness. If this determination is affirmed, the in-factory production management host system 700 is notified, the host system 700 instructs to reject the reticle R, and the process ends.

[Preliminary measurement processing and processing in the exposure apparatus corresponding thereto]
(1) Alignment Optimization The wafer measuring instrument 400 receives design position information and mark detection parameters (signals) of an alignment mark to be measured in the exposure apparatus (alignment sensor ALG) from the exposure apparatus 200 or the production management host system 700 in the factory. Parameters relating to the waveform processing algorithm, such as slice level, are acquired. Next, the stage device is driven to measure the position of the alignment mark while sequentially positioning the mark to be aligned on the wafer W in the vicinity of the detection position of the wafer measuring instrument 400.

  Next, on the basis of the mark raw signal waveform data output from the image sensor or data obtained by signal processing thereof, the suitability of the mark as a mark detected by the exposure apparatus 200 is evaluated according to a predetermined evaluation standard, and the level of the evaluation The score which shows is calculated. When the score is better than a predetermined threshold value, information indicating that the score and the mark are appropriate as a mark measured by the exposure apparatus 200 is written on the IC tag of the wafer W, and If the score is worse than a predetermined threshold value, information indicating that the score and the mark are inappropriate as a mark to be measured by the exposure apparatus 200 is used as pre-measurement information via the writing / reading device. Write to IC tag. If it is determined as defective, it is desirable to write the mark raw signal waveform data to the IC tag together with the score and information indicating the defect. Further, the signal waveform data of all marks measured by the wafer measuring instrument 400 may be written to the IC tag. However, when the signal waveform data is written for all the measurement marks, there is a problem from the viewpoint of the storage capacity and communication time of the IC tag. Since there is a possibility, the measured mark signal waveform data may be written to the IC tag only for the mark determined to be inappropriate or the mark determined to be unmeasurable (measurement error mark).

  In the exposure apparatus 200, the pre-measurement information written in the IC tag of the wafer W is read by the main controller 20 via the writing / reading device, and based on the pre-measurement information, the measurement target is measured by EGA measurement. The optimum sample shot is selected, or mark detection parameter optimization processing is performed. When the mark detection parameter optimization processing is performed by the wafer measuring instrument 400 and the processing result is written in the IC tag, the exposure apparatus 200 only needs to read the processing result.

  Here, the detection result score described above will be described. After obtaining multiple feature quantities such as mark pattern width error, which is the feature quantity in the mark signal pattern, for each pattern, the weight is optimized for each feature quantity and summed to find the total value obtained as the detection result score And the presence / absence of the mark (presence / absence) is determined by comparison with a preset threshold value. Here, in order to correctly determine whether the mark raw signal waveform data is appropriate or not, it is desirable to optimize the weighting of each of the plurality of feature amounts for each exposure process, lot, and mark structure. More specifically, the edge part of the mark raw signal waveform data is detected and the pattern width regularity (for example, uniformity) and the pattern interval regularity (for example, uniformity), which are the features of the mark, are used as feature amounts. Ask. Here, “edge” refers to a boundary between a pattern portion and a non-pattern portion forming a mark, such as a boundary between a line portion and a space portion in a line-and-space mark.

  In the pre-measurement processing by the wafer measuring instrument 400, in addition to optimization of marks and mark detection parameters, the number of marks, mark arrangement, alignment focus offset, alignment illumination conditions (illumination wavelength, bright / dark field, illumination intensity, phase difference illumination) The EGA calculation mode can also be designated as an optimization target. In this case, an EGA residual error component for each processing condition is obtained, and a processing condition that minimizes this residual error component is employed.

[Shot Arrangement Correction (GCM)]
GCM (Grid Compensation for Matching) corrects non-linear shot arrangement errors caused by non-linear deformation of wafers due to process processing such as polishing and thermal expansion, stage grid differences between exposure apparatuses, and differences in wafer adsorption state. Is.

First, a shot arrangement deformation calculation model used for EGA is shown below.
(A) The shot array deformation calculation model in normal EGA (up to the first order) is as follows.
ΔX = Cx_10 Wx + Cx_01 Wy + Cx_sx Sx + Cx_sy Sy + Cx_00 (Equation 1)
ΔY = Cy_10 Wx + Cy_01 Wy + Cy_sx Sx + Cy_sy Sy + Cy_00 (Formula 2)
The meaning of each variable is as follows.
Wx, Wy: Position of the measurement point with the wafer center as the origin
Sx, Sy: Measurement point position with the shot center as the origin
Cx_10: Wafer scaling X
Cx_01: Wafer rotation (Y axis)
Cx_sx: Shot scaling X
Cx_sy: Shot rotation (Y axis)
Cx_00: Offset X
Cy_10: Wafer rotation (X axis)
Cy_01: Wafer scaling Y
Cy_sx: Shot rotation (X axis)
Cy_sy: Shot scaling Y
Cy_00: Offset Y
If expressed using the above variables, the wafer orthogonality is-(Cx_01 + Cy_10) and the shot orthogonality is-(Cx_sy + Cy_sx).

  Depending on which of the above parameters is used, the EGA calculation model (statistical processing mode) is referred to as a 6-parameter model (normal EGA model), a 10-parameter model (multi-point model within shot), or an average model within shot. Sometimes. The 6-parameter model is a model that uses wafer scaling X, Y, wafer rotation X-axis, Y-axis, and offset X, Y among the parameters described above. The 10-parameter model is a model that uses a 6-parameter model that is obtained by adding a total of four parameters of shot scaling X and Y and shot rotation X-axis and Y-axis. The in-shot average model averages the measured values of a plurality of marks in a shot to calculate one representative value for the shot, and uses the same parameters (six parameters) as the above six-parameter model. This model performs EGA calculation of each shot position.

(B) The shot arrangement deformation calculation model up to the second order of the stage coordinates is as follows.

ΔX = Cx_20 Wx ² + Cx_11 Wx Wy + Cx_02 Wy ²
+ Cx_10 Wx + Cx_01 Wy
+ Cx_00
+ Cx_sx Sx + Cx_sy Sy (Formula 3)
ΔY = Cy_20 Wx ² + Cy_11 Wx Wy + Cy_02 Wy ²
+ Cy_10 Wx + Cy_01 Wy
+ Cy_00
+ Cy_sx Sx + Cy_sy Sy (Formula 4)

(C) The shot arrangement deformation calculation model up to the third order of the stage coordinates is as follows.
ΔX = Cx_30 Wx ³ + Cx_21 Wx ² Wy + Cx_12 Wx Wy ² + Cx_03 Wy ³
+ Cx_20 Wx ² + Cx_11 Wx Wy + Cx_02 Wy ²
+ Cx_10 Wx + Cx_01 Wy
+ Cx_00
+ Cx_sx Sx + Cx_sy Sy (Formula 5)
ΔY = Cy_30 Wx ³ + Cy_21 Wx ² Wy + Cy_12 Wx Wy ² + Cy_03 Wy ³
+ Cy_20 Wx ² + Cy_11 Wx Wy + Cy_02 Wy ²
+ Cy_10 Wx + Cy_01 Wy
+ Cy_00
+ Cy_sx Sx + Cy_sy Sy (Formula 6)

  In the case of measuring one point in a shot, the shot correction coefficients Cx_sx, Cx_sy, Cy_sx, and Cy_sy in (Expression 1) to (Expression 6) are excluded (that is, set to “0”).

  When the target wafer W is a GCM measurement target wafer, a measurement similar to the alignment measurement in the exposure apparatus 200 is executed as a pre-measurement process on a measurement shot designated in advance by the wafer measuring instrument 400, The measurement result or a higher-order correction coefficient optimized based on the measurement result is written to the IC tag of the wafer W. In exposure apparatus 200, the higher-order correction coefficient is read from the IC tag, EGA measurement / calculation is separately performed, and the higher-order correction coefficient read from the IC tag is applied to the EGA measurement / calculation result to obtain a shot arrangement. And exposure processing is performed according to this arrangement. That is, a linear correction of wafer deformation (correction of linear component) is performed as a result of performing normal EGA calculation on the measurement shot in the exposure apparatus 200, and a high-order correction obtained by the wafer measuring instrument 400 and written in the IC tag. In combination with nonlinear correction of wafer deformation by a coefficient (correction of nonlinear component error), shot array deformation correction is performed and exposure processing is executed.

  About the difference of the non-linear component (non-linear component of the wafer deformation obtained from the measurement of the wafer deformation (wafer mark)) between the in-line measuring instrument 400 and the exposure apparatus 200, the reference wafer is used in advance. The correction value is calculated in advance. At this time, either the EGA measurement result or the overlay measurement result measured for the reference wafer is used. It should be noted that, based on the general tendency of the shot arrangement deformation calculated in the pre-measurement step by the wafer measuring instrument 400, the exposure apparatus 200 side in advance for each corresponding order (usually up to the third order, but may be the fourth order or higher). The higher order correction coefficient corresponding to the optimum order and the correction coefficient may be selected from among the plurality of higher order correction coefficients registered in (1).

[Distortion correction (SDM)]
SDM (Super Distortion Matching) obtains the distortion of the previously exposed apparatus for each lot from the distortion data and lot history of the projection optical system of each exposure apparatus registered in the database, and distortion of the apparatus to be exposed from now on And for each exposure area (blind position / offset), optimal distortion matching is performed for the lot.

  When performing distortion correction, a parameter file, a stage parameter file, and a reticle manufacturing error file of optical elements such as lenses for each exposure apparatus 200 are acquired. Distortion by controlling an imaging characteristic adjusting device (MAC1) that adjusts the position and inclination of an optical element such as a lens in the projection optical system, which is mounted for controlling the imaging characteristics of the projection optical system of the exposure apparatus. Change shape and optimize matching between devices. If the exposure apparatus is a scan type, the imaging characteristics can be adjusted by changing the stage parameters.

  The wafer measuring device 400 performs this distortion measurement as a pre-measurement process. Thereby, in addition to distortion correction in units of lots by comparison between exposure apparatuses in the previous process and the next process, distortion correction in units of the specified number of wafers and specified shots is possible.

  Specifically, distortion correction (SDM) by in-line pre-measurement is performed as follows. It is assumed that the distortion correction coefficient specified (prepared) by the SDM server (here, a part of the exposure process management controller 500 in FIG. 1) is used. First, EGA measurement is performed in the exposure apparatus 200, and exposure processing is performed by applying the distortion correction coefficient to the EGA measurement result. The distortion correction coefficient is used in the distortion of the projection optical system of the other machine (exposure apparatus that prints the pattern of the previous layer on the wafer) and the current machine (from now on, where the previous layer is to be overprinted). In consideration of the difference from the distortion of the projection optical system of the exposure apparatus), this is a distortion correction coefficient optimized when performing overlap exposure by the own machine.

  Next, pre-measurement is performed on the measurement shot designated in advance by the wafer measuring instrument 400, and an optimized higher-order correction coefficient (information on the image distortion of the projection optical system of another exposure apparatus (other machine)) is optimized. Is written into the IC tag of the wafer W. In the exposure apparatus 200, the higher-order correction coefficient is read from the IC tag of the wafer W, and the internal memory of the exposure apparatus 200, the memory attached to the management controller 500 (the above-described SDM server), or the host system 700 is attached. The distortion information of the projection optical system of the exposure apparatus 200 used in the current process (information relating to the image distortion of the projection optical system used in the current process) stored and managed in advance in the memory is read.

  Next, based on the higher-order correction coefficient read from the IC tag (information related to the distortion of other machine) and the distortion information of the own machine read from the SDM server etc. Distortion distortion coefficient that is optimal for the process (the distortion of the pattern formed on the wafer by the exposure of the own machine matches the distortion of the pattern already formed on the wafer by the other machine (the pattern of the previous layer)) Therefore, an optimized correction coefficient and image distortion correction information) are calculated.

  Next, in the exposure apparatus (own machine) 200, means for adjusting the imaging characteristics of the projection optical system by applying the optimized distortion correction coefficient (the lens in the projection optical system is driven, the pressure between the lenses) The amount of driving (parameters), or the stage parameters such as the scanning speed of the stage during pattern transfer for the scanning exposure apparatus. An exposure process is performed under the set parameters.

  A process for optimizing the distortion correction coefficient (SDM correction value) by the wafer measuring instrument 400 will be described. First, a pre-measurement process is performed in the wafer measuring instrument 400, the order and the correction coefficient to be optimized by the distortion correction are specified, and the correction coefficient is calculated. As the designation of the order to be optimized, the calculation model shown in the calculation formulas (Formula 5) and (Formula 6) is used for the third order, and the calculation formulas (Formula 3) and (Formula 4) for the second order. Use the calculation model shown in. However, in the case of distortion correction, the shot correction coefficients Cx_sx, Cx_sy, Cy_sx, and Cy_sy in (Expression 1) to (Expression 6) are excluded (= 0), and Wx and Wy are the positions of measurement points with the shot center as the origin. To do.

  The designation of the correction coefficient to be optimized is to exclude (= 0) correction coefficients having a high correlation in order to stabilize the correction result. For example, in the case of the third-order term, a stable result of high-order correction may be obtained by excluding the Wx2 Wy and Wx Wy2 correction coefficients from the Wx3, Wx2 Wy, Wx Wy2, and Wy3 coefficients. As the higher order increases, the exclusion specification of the correction coefficient having higher correlation becomes more effective.

  Next, after jump data is rejected, the pre-measured wafers and shots (jump data is rejected) are averaged for each corresponding order (second order, third order, fourth order, fifth order,...). As for the second correction coefficient, a higher-order correction coefficient that minimizes the residual sum of squares after higher-order correction is selected as a coefficient used for distortion correction among combinations of optimization conditions. In the jump data rejection, data whose residual sum of squares after high-order correction for each shot exceeds a threshold value is excluded. A value obtained by dividing the variance of the higher-order correction position by the variance of the measurement result position instead of the residual sum of squares (referred to as a determination coefficient and taking a value of 0 to 1. The closer to 0, the greater the residual. The variance may be a value that takes into account the variance of the high-order correction position and the variance of the residual).

[Focus step correction]
The focus step correction by the prior measurement by the wafer measuring instrument 400 is performed as follows. First, it is determined whether or not it is 1ST exposure (exposure for the first layer). In the case of 1ST exposure, exposure is performed by focusing without device level difference correction. If it is not 1ST exposure, it is determined whether or not the step data is updated (if there is no previous data, a new step data is created). If the step data is updated, the wafer measuring instrument 400 performs alignment, Device step measurement is performed for the number of measurement shots. Next, a step correction amount (data) is calculated and written to the IC tag of the wafer W. In the exposure apparatus 200, the step data of each measurement shot is read from the IC tag by the number of times of measurement, converted to the in-shot coordinate system, and averaged within the same shot. At this time, the positional deviation of the detection point is interpolated by least square approximation, spline, Fourier series, or the like, and the position in the step data is adjusted. For each measurement shot, grid-like data arranged at a specified pitch in the X and Y directions with respect to the shot center position is obtained. Also at this time, an interpolation function according to need is used.

  Appropriate offsets and weights are set for data at selected positions in the grid-like data, and an approximate surface is calculated in units of measurement shots. This approximate surface may be a flat surface or a curved surface. Then, the step data for each measurement shot is converted into difference data (offset data) from the approximate plane. However, step data that is more than the first threshold specified by the parameter from the approximate surface is excluded from the approximate surface calculation target.

  Further, data (abnormal value data) separated from the approximate surface by a second threshold or more designated as a parameter is detected, and measurement shots having the number of abnormal value data or more designated by the parameters are unsuccessful shots, and the remaining Level difference data for only successful shots is averaged to calculate a device level difference correction amount. The exposure apparatus 200 performs an exposure process after performing the focus adjustment based on the step data correction amount.

[Focus, synchronization accuracy, exposure correction, etc.]
The wafer measuring instrument 400 measures the line width and shape of the exposure pattern formed in the previous process on the wafer W, and other information related to pattern defects, evaluates the quality of the pattern based on the measurement result, and determines the evaluation result. Based on the pattern, a defective shot of the pattern and a shot close to the defective are specified. Next, log data (focus trace data, exposure amount trace data, synchronization accuracy trace data, etc.), overlay measurement results, and EGA calculation results for the shot are acquired from the exposure apparatus, and these data are analyzed. The overlay measurement result may be obtained from a measuring apparatus other than the exposure apparatus. As analysis contents, focus trace data, exposure amount trace data, and synchronization accuracy trace data are individually analyzed to predict pattern dimension control performance. Further, the overlay control performance is predicted from the overlay measurement data and the EGA (alignment) calculation result. Based on these prediction results, a correction amount for the focus / synchronization accuracy / exposure amount in the next lot process is calculated, a shot, a wafer or a lot to be rejected is determined, and the correction amount and the rejection determination result are obtained. Write to the IC tag of the wafer W. The exposure apparatus 200 reads the correction amount and the rejection determination result from the IC tag of the wafer W, performs focus correction, stage synchronization correction, and exposure amount correction, and performs a rejection process based on the rejection determination result.

[Search alignment measurement position correction and pre-alignment measurement conditions]
A search alignment error and a decrease in search alignment accuracy may occur due to a shift in the measurement position of the search alignment mark. This is because (1) an offset (for example, about 40 [um]) in an exposure apparatus in which a pre-alignment is performed after a pre-alignment in an exposure apparatus that performs a post-process (second exposure) and then a pre-process (first exposure) is performed. (2) Pre-alignment reproducibility (pre-alignment measurement error and wafer insertion error at 3σ, for example, about 15 [um]), (3) offset (for example, about 40 [um]) in the exposure apparatus related to the second exposure, (4) Pre-alignment reproducibility (pre-alignment measurement error and wafer insertion error, for example, about 15 [um] at 3σ), (5) manufacturing error of alignment sensor (FIA sensor), alignment optical system magnification tolerance, etc. (for example, about This is because the position at which the search alignment mark is measured is shifted due to the influence of 10 [um].

The necessary measurement range of the search alignment mark is as follows based on the above contents.
(1) + (3) + √ ((2) ² + (4) ² ) + (5) = 133 μm (± 66.5 μm)
Pre-alignment due to wafer warpage, variations in wafer outer edge shape, prealignment device misalignment (adjustment value of vacuum off position of arm of prealignment device, adjustment value of lift position of center table, etc.), durability of center table, etc. Due to deterioration in alignment reproducibility ((pre-alignment measurement accuracy and wafer insertion accuracy), the search alignment mark may deviate from the measurement field of view of the alignment sensor (for example, 204 × 153 [um]). It is required to reduce the variation factors (5) to (5) and place the search alignment mark in the search measurement field of view.

  The wafer measuring instrument 400 measures the wafer outer shape (usually, three locations including the notch) as prior measurement information, and measures the position of the search alignment mark in the coordinate system based on the center position and the rotation amount obtained from the wafer outer shape. Then, the amount of deviation from the design coordinates of the search alignment mark based on the wafer outer shape reference is calculated and written to the IC tag of the wafer W. The exposure apparatus 200 reads the shift amount from the IC tag and corrects the measurement position of the search alignment mark based on the read amount. As a result, the deviation due to (1) offset and (2) pre-alignment reproducibility in the exposure apparatus related to the first exposure can be corrected at the time of search alignment in the exposure apparatus related to the second exposure. It is possible to reduce alignment errors caused by the above and to improve search alignment accuracy.

  In addition, the wafer measuring instrument 400 performs the same measurement as the pre-alignment measurement as the pre-measurement information, obtains the optimum pre-alignment condition, writes this in the IC tag of the wafer W, and the exposure apparatus By reading out the optimum pre-alignment conditions from the IC tag and performing pre-alignment according to the conditions, pre-alignment measurement reproducibility can be improved, alignment errors can be reduced, and alignment accuracy can be improved. In this case, it is necessary to read the pre-measurement information from the IC tag in S16 in FIG. 14 before the pre-alignment in S14.

[Wafer flatness]
The wafer measuring instrument 400 measures the flatness of the wafer W as prior measurement information, and writes the measurement result to the IC tag of the wafer W. The exposure apparatus 200 reads flatness information as the measurement result from the IC tag. Then, focus correction is performed during exposure according to the read flatness information. If it is determined that the flatness of the wafer W exceeds the range that can be corrected by the focus correction, the reject process is performed as an abnormal wafer. Note that, when the reticle R flatness is measured by a reticle measuring instrument 800 described later, more appropriate correction is performed by performing focus correction according to the difference between the wafer flatness and the reticle flatness. be able to.

[Wafer foreign matter inspection]
The wafer measuring device 400 inspects the presence of foreign matter on the surface of the wafer W as prior measurement information, and writes the measurement result to the IC tag of the wafer W. In the exposure apparatus 200, the foreign substance information as the inspection result is read from the IC tag, and when the read foreign substance information includes the attachment of the foreign substance, the shot is rejected as an abnormal wafer or the foreign substance is attached. The exposure process for a normal shot is skipped, or the wafer surface is cleaned to remove the foreign matter.

[Wafer defect inspection]
The wafer measuring instrument 400 inspects whether or not the pattern formed on the wafer W is defective as prior measurement information, and writes the inspection result to the IC tag of the wafer W. In the exposure apparatus 200, the defect information as the inspection result is read from the IC tag, and when the read defect information indicates that there is a defect, it is rejected as an abnormal wafer, or a defective shot is skipped and is normal. An exposure process is performed for a correct shot.

[Reticle flatness]
The reticle measuring instrument 800 measures the flatness (including deflection) of the reticle R as prior measurement information, and writes the measurement result to the IC tag of the reticle R. The exposure apparatus 200 reads flatness information as the measurement result from the IC tag. Then, in accordance with the read flatness information, any, a plurality, or all of focus correction, positional deviation correction, field curvature correction, and distortion correction are performed during exposure. If it is determined that the flatness of the reticle R exceeds the range that can be corrected by these corrections, a rejection process is performed as an abnormal reticle. In addition, when the flatness of the wafer W is measured by the wafer measuring device 400 described above, more appropriate correction is performed by performing focus correction according to the difference between the reticle flatness and the wafer flatness. be able to.

[Reticle foreign body inspection]
Reticle measuring instrument 800 inspects the presence of foreign matter on the surface of reticle R as prior measurement information, and writes the inspection result to the IC tag of reticle R. The exposure apparatus 200 reads out the foreign substance information as the inspection result from the IC tag, and rejects it as an abnormal reticle when the foreign substance information includes the attachment of the foreign substance. When the reticle R is a reticle that forms a plurality of chips in one shot, that is, when patterns corresponding to a plurality of chips are formed, the chip area corresponding to the abnormal part is shielded with a brand. The exposure process is performed only in the normal chip area. Alternatively, the wafer surface is cleaned to remove the foreign matter.

[Reticle defect inspection]
The reticle measuring instrument 800 inspects the presence or absence of defects (including scratches) on the surface of the reticle R as prior measurement information, and writes the inspection result to the IC tag of the reticle R. The exposure apparatus 200 reads the defect information as the inspection result from the IC tag, and rejects it as an abnormal reticle when the defect information contains a defect. When the reticle R is a reticle that forms a plurality of chips in one shot, that is, when patterns corresponding to a plurality of chips are formed, the chip area corresponding to the abnormal part is shielded with a brand. The exposure process is performed only in the normal chip area.

  According to the above-described embodiment, the pre-measurement information as the measurement result in the wafer measuring instrument 400 or the reticle measuring instrument 800 (if any calculation, evaluation, determination, or other processing based on the measurement result is performed) (Including the processing result) is written into the IC tag attached to the wafer W on which the measurement is performed via the writing / reading device RW (RW1) provided in the wafer measuring instrument 400 or the reticle measuring instrument 800. Is loaded into the exposure apparatus 200, the pre-measurement information is read from the IC tag via the writing / reading apparatus RW (RW2) provided in the exposure apparatus 200, and the exposure apparatus performs processing related to exposure. As a result, the prior measurement information need not be managed by a host computer or the like as in the prior art, and the prior measurement information is not transmitted via the network. And the processing load on the host computer or network with the transceiver and information management can be reduced. In particular, in a relatively small exposure system, it may be disadvantageous from the viewpoint of cost and the like to provide a host computer and manage it in an integrated manner. It becomes possible to cope with low cost.

[Application to other devices or systems]
In the above-described embodiment, the wafer measuring instrument 400 or the reticle measuring instrument 800 is used as a pre-measuring device that performs a pre-measurement process, and the pre-measurement information pre-measured by the wafer measuring instrument 400 or the reticle measuring instrument 800 is attached to the wafer W. In the exposure apparatus 200, the pre-measurement information is read out from the IC tag, and the above-described various processes are performed as processes related to exposure. The relationship between the wafer measuring instrument 400 or the reticle measuring instrument 800 and the exposure apparatus 200 can be similarly applied to other measuring instruments and other processing apparatuses.

(1) Laser repair device (tester and laser processing device)
In the manufacture of a semiconductor device (for example, a semiconductor memory), processing by a laser repair device is performed as a subsequent process of the above-described lithography process. The laser repair device includes a tester that performs a probe test and a laser processing device that blows a fuse of a redundant circuit in order to relieve a defective chip that is determined to be defective by the tester. The target wafer is inspected by a tester and then transferred to a laser processing apparatus, where the corresponding fuse is blown according to the inspection result. The present invention can also be applied to such a laser repair apparatus. That is, the inspection result inspected by the tester is written as pre-measurement information on the IC tag attached to the wafer, and after the wafer is transferred to the laser processing apparatus, the inspection result is read from the IC tag by the laser processing apparatus. The fuse can be blown out in accordance with the readout and the inspection result. In this case, the tester is a pre-measurement device, and the laser processing device is another processing device.

(2) Measurement / inspection equipment (exposure equipment and measurement / inspection equipment)
After the exposure process by the exposure apparatus, the pattern formed on the wafer is checked for defects, foreign matter adhesion, and the like. Since the exposure apparatus collects various types of trace data such as focus error, synchronization accuracy, exposure amount error, and the like regarding the exposure processing on the wafer, the control failure position information (control failure shot calculated based on this trace data) Information) to the IC tag of the wafer W as pre-measurement information, and the measurement / inspection apparatus reads the pre-measurement information from the IC tag, and predicts a defective portion based on the control failure position information. By measuring and inspecting the relevant part, it becomes possible to perform highly efficient measurement and inspection in a short time. Also, the wafer number and shot position information for which the EGA random component exceeds a predetermined threshold value is written in the IC tag of the wafer W by the exposure apparatus as the pre-measurement information, and the position information is read from the IC tag by the measurement / inspection apparatus May be read and measurement / inspection may be performed. In this case, the exposure apparatus is a pre-measurement apparatus, and the wafer measurement / inspection apparatus is the other processing apparatus. In addition, the measurement / inspection device writes abnormal portions such as foreign matters and pattern defects to the IC tag attached to the wafer as pre-measurement information, and the pre-measurement information is received from the IC tag in various processing devices other than the exposure device. The corresponding processing may be performed after reading. In this case, the wafer measurement / inspection apparatus is a pre-measurement apparatus, and various processing apparatuses are the other processing apparatuses.

  Also, in reticle measurement / inspection, abnormal parts such as foreign matters and pattern defects are written as pre-measurement information on an IC tag attached to the reticle, and in various processing apparatuses thereafter, pre-measurement information is read from the IC tag. Based on the pre-measurement information, detailed inspection of the abnormal portion, relief of the abnormal portion, processing excluding the abnormal portion, reticle rejection, and the like may be performed. In this case, the reticle measurement / inspection device is a pre-measurement device, and the various processing devices are the other processing devices.

(3) In addition, among the exposure apparatus, measurement apparatus, inspection apparatus, repair apparatus, etching apparatus, film forming apparatus, oxidation / ion implantation apparatus, CMP apparatus, resist coating apparatus, and developing apparatus that process the substrate In an exposure system comprising a plurality of device-related apparatuses including at least two, one of these device-related apparatuses includes: substrate layout information, quality control information, device-related apparatus processing information, and other information. Information including at least one is written in the IC tag attached to the substrate as pre-measurement information, and the pre-measurement information is read out from the IC tag in the other one of the device-related devices. The corresponding processing may be performed according to For example, the film thickness inspection apparatus is a pre-measurement apparatus, the film formation apparatus is the other processing apparatus, and the film thickness information inspected by the film thickness inspection apparatus is written on the IC tag attached to the substrate as the pre-measurement information. In the film forming apparatus, the pre-measurement information can be read from the IC tag, and the film forming process can be performed based on the pre-measurement information. Also, the IC tag attached to the substrate using the trench measurement device as a pre-measurement device, the etching device as the other processing device, and the shape (depth, etc.) of the trench groove measured by the trench measurement device as pre-measurement information The pre-measurement information may be read from the IC tag with an etching apparatus, and the etching process may be performed based on the pre-measurement information.

[Device manufacturing method]
Next, a manufacturing process of an electronic device such as a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, or a micromachine using the exposure system described above in a lithography process will be briefly described. First, device function / performance design such as circuit design of an electronic device is performed, pattern design for realizing the function is performed, and then a mask on which the designed circuit pattern is formed is manufactured. On the other hand, a wafer (silicon substrate) is manufactured using a material such as silicon. Next, an actual circuit or the like is formed on the wafer by lithography or the like using the mask manufactured in the mask manufacturing process and the wafer manufactured in the wafer manufacturing process. Specifically, a thin film such as an insulating film, an electrode wiring film, or a semiconductor film is first formed on the wafer surface, and then a photosensitive agent (resist) is formed on the entire surface of the thin film using a resist coating apparatus (coater). Apply. Next, the resist-coated substrate is loaded onto the wafer holder of the exposure apparatus, and the mask manufactured in the reticle manufacturing process is loaded onto the reticle stage, and the pattern formed on the mask is reduced and transferred onto the wafer. To do.

  When the exposure is completed, the wafer is unloaded from the wafer holder and developed using a developing device (developer). As a result, a resist image of the mask pattern is formed on the wafer surface. Then, the wafer subjected to the development process is etched using an etching apparatus, and the resist remaining on the wafer surface is removed using, for example, a plasma ashing apparatus. Thereby, patterns such as an insulating layer and electrode wiring are formed in each shot region of the wafer. Then, an actual circuit or the like is formed on the wafer by sequentially repeating this process while changing the mask. Once a circuit or the like is formed on the wafer, assembly as a device is performed next. Specifically, the wafer is diced and divided into individual chips, each chip is mounted on a lead frame or a package, bonding for connecting electrodes is performed, and a packaging process such as resin sealing is performed. Then, inspections such as an operation confirmation test and a durability test of the manufactured device are performed, and the device is shipped as a completed device.

  The embodiment described above is described in order to facilitate understanding of the present invention, and is not described in order to limit the present invention. Therefore, each element disclosed in the above embodiment includes all design changes and equivalents belonging to the technical scope of the present invention.

  In the embodiment described above, the step-and-scan type exposure apparatus has been described as an example of the exposure apparatus. However, the present invention can be applied to a step-and-repeat type exposure apparatus. Also, not only an exposure apparatus used for manufacturing a semiconductor element or a liquid crystal display element, but also an exposure apparatus used for manufacturing a plasma display, a thin film magnetic head, and an image sensor (CCD, etc.), and a reticle or mask. In addition, the present invention can be applied to an exposure apparatus that transfers a circuit pattern onto a glass substrate or a silicon wafer. In other words, the present invention can be applied regardless of the exposure method and application of the exposure apparatus. The exposure illumination light (energy beam) used in the exposure apparatus is not limited to ultraviolet light, and may be charged particle beams such as X-rays (including EUV light), electron beams, and ion beams. Also, an exposure apparatus used for manufacturing a DNA chip or the like may be used.

FIG. 1 is a block diagram showing the overall configuration of an exposure system according to an embodiment of the present invention. 2 is a diagram showing a schematic configuration of an exposure apparatus provided in the exposure system according to the embodiment of the present invention. FIG. 3A is a diagram showing a measurement position by the measurement unit in the notch wafer, and FIG. 3B is a diagram showing a measurement position by the measurement unit in the wafer provided with the orientation flat. FIG. 4 is a view showing a schematic configuration of a coating and developing apparatus and the like connected in-line to the exposure apparatus in the embodiment of the present invention. FIG. 5 is a diagram showing a schematic configuration of a reticle measuring instrument for measuring a surface shape in the embodiment of the present invention. FIG. 6 is a diagram showing a schematic configuration of a reticle measuring instrument for pattern defect / foreign particle inspection in the embodiment of the present invention. FIG. 7 is a perspective view showing a schematic configuration of a wafer measuring instrument for measuring the wafer outer shape / mark in the embodiment of the present invention. FIG. 8 is a side view showing a schematic configuration of a wafer measuring instrument for measuring the wafer outer shape / mark in the embodiment of the present invention. FIG. 9 is a diagram showing a schematic configuration of a wafer measuring instrument for surface shape measurement in the embodiment of the present invention. FIG. 10 is a view showing an example of attaching an IC tag to a wafer in the embodiment of the present invention. FIG. 11 is a diagram showing another example of attaching an IC tag to a wafer in the embodiment of the present invention. FIG. 12 is a diagram showing an example of attaching an IC tag to a reticle in the embodiment of the present invention. FIG. 13 is a block diagram showing a schematic configuration of an IC tag and a writing / reading device according to the embodiment of the present invention. FIG. 14 is a flowchart showing processing for a wafer in the embodiment of the present invention. FIG. 15 is a flowchart showing processing for a reticle in the embodiment of the present invention.

Explanation of symbols

W ... wafer 100 ... exposure system 200 ... exposure apparatus 300 ... coating and developing apparatus 400 ... wafer measuring instrument 500 ... exposure process management controller 600 ... analysis system 700 ... production control host system 800 in the factory ... reticle measuring instrument Tag ... IC tag RW ( RW1, RW2) ... Write / read device

Claims (11)

An exposure apparatus that exposes and forms a pattern on a substrate placed on a substrate stage; and a pre-measurement device that pre-measures information about the substrate before the substrate is placed on the substrate stage. In an exposure system comprising
A wireless communication type information storage member attached to the substrate;
A writing device that writes the pre-measurement information measured by the pre-measurement device to the information storage member attached to the substrate related to the pre-measurement by wireless communication;
A reading device that reads out the pre-measurement information by wireless communication from the information storage member attached to the substrate;
A processing apparatus that is provided in the exposure apparatus and performs processing related to exposure based on the content of the preliminary measurement information read by the reading apparatus;
An exposure system comprising: The pre-measurement information measured by the pre-measurement device and written to the information storage member by the writing device is:
Appropriateness of marks formed on the substrate, evaluation results of the marks, waveform signal information obtained by the mark measurement, grid correction information, distortion correction information, shot flatness correction information, focus correction information, synchronization accuracy information, exposure The exposure system according to claim 1, comprising at least one of quantity correction information, reject determination result, substrate outer shape information, preliminary alignment information, optimum measurement conditions, and flatness information of the substrate. An exposure apparatus that exposes the substrate through a pattern formed on the mask placed on the mask stage, and pre-measures information about the mask before the mask is placed on the mask stage. In an exposure system comprising a pre-measurement device,
A wireless communication type information storage member attached to the mask;
A writing device that writes the pre-measurement information measured by the pre-measurement device to the information storage member attached to the mask related to the pre-measurement by wireless communication;
A reading device that reads out the pre-measurement information by wireless communication from the information storage member attached to the mask;
A processing apparatus that is provided in the exposure apparatus and performs processing related to exposure based on the content of the preliminary measurement information read by the reading apparatus;
An exposure system comprising:   The pre-measurement information measured by the pre-measurement device and written to the information storage member by the writing device is at least the flatness information of the mask, the defect information of the mask, and the result of foreign matter inspection on the mask surface. 4. The exposure system according to claim 3, wherein the exposure system is one. The pre-measurement device is provided independently of the exposure device,
The writing device is provided in the pre-measurement device,
The exposure system according to claim 1, wherein the reading device is provided in the exposure device. Prior to loading the substrate onto the substrate stage on which the substrate is placed, which is provided in an exposure apparatus that exposes the substrate, information relating to the substrate that is loaded onto the substrate stage is pre-measured. The first step;
A second step of writing the information measured in the first step to the wireless communication type information storage member attached to the substrate by wireless communication;
A third step of reading information from the information storage member by wireless communication, and performing a process on the substrate on the substrate stage based on the read information;
An exposure method comprising: The exposure apparatus that exposes the substrate through the pattern formed on the mask is loaded onto the mask stage before the mask is loaded onto the mask stage on which the mask is placed. A first step of pre-measuring information about the mask to be performed;
A second step of writing the information measured in the first step to the wireless communication type information storage member attached to the mask by wireless communication;
A third step of reading information from the information storage member by wireless communication and performing a process related to exposure using a mask on the mask stage based on the read information;
An exposure method comprising: A plurality of processing apparatuses including at least two of an exposure apparatus, a measurement apparatus, an inspection apparatus, a repair apparatus, an etching apparatus, a film forming apparatus, an oxidation / ion implantation apparatus, a CMP apparatus, a resist coating apparatus, and a developing apparatus. In an exposure system including a device-related apparatus,
At least one of layout information of the board, quality control information, and processing information of the device-related apparatus is stored, and a wireless communication type information storage member attached to the board;
Readout means provided in the device-related apparatus and reading out the information from the information storage member attached to the substrate by wireless communication,
An exposure system wherein predetermined processing is performed in accordance with the contents of the information read by the reading means in the device-related apparatus. A device manufacturing factory for manufacturing a device by performing predetermined processing on a substrate,
A device manufacturing plant comprising the exposure system according to claim 1. A processing system comprising a processing device for processing a substrate, and an observation device for measuring or inspecting the substrate after processing in the processing device,
A writing device for writing information related to a processing result in the processing device to a wireless communication type information storage member attached to the substrate by wireless communication;
A reading device that reads out information about the processing result from the information storage member attached to the substrate by wireless communication,
The processing system, wherein the observation device performs the measurement process or the inspection process based on the content of the information read by the reading device. The processing apparatus is an exposure apparatus that exposes a pattern on the substrate,
The processing system according to claim 10, wherein the information related to the processing result is information related to an exposure state in a plurality of exposure regions on the substrate formed by exposure by the exposure apparatus.

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