JP2010050290A - Exposure method and aligner, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain drive control of a wafer stage precisely without reducing rate of operation of an aligner. <P>SOLUTION: The position information of a wafer stage WST is measured by an encoder system in parallel with at least one of exposure operation (Fig. 8(A)) and alignment measurement operation (Fig. 8(B)), and deviation of measurement information of individual heads 64-68 of the encoder system from reference information corresponding to the measurement information is collected as calibration data. Calibration information for correcting the measurement error of individual heads is created by the collected calibration data. Then, the wafer stage is drive and controlled according to the measurement result of the encoder system and the created calibration information. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exposure method, an exposure apparatus, and a device manufacturing method, and more particularly, to an exposure method and an exposure apparatus used in a lithography process for manufacturing a semiconductor element (such as an integrated circuit) and a liquid crystal display element, and the exposure method or The present invention relates to a device manufacturing method using an exposure apparatus.

  Conventionally, in a lithography process for manufacturing electronic devices (microdevices) such as semiconductor elements (integrated circuits, etc.), liquid crystal display elements, etc., a step-and-repeat type projection exposure apparatus (so-called stepper) or a step-and-scan type Projection exposure apparatuses (so-called scanning steppers (also called scanners)) are mainly used.

  In this type of exposure apparatus, in order to transfer a reticle (or mask) pattern to a plurality of shot regions on a substrate such as a wafer or a glass plate (hereinafter collectively referred to as a wafer), a wafer stage that holds the wafer includes: For example, it is driven in a two-dimensional direction by a linear motor or the like. The position of the wafer stage is generally measured by using a laser interferometer having high stability over a long period of time.

  However, in recent years, with the miniaturization of patterns due to higher integration of semiconductor elements, the requirement for overlay accuracy has become stricter, resulting from air fluctuations caused by the temperature change and temperature gradient of the atmosphere on the beam path of the laser interferometer. Short-term fluctuations in measured values now occupy a large weight in the overlay budget.

  Therefore, an exposure apparatus that employs an encoder that has a measurement resolution comparable to or higher than that of a laser interferometer and is generally less susceptible to air fluctuations than an interferometer is proposed as a wafer stage position measurement device. (For example, refer to Patent Document 1).

  However, since a grating (scale) is used as a measurement member in the encoder, the scale is deformed due to the influence of thermal or mechanical force over time. In particular, in the exposure apparatus described in Patent Document 1, a part of the grating provided on the upper surface of the wafer stage is also used as the measurement surface of the surface position sensor. The measurement accuracy is also adversely affected.

  Therefore, the emergence of a new technology capable of substantially maintaining the high measurement accuracy of the encoder (and the surface position sensor) without reducing the throughput has been expected.

International Publication No. 2007/097379 Pamphlet

  The present invention has been made under the circumstances described above. From a first viewpoint, the present invention is an exposure method for forming a pattern on an object, the moving body moving within a predetermined plane, and the outside of the moving body. The measurement surface provided on the other of the movable body and the outside of the movable body is irradiated with measurement light, and the light from the measurement surface is received. Measuring the position information of the moving body and driving the moving body according to the position information; forming a pattern on the object held by the moving body; and markings applied to the object A step of detecting; and a step of collecting deviations of the position information from reference information corresponding to the position information in parallel with at least one of the forming step and the detecting step. Is the method.

  According to this, in the collecting step, the deviation of the position information of the moving body measured in the driving step from the reference information corresponding to the position information is collected. Therefore, by using the deviation collected in the collecting step and correcting the measurement error of the position information of the moving body by the head, the driving control of the moving body can be performed with high accuracy. Further, in the collecting step, the deviation is collected in parallel with at least one of the forming step and the detecting step. This makes it possible to collect deviations and thus correct measurement errors in the position information of the moving body by the head without reducing the throughput of the apparatus that performs the exposure method.

  According to a second aspect of the present invention, there is provided an exposure method for forming a pattern on an object, comprising at least one head provided on one of a moving body that moves within a predetermined plane and the outside of the moving body. The measurement surface provided on the other of the movable body and the outside of the movable body is irradiated with measurement light, the light from the measurement surface is received, and the positional information of the movable body is measured, Driving the moving body according to position information and calibration information for correcting the position information; forming a pattern on the object held by the moving body; and markings applied to the object In parallel with at least one of the forming step and the detecting step, position information of the moving body is measured using a reference measurement system, and the measurement information of the reference measurement system is used to measure the position of the head. Predict measurement information Collecting the deviation of the measurement information of the head with respect to the position of the irradiation point of the measurement light on the measurement surface; and creating the calibration information using the deviation collected in the collecting step And a second exposure method.

  According to this, in the collecting step, the position information of the moving body is measured using the reference measurement system, the measurement information of the head used in the step of driving from the measurement information is predicted, and the predicted measurement information is used. The deviation of the measurement information of the head obtained in the driving step is collected with respect to the position of the measurement light irradiation point on the measurement surface. In the creating step, calibration information used to correct the position information in the driving step is created using the deviation collected in the collecting step. Therefore, calibration information for correcting a measurement error depending on the position of the irradiation point of the measurement light on the measurement surface can be created, and consequently, driving control of the moving body with high accuracy is possible.

  According to a third aspect of the present invention, there is provided a step of forming a pattern on an object using any one of the first and second exposure methods of the present invention; and processing the object on which the pattern is formed. A first device manufacturing method including: an applying step.

  From a fourth aspect, the present invention is an exposure apparatus for forming a pattern on an object, the movable body holding the object and moving in a predetermined plane; the movable body and the outside of the movable body; And at least one head that irradiates measurement light to the measurement surface provided on the other of the movable body and the outside of the movable body and receives light from the measurement surface, the head A position measurement system that measures position information of the moving body based on the output of the pattern; a pattern generation device that generates a pattern on the object; a mark detection device that detects a mark attached to the object; and the position information And driving the moving body according to the pattern generation device, the pattern generation device for pattern formation, and the mark detection device for detection of the mark on the object in parallel with the position It is an exposure apparatus comprising a; controller and for collecting deviation from the reference information corresponding to the positional information of the broadcast.

  According to this, the control device collects a deviation of the position information of the moving body measured using the position measurement system from the reference information corresponding to the position information. Therefore, when the control unit drives the mobile unit, the measurement error of the positional information of the mobile unit by the head is corrected using the collected deviation, so that the drive control of the mobile unit can be performed with high accuracy. Further, the control device collects the deviation in parallel with at least one of pattern formation on the object by the pattern generation device and detection of the mark on the object by the mark detection device. This makes it possible to correct misalignment collection and, in turn, the measurement error of the position information of the moving body by the head without reducing the throughput.

  According to a fifth aspect of the present invention, there is provided a second method comprising: forming a pattern on an object using the exposure apparatus of the present invention; and performing processing on the object on which the pattern is formed. It is a device manufacturing method.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to FIGS.

  FIG. 1 schematically shows a configuration of an exposure apparatus 100 according to an embodiment. The exposure apparatus 100 is a step-and-scan projection exposure apparatus, a so-called scanner. As will be described later, in the present embodiment, a projection optical system PL and a primary alignment system AL1 (see FIGS. 4 and 5, etc.) are provided. In the following, the direction parallel to the optical axis AX of the projection optical system PL is the Z-axis direction, and the direction parallel to the straight line connecting the optical axis AX and the detection center of the primary alignment system AL1 in the plane orthogonal to this is the Y-axis direction. The direction orthogonal to the Z axis and the Y axis is defined as the X axis direction, and the rotation (tilt) directions around the X axis, the Y axis, and the Z axis are defined as the θx, θy, and θz directions, respectively.

  The exposure apparatus 100 includes an illumination system 10, a reticle stage RST, a projection unit PU, a stage apparatus 50 having a wafer stage WST, a control system for these, and the like. In FIG. 1, wafer W is mounted on wafer stage WST.

  The illumination system 10 illuminates the slit-shaped illumination area IAR on the reticle R defined by the reticle blind (masking system) with illumination light (exposure light) IL with substantially uniform illuminance. The configuration of the illumination system 10 is disclosed in, for example, US Patent Application Publication No. 2003/0025890. Here, as an example, ArF excimer laser light (wavelength 193 nm) is used as the illumination light IL.

  On reticle stage RST, reticle R having a circuit pattern or the like formed on its pattern surface (lower surface in FIG. 1) is fixed, for example, by vacuum suction. The reticle stage RST can be finely driven in the XY plane by a reticle stage drive system 11 (not shown in FIG. 1, refer to FIG. 7) including a linear motor, for example, and also in the scanning direction (left and right direction in FIG. 1). In the Y-axis direction) at a predetermined scanning speed.

  Position information (including rotation information in the θz direction) of reticle stage RST in the XY plane is formed on movable mirror 15 (or on the end face of reticle stage RST) by reticle laser interferometer (hereinafter referred to as “reticle interferometer”) 116. For example, with a resolution of about 0.25 nm. The measurement value of reticle interferometer 116 is sent to main controller 20 (not shown in FIG. 1, refer to FIG. 7).

  Projection unit PU is arranged below reticle stage RST in FIG. The projection unit PU includes a lens barrel 40 and a projection optical system PL held in the lens barrel 40. As projection optical system PL, for example, a refractive optical system including a plurality of optical elements (lens elements) arranged along optical axis AX parallel to the Z-axis direction is used. The projection optical system PL is, for example, both-side telecentric and has a predetermined projection magnification (for example, 1/4 times, 1/5 times, or 1/8 times). For this reason, when the illumination area IAR on the reticle R is illuminated by the illumination system 10, the illumination light that has passed through the reticle R arranged so that the first surface (object surface) and the pattern surface of the projection optical system PL substantially coincide with each other. The reduced image of the circuit pattern of the reticle R in the illumination area IAR (a reduced image of a part of the circuit pattern) is passed through the projection optical system PL (projection unit PU) by the IL on the second surface (image surface) side. And is formed in an area IA (hereinafter also referred to as an exposure area) IA conjugate to the illumination area IAR on the wafer W having a surface coated with a resist (sensitive agent). Then, by synchronous driving of reticle stage RST and wafer stage WST, reticle R is moved relative to illumination area IAR (illumination light IL) in the scanning direction (Y-axis direction) and exposure area IA (illumination light IL). By moving the wafer W relative to the scanning direction (Y-axis direction), scanning exposure of one shot area (partition area) on the wafer W is performed, and a reticle pattern is transferred to the shot area. . That is, in this embodiment, a pattern is generated on the wafer W by the illumination system 10, the reticle R, and the projection optical system PL, and the pattern is formed on the wafer W by exposure of the sensitive layer (resist layer) on the wafer W by the illumination light IL. Is formed.

  As shown in FIG. 1, stage device 50 drives wafer stage WST disposed on base board 12, measurement system 200 (see FIG. 7) for measuring positional information of wafer stage WST, and wafer stage WST. A stage drive system 124 (see FIG. 7) and the like are provided. As shown in FIG. 7, the measurement system 200 includes an interferometer system 118, an encoder system 150, a surface position measurement system 180, and the like.

  Wafer stage WST is supported above base board 12 by a non-contact bearing (not shown) such as an air bearing with a clearance of about several μm. Wafer stage WST can be driven with a predetermined stroke in the X-axis direction and the Y-axis direction by stage drive system 124 (see FIG. 7) including a linear motor and the like.

  Wafer stage WST includes a stage main body 91 and a wafer table WTB mounted on stage main body 91. The wafer table WTB and the stage main body 91 are directed to the base board 12 in directions of six degrees of freedom (X, Y, Z, θx, etc.) by a drive system including a linear motor and a Z / leveling mechanism (including a voice coil motor). It can be driven to θy, θz).

  At the center of the upper surface of wafer table WTB, a wafer holder (not shown) for holding wafer W by vacuum suction or the like is provided. As shown in FIG. 2, a measurement plate 30 is provided on the + Y side of the wafer holder (wafer W) on the upper surface of wafer table WTB. The measurement plate 30 is provided with a reference mark FM at the center, and a pair of aerial image measurement slit patterns (slit-shaped measurement patterns) SL are provided on both sides of the reference mark FM in the X-axis direction. In correspondence with each aerial image measurement slit pattern SL, an optical system, a light receiving element, and the like are arranged inside wafer table WTB. That is, a pair of aerial image measurement devices 45A and 45B (see FIG. 7) including the aerial image measurement slit pattern SL is provided on wafer table WTB.

In addition, a scale used in an encoder system described later is formed on the upper surface of wafer table WTB. More specifically, Y scales 39Y ₁ and 39Y ₂ are formed in regions on one side and the other side of the upper surface of wafer table WTB in the X-axis direction (left and right direction in FIG. 2). The Y scales 39Y ₁ and 39Y ₂ are, for example, reflective type gratings (for example, diffraction gratings) in which the Y axis direction is a periodic direction in which grid lines 38 having the X axis direction as the longitudinal direction are arranged at a predetermined pitch in the Y axis direction. ).

Similarly, X scale 39X ₁ , X scale 39X ₁ , and Y scale 39Y ₁ and 39Y ₂ are sandwiched between one side and the other side in the Y-axis direction (up and down direction in the drawing in FIG. 2) of wafer table WTB. 39X ₂ are formed respectively. The X scales 39X ₁ and 39X ₂ are, for example, reflection type gratings (for example, diffraction gratings) in which the X-axis direction is a periodic direction in which grid lines 37 having a longitudinal direction in the Y-axis direction are arranged in the X-axis direction at a predetermined pitch ).

  The pitch of the grid lines 37 and 38 is set to 1 μm, for example. In FIG. 2 and other drawings, the pitch of the grating is shown larger than the actual pitch for convenience of illustration.

  It is also effective to cover the diffraction grating with a glass plate having a low coefficient of thermal expansion. Here, as the glass plate, a glass plate having the same thickness as the wafer, for example, a thickness of 1 mm can be used, and the wafer table is such that the surface of the glass plate is the same height (same surface) as the wafer surface. Installed on top of WTB.

  Further, as shown in FIG. 2, a reflecting surface 17a and a reflecting surface 17b used in an interferometer system to be described later are formed on the −Y end surface and the −X end surface of the wafer table WTB.

  Further, as shown in FIG. 2, on the surface of the wafer table WTB on the −Y side, a fiducial bar extending in the X-axis direction (similar to the CD bar disclosed in the pamphlet of International Publication No. 2007/097379) (Hereinafter abbreviated as “FD bar”) 46 is attached. Reference gratings (for example, diffraction gratings) 52 having a periodic direction in the Y-axis direction are formed in the vicinity of one end and the other end in the longitudinal direction of the FD bar 46 in a symmetrical arrangement with respect to the center line LL. . A plurality of reference marks M are formed on the upper surface of the FD bar 46. As each reference mark M, a two-dimensional mark having a size detectable by an alignment system described later is used.

In the exposure apparatus 100 of the present embodiment, as shown in FIGS. 4 and 5, a straight line (hereinafter referred to as a reference axis) parallel to the Y axis connecting the optical axis AX of the projection optical system PL and the detection center of the primary alignment system AL1. A primary alignment system AL1 having a detection center is arranged at a position on the LV at a predetermined distance from the optical axis AX to the -Y side. Primary alignment system AL1 is fixed to the lower surface of the main frame (not shown). As shown in FIG. 5, secondary alignment systems AL2 ₁ and AL2 _{2 in} which detection centers are arranged almost symmetrically with respect to the reference axis LV on one side and the other side in the X-axis direction across the primary alignment system AL1. , AL2 ₃ and AL2 ₄ are provided. The secondary alignment systems AL2 _{1 to} AL2 ₄ are fixed to the lower surface of the main frame (not shown) via a movable support member, and the drive mechanisms 60 _{1 to} 60 ₄ (see FIG. 7) are used for the X-axis direction. The relative positions of these detection areas can be adjusted.

In the present embodiment, for example, an image processing type FIA (Field Image Alignment) system is used as each of the alignment systems AL1, AL2 _{1 to} AL2 ₄ . Imaging signals from each of the alignment systems AL1, AL2 _{1 to} AL2 ₄ are supplied to the main controller 20 via a signal processing system (not shown).

As shown in FIG. 3, interferometer system 118 irradiates reflecting surface 17a or 17b with an interferometer beam (length measuring beam), receives the reflected light, and positions wafer stage WST in the XY plane. Y interferometer 16, three X interferometers 126 to 128, and a pair of Z interferometers 43A and 43B. More specifically, the Y interferometer 16 reflects at least three length measuring beams parallel to the Y axis including a pair of length measuring beams B4 ₁ and B4 ₂ symmetric with respect to the reference axis LV, and a movable mirror 41 described later. Irradiate. Further, as shown in FIG. 3, the X interferometer 126 includes a pair of length measuring beams symmetrical with respect to a straight line (hereinafter referred to as a reference axis) LH parallel to the X axis orthogonal to the optical axis AX and the reference axis LV. B5 _1, B5 parallel measurement beam into at least three X-axis including ₂ irradiates the reflecting surface 17b. Further, the X interferometer 127 includes at least a length measuring beam B6 having a length measuring axis as a straight line LA (hereinafter referred to as a reference axis) LA parallel to the X axis orthogonal to the reference axis LV at the detection center of the alignment system AL1. A length measurement beam parallel to the two Y axes is irradiated onto the reflecting surface 17b. Further, the X interferometer 128 irradiates the reflection surface 17b with a measurement beam B7 parallel to the Y axis.

  Position information from each interferometer of the interferometer system 118 is supplied to the main controller 20. Based on the measurement results of Y interferometer 16 and X interferometer 126 or 127, main controller 20 adds rotation information (that is, pitching) in the θx direction in addition to the X and Y positions of wafer table WTB (wafer stage WST), The rotation information in the θy direction (that is, rolling) and the rotation information in the θz direction (that is, yawing) can also be calculated.

  As shown in FIG. 1, a movable mirror 41 having a concave reflecting surface is attached to the side surface on the −Y side of the stage main body 91. As can be seen from FIG. 2, the movable mirror 41 is longer in the X-axis direction than the reflecting surface 17a of the wafer table WTB.

  A pair of Z interferometers 43A and 43B that constitute part of the interferometer system 118 (see FIG. 7) are provided facing the movable mirror 41 (see FIGS. 1 and 3). Z interferometers 43A and 43B are connected to fixed mirrors 47A and 47B, for example, fixed to a frame (not shown) that supports projection unit PU, via movable mirror 41, and length measuring beams B1 and B2 parallel to the two Y axes, respectively. Irradiate B2. And each reflected light is received and the optical path length of length measuring beam B1, B2 is measured. Based on the result, main controller 20 calculates the position of wafer stage WST in the four degrees of freedom (Y, Z, θy, θz) direction.

  In the exposure apparatus 100 of the present embodiment, a plurality of encoder systems 150 are configured to measure the position (X, Y, θz) in the XY plane of the wafer stage WST independently of the interferometer system 118. A head unit is provided.

As shown in FIG. 4, four head units 62A, 62B, 62C, and 62D are arranged on the + X side, + Y side, -X side of the projection unit PU, and the -Y side of the primary alignment system AL1, respectively. ing. In addition, head units 62E and 62F are respectively provided on both outer sides in the X-axis direction of the alignment systems AL1, AL2 _{1 to} AL2 ₄ . The head units 62A to 62F are fixed in a suspended state to a main frame (not shown) that holds the projection unit PU via support members. In FIG. 4, symbol UP indicates an unloading position at which a wafer on wafer stage WST is unloaded, and symbol LP indicates a loading position at which a new wafer is loaded onto wafer stage WST. Show.

Head unit 62A, 62C, as shown in FIG. 5, Y heads 65 ₁ to 65 ₅ of the plurality which are arranged at predetermined intervals on the aforementioned reference axis LH (5 pieces here), Y heads 64 ₁ to 64 ₅ is provided. Hereinafter, if necessary, the Y heads 65 ₁ to 65 ₅ and Y heads 64 ₁ to 64 _5, respectively, will also be described as Y heads 65 and Y heads 64.

The head units 62A and 62C use the Y scales 39Y ₁ and 39Y ₂ to measure the position (Y position) of the wafer stage WST (wafer table WTB) in the Y-axis direction (multi-lens Y linear encoders 70A and 70C). 7). In the following, the Y linear encoder is abbreviated as “Y encoder” or “encoder” as appropriate.

As shown in FIG. 5, the head unit 62B is arranged on the + Y side of the projection unit PU, and includes a plurality of (here, four) X heads 66 _{5 to} 66 ₈ arranged on the reference axis LV at intervals WD. I have. Further, head unit 62D is arranged on the -Y side of primary alignment system AL1, a plurality which are arranged at a distance WD on reference axis LV (four in this case) and a X heads 66 ₁ to 66 _4. Hereinafter, the X heads 66 _{5 to} 66 ₈ and the X heads 66 _{1 to} 66 ₄ are also referred to as the X head 66 as necessary.

The head units 62B and 62D use the X scales 39X ₁ and 39X ₂ to measure the position (X position) of the wafer stage WST (wafer table WTB) in the X-axis direction (X position). 7). In the following, the X linear encoder is abbreviated as “X encoder” or “encoder” as appropriate.

Here, the interval WD in the X-axis direction of the five Y heads 65 and 64 (more precisely, the irradiation points on the scale of the measurement beam emitted by the Y heads 65 and 64) provided in the head units 62A and 62C, respectively. At the time of exposure or the like, it is determined that at least one head always faces the corresponding Y scales 39Y ₁ and 39Y ₂ (irradiates the measurement beam). Similarly, the interval WD in the Y-axis direction between adjacent X heads 66 (more precisely, the irradiation points on the scale of the measurement beam emitted by the X head 66) provided in the head units 62B and 62D is determined during exposure. , It is determined that at least one head always faces the corresponding X scale 39X or 39X ₂ (irradiates the measurement beam).

The distance between the most + Y side X heads 66 ₄ of the most -Y side of the X heads 66 ₅ and the head unit 62D of the head unit 62B is the movement of the Y-axis direction of wafer stage WST, between the two X heads The width of the wafer table WTB is set to be narrower than the width in the Y-axis direction so that it can be switched (connected).

Head unit 62E, as shown in FIG. 5, a Y heads _67i to 674 ₄ of the plurality of (four in this case).

Head unit 62F is equipped with a Y heads 68 ₁ to 68 ₄ of a plurality (four in this case). Y heads 68 ₁ to 68 _4, with respect to the reference axis LV, is disposed on the Y head 67 _{4-67 1} and symmetrical position. Hereinafter, if necessary, the Y head 67 _{4-67 1} and Y heads 68 ₁ to 68 _4, each describing both Y heads 67 and Y heads 68.

At the time of alignment measurement, at least one Y head 67 and 68 faces the Y scales 39Y ₂ and 39Y ₁ , respectively. The Y position (and θz rotation) of wafer stage WST is measured by Y heads 67 and 68 (that is, Y encoders 70E and 70F constituted by Y heads 67 and 68).

In the present embodiment, the Y heads 67 ₃ and 68 ₂ adjacent to the secondary alignment systems AL2 ₁ and AL2 ₄ in the X-axis direction are used as a pair of reference grids of the FD bar 46 when measuring the baseline of the secondary alignment system. The Y position of the FD bar 46 is measured at the position of each reference grating 52 by the Y heads 67 ₃ and 68 ₂ that face each other and the pair of reference gratings 52. Hereinafter, encoders configured by Y heads 67 ₃ and 68 ₂ respectively facing the pair of reference gratings 52 are referred to as Y linear encoders 70E ₂ and 70F ₂ (see FIG. 7). For identification purposes, Y encoders composed of Y heads 67 and 68 facing Y scales 39Y ₂ and 39Y ₁ are referred to as Y encoders 70E ₁ and 70F ₁ .

The measured values of the encoders 70A to 70F described above are supplied to the main controller 20. Main controller 20 determines position (X) of wafer stage WST in the XY plane based on the measured values of three of encoders 70A to 70D or three of encoders 70E ₁ , 7F ₁ , 70B and 70D. , Y, θz). Here, the measured values of X head 66 and Y heads 65 and 64 (or 68 and 67) (represented as C _X , C _Y1 and C _Y2 , respectively) are at the position (X, Y, θz) of wafer stage WST. On the other hand, it depends on the following expressions (1) to (3).

C _X = (p _X −X) cos θz + (q _X −Y) sin θz (1)
C _Y1 = − (p _Y1 −X) sin θz + (q _Y1 −Y) cos θz (2)
C _Y2 = − (p _Y2 −X) sin θz + (q _Y2 −Y) cos θz (3)
However, (p _X , q _X ), (p _{Y 1} , q _{Y 1} ), (p _{Y 2} , q _{Y 2} ) are X, 66, Y (or 68), and Y (or 67) X, 66, respectively. This is the Y installation position (more precisely, the X and Y positions of the irradiation point of the measurement beam). Therefore, main controller 20 substitutes measurement values C _X , C _Y1 , and C _Y2 of the three heads into simultaneous equations (1) to (3), and solves them to obtain them in the XY plane of wafer stage WST. The position (X, Y, θz) is calculated. According to this calculation result, drive control of wafer stage WST is performed.

Main controller 20 controls the rotation of FD bar 46 (wafer stage WST) in the θz direction based on the measurement values of linear encoders 70E ₂ and 70F ₂ . Here, the measured values of the linear encoders 70E and 70F (represented as C _Y1 and C _Y2 , respectively) are expressed by equations (2) and (3) with respect to the (X, Y, θz) position of the FD bar 46. Dependent. Accordingly, the θz position of the FD bar 46 is obtained from the measured values C _Y1 and C _{Y2 as in} the following equation (4).

sin θz = − (C _Y1 −C _Y2 ) / (p _Y1 −p _Y2 ) (4)
However, for the sake of simplicity, q _Y1 = q _Y2 is assumed.

  As each encoder head (Y head, X head), for example, an interference type encoder head disclosed in International Publication No. 2007/097379 pamphlet can be used. In this type of encoder head, two measurement beams are irradiated onto corresponding scales, the respective return lights are combined into one interference light, and the intensity of the interference light is measured using a photodetector. Based on the intensity change of the interference light, the displacement of the scale in the measurement direction (the diffraction grating periodic direction) is measured.

  Furthermore, in the exposure apparatus 100 of the present embodiment, as shown in FIGS. 4 and 6, a multipoint focal position detection system (hereinafter referred to as “multipoint AF system”) including an irradiation system 90a and a light receiving system 90b. ) Is provided. As the multipoint AF system, an oblique incidence system having the same configuration as that disclosed in, for example, US Pat. No. 5,448,332 is adopted. In the present embodiment, as an example, the irradiation system 90a is disposed on the + Y side of the −X end portion of the head unit 62E described above, and light is received on the + Y side of the + X end portion of the head unit 62F while facing this. A system 90b is arranged. The multipoint AF system (90a, 90b) is fixed to the lower surface of the main frame that holds the projection unit PU.

  In FIG. 4 and FIG. 6, a plurality of detection points irradiated with the detection beam are not shown individually, but as elongated detection areas (beam areas) AF extending in the X-axis direction between the irradiation system 90a and the light receiving system 90b. It is shown. Since the detection area AF is set to have a length in the X-axis direction that is approximately the same as the diameter of the wafer W, the wafer W is scanned almost in the Y-axis direction once in the Z-axis direction. Position information (surface position information) can be measured.

  As shown in FIG. 6, each pair of pairs constituting a part of the surface position measurement system 180 is arranged in the vicinity of both ends of the detection area AF of the multipoint AF system (90a, 90b) in a symmetrical arrangement with respect to the reference axis LV. Heads for Z position measurement (hereinafter abbreviated as “Z head”) 72a, 72b and 72c, 72d are provided. These Z heads 72a to 72d are fixed to the lower surface of a main frame (not shown).

As the Z heads 72a to 72d, for example, a head of an optical displacement sensor similar to an optical pickup used in a CD drive device or the like is used. Z heads 72a to 72d irradiate wafer table WTB with a measurement beam from above, receive the reflected light, and measure the surface position of wafer table WTB at the irradiation point. In the present embodiment, a configuration is adopted in which the measurement beam of the Z head is reflected by the reflection type diffraction grating constituting the Y scales 39Y ₁ and 39Y ₂ described above.

Further, as shown in FIG. 6, the head units 62A and 62C described above are in the same X position as the five Y heads 65 _j and 64 _i (i, j = 1 to 5) provided in the head units 62A and 62C. The five Z heads 76 _j and 74 _i (i, j = 1 to 5) are provided while being shifted. The five Z heads 76 _j and 74 _i belonging to the head units 62A and 62C are arranged symmetrically with respect to the reference axis LV. Incidentally, as each Z head 76 _j, 74 _i, the head of the same optical displacement sensor as described above for Z head 72a~72d is employed.

Above Z heads 72a to 72d, 74 to _72d, 76 ₁ to 76 _5, as shown in FIG. 7, are connected to the main controller 20 via the signal processing and selection device 170, the main control device 20, Z head 72a~72d via signal processing and selection device 170, and 74 to _72d, 76 ₁ to 76 operating condition by selecting any Z head from _five, and its operating state Surface position information detected by the Z head is received via the signal processing / selection device 170. In this embodiment, Z head _{72a~72d, 74 1 ~74 5, 76} 1 ~76 5 and the position information of the tilt direction and a signal processing and selection device 170 with respect to the Z-axis direction and the XY plane of wafer stage WST A surface position measurement system 180 is measured.

  In the present embodiment, main controller 20 uses surface position measurement system 180 (see FIG. 7), in an effective stroke area of wafer stage WST, that is, in an area where wafer stage WST moves for exposure and alignment measurement. The position coordinates in the two-degree-of-freedom direction (Z, θy) are measured.

At the time of exposure, main controller 20 determines a reference point (table surface and optical axis AX) on the table surface according to the measured value of at least one Z head 74 _i , 76 _j (i, j is any one of 1 to 5). The height Z ₀ and the rolling θy of wafer stage WST at the point of intersection) are calculated. Here, Z heads _{74 i, 76 j (i,} j is one of 1 to 5) measured values (respectively Z _L, denoted as Z _R), the wafer stage WST (Z _0, [theta] x, [theta] y) It depends on the position as shown in the following equations (5) and (6).

Z _L = −tan θy · p _L + tan θx · q _L + Z ₀ (5)
Z _R = −tan θy · p _R + tan θx · q _R + Z ₀ (6)
However, it is assumed that the upper surface of wafer table WTB including the scale surface is an ideal plane. Note that (p _L , q _L ) and (p _R , q _R ) are the X and Y installation positions of the Z heads 74 _i and 76 _j (more precisely, the X and Y positions of the irradiation point of the measurement beam), respectively. is there. From the equations (5) and (6), the following equations (7) and (8) are derived.

Z ₀ = [Z _L + Z _R −tan θx · (q _L + q _R )] / 2 (7)
tanθy = _{[Z L -Z R -tanθx · (q} L -q R) ] _{/ (p R -p L) ...} (8)
Therefore, main controller 20 calculates height Z ₀ and rolling θy of wafer stage WST from equations (7) and (8) using measured values Z _L and Z _R of Z heads 74 _i and 76 _j. To do. However, the pitching θx uses a measurement result of another sensor system (interferometer system 118 in the present embodiment).

The main controller 20 uses the measurement values (represented as Za, Zb, Zc, and Zd) of the four Z heads 72a to 72d at the time of focus calibration and focus mapping, and multipoint AF system (90a, 90b). The height Z ₀ and rolling θy of the wafer table WTB at the center (X, Y) = (Ox ′, Oy ′) of the plurality of detection points are calculated from the following equations (9) and (10).

Z ₀ = (Za + Zb + Zc + Zd) / 4 (9)
tanθy = - (Za + Zb- Zc-Zd) / (p a + p b -p c -p d) ... (10)
Here, (p _a , q _a ), (p _b , q _b ), (p _c , q _c ), and (p _d , q _d ) are the X and Y installation positions (more accurate) of the Z heads 72a to 72d, respectively. (X, Y position of the irradiation point of the measurement beam). _{However, p a = p b, p} c = p d, q a = q c, q b = q d, (p a + p c) / 2 = (p b + p d) / 2 = Ox ', (q a + Q _b ) / 2 = (q _c + q _d ) / 2 = Oy ′. As in the previous case, the pitching θx uses the measurement result of another sensor system (interferometer system 118 in the present embodiment).

  FIG. 7 shows the main configuration of the control system of the exposure apparatus 100. This control system is mainly configured of a main control device 20 composed of a microcomputer (or a workstation) for overall control of the entire apparatus.

  In the exposure apparatus of the present embodiment configured as described above, for example, a normal sequence using wafer stage WST according to a procedure similar to the procedure disclosed in the embodiment of International Publication No. 2007/097379. This process is executed by the main controller 20. This will be described later.

By the way, the diffraction gratings (innumerable grating lines 38 and 37 arranged at a predetermined pitch) constituting the Y scales 39Y ₁ and 39Y ₂ and the X scales 39X ₁ and 39X ₂ are thermally or mechanically used for a long time. It may be distorted by the action of a natural force. Even if such a distortion of the scale is minute, a measurement error that cannot necessarily be ignored can occur with respect to the measurement accuracy of the encoder system 150 (encoder head) required in the exposure apparatus 100 of the present embodiment. Further, the surface of the Y scales 39Y ₁ and 39Y ₂ (which constitutes the reflective diffraction grating) is not necessarily an ideal plane. Further, as described above, the Y scales 39Y ₁ and 39Y ₂ may be deformed over time. Such irregularities on the surface of the scale may cause a measurement error that cannot necessarily be ignored with respect to the measurement accuracy of the surface position measurement system 180 (Z head) required in the exposure apparatus 100.

  Therefore, in the present embodiment, the main controller 20 uses the interferometer system 118 to collect and create calibration information for correcting the measurement error of the encoder system 150, and uses it to measure the measurement error of the encoder system 150. Is corrected to ensure the accuracy of position measurement of wafer stage WST. Further, main controller 20 collects and creates calibration information for correcting the measurement error of surface position measurement system 180 using interferometer system 118, and uses it to measure the measurement error of surface position measurement system 180. The position measurement accuracy of wafer stage WST is ensured by correcting. This will be described below.

  Main controller 20 measures the X, Y, and θz positions of wafer stage WST using encoder system 150 according to the above-described procedure, and at the same time, determines the X, Y, and θz positions of wafer stage WST using interferometer system 118. measure. Here, the measurement results of the X, Y, and θz positions of the interferometer system 118 are expressed as ξ, ζ, and σ, respectively.

The main controller 20 collects calibration data ε _X (ε _X1 , ε _X2 ) in order to create calibration information for the X head 66. The position measurement results (ξ, ζ, σ) of wafer stage WST obtained using interferometer system 118 are substituted for X, Y, θz in equation (1), respectively, and measurement value C _X of X head 66 is used. Predict. The predicted measurement value C _X, referred to as gamma _X. Then, the difference epsilon _X = _C X-gamma _X of the measurement values _{C X} X heads 66 and its prediction value gamma _X, as calibration data, the irradiation of the measurement beams of X scales 39X ₁ or 39X on ₂ X heads 66 Collect for point location (x, y). However, X head ₆₆ 5-66 _8, i.e. X scales 39X difference collected for ₁ epsilon an _X epsilon _X1, X head ₆₆ 1-66 _4, i.e. X scales 39X difference epsilon _X collected for ₂ Is ε _X2 .

The calibration data ε _X mainly includes measurement errors of the encoder head due to scale distortion, but in principle, other measurement errors depending on the position of the irradiation point of the measurement beam on the scale are also captured.

The main controller 20, to create the calibration information for the Y heads 65 and 64, to collect calibration data epsilon _Y1, epsilon _Y2. Main controller 20 substitutes the position measurement results (ξ, ζ, σ) of wafer stage WST obtained using interferometer system 118 for X, Y, θz in equations (2) and (3), respectively. The measured values C _Y1 and C _Y2 of the Y heads 65 and 64 are predicted. The predicted measurement values C _Y1 and C _Y2 are denoted as Γ _Y1 and Γ _Y2 , respectively. Then, the main controller 20, Y measurement values _{C Y1, C Y2} and their predicted value gamma _Y1 heads 65 and 64, gamma _Y2 difference between _{ε Y1 = C Y1 -Γ Y1,} ε Y2 = C Y2 -Γ _Y2 is collected as calibration data for the positions (x, y) of the measurement beam irradiation points of the Y heads 65 and 64 on the Y scales 39Y ₁ and 39Y ₂ , respectively.

Main controller 20 also collects calibration data ε _Y1 and ε _Y2 for creating calibration information for Y heads 68 and 67 in the same manner as those for Y heads 65 and 64.

Main controller 20 collects calibration data ε _X1 , ε _X2 , ε _Y1 , and ε _Y2 during execution of a normal sequence process described later of exposure apparatus 100, that is, in parallel with processes such as an exposure process and an alignment process. ,Execute. Here, as shown in FIG. 8A, when collection is performed in parallel with the exposure process, calibration data for the X head 66 and the Y heads 65 and 64 used during the exposure process is collected. The In the situation shown in FIG. 8 (A), the calibration data for the X heads 66 ₅ and Y heads ₆₅ 3, 64 ₃ are collected. In addition, as shown in FIG. 8B, when collection is performed in parallel with the alignment process, calibration data for the X head 66 and the Y heads 68 and 67 used during the alignment measurement process is collected. The In the situation shown in FIG. 8 (B), the calibration data for the X heads 66 ₂ and Y head ₆₇ 3, 68 ₂ are collected.

  Main controller 20 measures the Z and θy positions of wafer stage WST using surface position measurement system 180 in accordance with the above-described procedure, and at the same time uses Z and θy positions of wafer stage WST using interferometer system 118. The θx position is measured. Here, the measurement results of the Z, θy, and θx positions of the interferometer system 118 are expressed as η, σy, and σx, respectively.

The main controller 20, Z head 76,72C, to create the calibration information for 72d, collecting calibration data epsilon _Z1. Main controller 20 substitutes the position measurement results (η, σy, σx) of wafer stage WST obtained by using interferometer system 118 for Z ₀ , θy, θx in equation (6), respectively, and the Z head The measured values Z _R of 76, 72c, 72d are predicted. The predicted measurement value Z _R is expressed as Γ _Z1 . The main controller 20 then uses the difference ε _Z1 = Z _R −Γ _Z1 between the measured value Z _R of the Z heads 76, 72c, and 72d and the predicted value Γ _Z1 as calibration data, Z on the Y scale 39Y _1. Data are collected for the positions (x, y) of the irradiation points of the measurement beams of the heads 76, 72c, 72d.

The main controller 20, as above, to create the calibration information for the Z head 74,72A, 72b, collecting calibration data epsilon _Z2. Main controller 20 substitutes the position measurement results (η, σy, σx) of wafer stage WST obtained by using interferometer system 118 for Z ₀ , θy, θx in equation (5), respectively, and the Z head The measured values Z _L of 74, 72a, 72b are predicted. The predicted measurement value Z _L, referred to as gamma _Z2. Then, main controller 20 uses the difference ε _Z2 = Z _R −Γ _Z2 between measured value Z _L of Z heads 74, 72a, and 72b and its predicted value Γ _Z2 as calibration data, Z on Y scale 39Y _2. Data are collected for the positions (x, y) of the irradiation points of the measurement beams of the heads 74, 72a, 72b.

The calibration data ε _Z1 and ε _Z2 mainly incorporate measurement errors of the Z head due to the irregularities on the surface of the scale, but in principle, other measurements depending on the position of the irradiation point of the measurement beam on the scale. Errors are also included.

Main controller 20 collects calibration data ε _Z1 and ε _Z2 while the exposure apparatus is in operation, that is, in parallel with processing such as exposure process and focus mapping (and focus calibration). Here, as shown in FIG. 8A, when collection is executed in parallel with the exposure process, calibration data for the Z heads 76 and 74 used during the exposure process is collected. In the situation shown in FIG. 8A, calibration data for the Z heads 76 ₃ and 74 ₃ is collected. In addition, as shown in FIG. 9, when acquisition is performed in parallel with focus mapping (and focus calibration), calibration data for the Z heads 72a to 72d used during these processes is collected.

  Main controller 20 is not limited to the actual exposure operation, and calibration is performed on X head 66 and Y heads 65 and 64 when wafer stage WST is located in an area where wafer stage WST moves during the exposure operation. Data and calibration data for the Z heads 76, 74 may be collected. Further, main controller 20 is not limited to the actual alignment measurement, and calibration is performed on X head 66 and Y heads 65 and 64 when wafer stage WST is located in an area where wafer stage WST moves during alignment measurement. Data may be collected. The main controller 20 is not limited to the actual focus mapping (and focus calibration), and when the wafer stage WST is located in the area where the wafer stage WST moves during these processes, Calibration data for 72d may be collected.

  In addition, main controller 20 selects and collects calibration data in order to create highly accurate calibration information. For example, if there are features in scale distortion and irregularities, an appropriate model is assumed to reproduce them. An amount corresponding to the calibration data ε estimated from this model is expressed as ε ′. The main controller 20 collects more calibration data ε than the other regions in the region on the scale where the difference ε−ε ′ between the collected calibration data ε and the corresponding model ε ′ is large. Alternatively, the main controller 20 collects more calibration data than the other regions in the region on the scale where the change with respect to the position (x, y) of the difference ε−ε ′ is significant.

  Main controller 20 stops collecting calibration data when the acceleration of wafer stage WST exceeds a predetermined allowable range. This is because the scale is distorted as the wafer stage WST is accelerated, which causes an encoder measurement error. In the present embodiment, the interferometer system 118 is used as a reference measurement system for calibrating the encoder system 150 and the surface position measurement system 180. Here, in the measurement using the interferometer, a measurement error may occur due to air fluctuations caused by the temperature change and temperature gradient of the atmosphere on the optical path of the measurement beam. Therefore, main controller 20 interrupts the collection of calibration data when the speed of wafer stage WST exceeds a range where measurement errors due to air fluctuations do not occur or are sufficiently negligible. Further, it is desirable that main controller 20 collects calibration data only when wafer stage WST maintains the reference posture (θx = θy = 0).

  In addition, it is necessary to collect a sufficient number of calibration data with no bias over the entire area on the scale. Therefore, main controller 20 suspends collection of calibration data when wafer stage WST is stopped or when it is apparent that the wafer stage WST moves only within a partial region. These situations can occur when an abnormality occurs and the exposure apparatus stops urgently. Therefore, the collection of calibration data may be interrupted at the operator's discretion.

The main controller 20 uses the calibration data ε (ε _X1 , ε _X2 , ε _Y1 , ε _Y2 ) collected according to the above-described procedure, to each of the heads 66, 65, 64, 68, 67 constituting the encoder system 150. Calibration information for correcting the measurement error is created. Here, a trial function ΔC (x, y) that is a function of the x, y position on the scale (x, y position of the irradiation point of the measurement beam) is given to the calibration information. Here, the trial functions are expressed as ΔC _X1 , ΔC _X2 , ΔC _Y1 , and ΔC _Y2 corresponding to the X scales 39X ₁ and 39X ₂ and the Y scales 39Y ₁ and 39Y ₂ , respectively. For example, a linear function ΔC (x, y) = a + bx + cy is given as a trial function. The main controller 20 determines the least squares of the undetermined multipliers a, b, and c included in the trial function using the collected calibration data ε. That is, the minimum square error _{S = Σ i = 1~N | ε} i -ΔC (x i, y i) | w i determines undetermined multipliers a to assume a minimum value, b, or c. However, it was assumed that N positions _x i, calibration data epsilon _i for _{y i} is collected. W _i is a weight for the calibration data ε _i .

Here, the x, y position of the irradiation point of the measurement beam on the scale is converted from the position (X, Y, θz) of wafer stage WST measured using encoder system 150. Alternatively, it may be converted from the position (ξ, ζ, σ) of wafer stage WST measured using interferometer system 118. However, in any case, the converted x and y positions include measurement errors. Therefore, the weights _{w i} in the minimum square error S described above, for example ^{_{w i = σ i 2 + b}} 2 σ xi 2 + c 2 σ yi 2 and may provide. _{However, σ i, σ xi, σ} yi is, ε _{i, x i,} is the standard deviation of the _{y i.}

Further, main controller 20, the calibration data ε (ε _Z1, ε _Z2) collected according to the procedure described above using the measurement error of each Z head 76,74,72a~72d constituting the surface position measurement system 180 Create calibration information to correct Here, a trial function ΔZ (x, y) which is a function of the x, y position on the scale (x, y position of the irradiation point of the measurement beam emitted by the Z head) is given to the calibration information. Here, trial functions for the Y scales 39Y ₁ and 39Y ₂ are expressed as ΔZ ₁ and ΔZ ₂ , respectively. As a trial function, for example, a linear function ΔZ (x, y) = a + bx + cy is given. The main controller 20 determines the least squares of the undetermined multipliers a, b, and c included in the trial function using the collected calibration data ε. That is, the minimum square error _{S = Σ i = 1~N | ε} i -ΔZ (x i, y i) | w i determines undetermined multipliers a to assume a minimum value, b, or c. However, it was assumed that N positions _x i, calibration data epsilon _i for _{y i} is collected. W _i is a weight for the calibration data ε _i .

Then, when driving wafer stage WST, main controller 20 uses, for example, the created calibration information ΔC _X1 (x, y) to obtain measurement information C _X1 of X heads 66 _{5 to} 66 ₈ as <C _X1 > = C _X1 −ΔC _X1 (x, y) is corrected. Here, x, y is the position of the irradiation point of measurement beams of X scales 39X ₁ on X head ₆₆ 5-66 _8. Measurement information <C _X1 > or <C _X2 >, <C _Y1 >, <C _Y2 > of each head corrected in this way is used as C _X , C _Y1 , C in simultaneous equations (1) to (3). _By substituting into _Y2 and solving the equation, the position (X, Y, θz) of wafer stage WST in the XY plane is calculated. According to this calculation result, drive control of wafer stage WST is performed.

Further, when driving wafer stage WST, main controller 20 uses measurement information Z _R of Z heads 76, 72c, and 72d to be <Z _R > using the created calibration information ΔZ ₁ (x, y). = Z _R −ΔZ ₁ (x, y) Here, x and y are the positions of the measurement beam irradiation points of the Z heads 76, 72c and 72d on the Y scale 39Y ₁ . Similarly, using the created calibration information ΔZ ₂ (x, y), the measurement information Z _L of the Z heads 74, 72a, 72b is corrected as <Z _L > = Z _L −ΔZ ₂ (x, y). To do. Here, x, y is, Y scales 39Y ₂ on the Z head 74,72A, a position of the irradiation point of 72b of the measurement beam. The measurement information <Z _R >, <Z _L > of each head corrected in this way is substituted into Z _R , Z _L in equations (7), (8), and the Z, θy positions of wafer stage WST Is calculated. For Z heads 72a to 72d, Z and θy positions of wafer stage WST are calculated by substituting for Za to Zd in equations (9) and (10). According to this calculation result, drive control of wafer stage WST is performed.

In the exposure apparatus 100 of the present embodiment, for example, every time a predetermined number of wafers are exposed and the last wafer is replaced, calibration information ΔC (ΔC _X1 , ΔC _X2 , ΔC _Y1 , ΔC _Y2 ) according to the above-described procedure. And / or the calibration information ΔZ (ΔZ ₁ , ΔZ ₂ ) is updated. For example, the predetermined number is set to 1 or 25 (1 lot). Furthermore, when generating calibration information, only calibration data ε (ε _X1 , ε _X2 , ε _Y1 , ε _Y2 ) and / or ε (ε _Z1 , ε _Z2 ) within a certain time after collection are used. To do. Then, the undetermined multiplier included in the trial function is determined as the least square, and the calibration information ΔC and / or ΔZ is updated only when a certain determination accuracy is obtained. As described above, by appropriately updating the calibration information, the measurement error of the encoder system 150 and / or the surface position measurement system 180 and even the measurement error that expands with time can be eliminated. Highly accurate and stable drive control of wafer stage WST becomes possible.

The calibration information ΔC _X1 may be created as common information used for the X heads 66 _{5 to} 66 ₈ facing the X scale 39X ₁ . Similarly, calibration information [Delta] C _X2, [Delta] C _Y1, and [Delta] C _Y2, respectively, X scales 39X _2, Y scales 39Y _1, and X head ₆₆ facing the _{39Y 2} 1 ~66 4, Y heads 65, 68 and 64, , 67 may be created as common information. Further, calibration information [Delta] Z _1, [Delta] Z _2, respectively, may be created as a common information used for Z heads 76 and 74 that face Y scales 39Y _1, 39Y _2.

  Further, during the exposure process and the alignment measurement process, wafer stage WST moves on a fixed trajectory unless an abnormality occurs. Therefore, the area on the scale where each head irradiates the measurement beam is limited to a part of the area. Therefore, the calibration information may be created as individual information used for each head. However, in this process, continuity between calibration information for individual heads may be impaired. In that case, continuity between the calibration information may be ensured by adding an offset to the calibration information for one of the heads to be switched based on the calibration information at the position of wafer stage WST for switching the head to be used. .

  Further, in order to create more accurate calibration information, a second or higher order trial function ΔC (x, y) or ΔZ (x, y) may be used. In this case, the calibration information is created as common information used for all the heads facing one scale. However, it is a condition that the continuity of the calibration data ε obtained using all the heads is sufficiently guaranteed for all the areas on the scale.

  Here, a normal sequence process using wafer stage WST executed by main controller 20 will be described.

  When the wafer stage WST is at the unloading position UP (see FIG. 4), the wafer W is unloaded, and when moved to the loading position LP (see FIG. 4), a new wafer W is loaded onto the wafer table WTB. Is done. In the vicinity of the unloading position UP and loading position LP, the position of wafer stage WST with six degrees of freedom is controlled based on the measurement value of interferometer system 118. At this time, the X interferometer 128 is used.

  After the loading is completed, the first stage of baseline check of the prime alignment system AL1 is performed in which the wafer stage WST is moved and the reference mark FM of the measurement plate 30 is detected by the primary alignment system AL1. Around this time, the origin of the encoder system and interferometer system is reset (reset).

Thereafter, a plurality of sample shots on the wafer W are measured using the alignment systems AL1, AL2 _{1 to} AL2 ₄ while measuring the position of the wafer stage WST in the six degrees of freedom direction using the encoder system 150 and the Z heads 72a to 72d. Alignment measurement for detecting the alignment mark of the region is executed, and in parallel with this, focus mapping (the surface of the wafer W with reference to the measurement values of the Z heads 72a to 72d) using the multipoint AF system (90a, 90b) is performed. Measurement of position (Z position) information) is performed. When the measurement plate 30 reaches just below the projection optical system PL during the movement of the wafer stage WST for alignment measurement and focus mapping in the + Y direction, the reticle R is used by using the aerial image measurement devices 45A and 45B. The latter half of the baseline check of the primary alignment system AL1 is performed to measure the upper pair of alignment marks by the slit scan method.

  Thereafter, alignment measurement and focus mapping are continued.

  When the alignment measurement and focus mapping are completed, the step-and-scan method on the wafer W is performed based on the position information of each shot area on the wafer obtained as a result of the alignment measurement and the latest baseline of the alignment system. A plurality of shot areas are exposed, and a reticle pattern is transferred. During the exposure operation, focus leveling control of the wafer W is performed based on information obtained by focus mapping. The Z and θy of the wafer being exposed are controlled based on the measured values of the Z heads 74 and 76, while θx is controlled based on the measured values of the Y interferometer 16.

In addition, the baseline measurement of the secondary alignment systems AL2 _{1 to} AL2 ₄ is performed at the appropriate timing with the measurement values of the encoders 70E ₂ and 70F ₂ described above, as in the method disclosed in International Publication No. 2007/097379. Based on the adjustment of the θz rotation of the FD bar 46 (wafer stage WST), the reference marks M on the FD bar 46 in the respective fields of view are simultaneously measured using the alignment systems AL1, AL2 _{1 to} AL2 _4. It is done by doing.

  As described above, a series of processes using wafer stage WST is performed.

  As described above in detail, in the exposure apparatus 100 of the present embodiment, the main controller 20 measures the position information of the wafer stage WST using the encoder system 150 and the surface position measurement system 180, and each encoder head. The deviation ε of the measurement information C from the reference information Γ corresponding thereto and the deviation ε of the individual head measurement information Z from the reference information Γ corresponding thereto are collected. Then, main controller 20 uses the collected deviation ε to create calibration information ΔC and ΔZ for correcting measurement errors of the individual encoder heads and Z heads. Then, when driving wafer stage WST, main controller 20 corrects position information of wafer stage WST measured using the created calibration information ΔC and ΔZ, and moves wafer stage WST according to the corrected position information. To drive. As a result, highly accurate drive control of wafer stage WST is possible.

  Further, main controller 20 collects deviation ε for creating calibration information ΔC in parallel with at least one of the exposure process and the alignment measurement process. Further, main controller 20 collects deviation ε for creating calibration information ΔZ in parallel with at least one of the exposure operation and focus mapping (and focus calibration). As a result, it is possible to maintain highly accurate drive control of wafer stage WST without reducing throughput, and to calibrate measurement errors that can be enlarged or reduced during operation of the exposure apparatus.

  In the exposure apparatus 100 of the present embodiment, the position information of the wafer stage WST is measured using a reference measurement system, and the measurement information C of each encoder head and the measurement information Z of the Z head are predicted from the measurement information. The deviation ε of the measurement information C of each encoder head from the predicted measurement information Γ and the deviation ε of the measurement information of each Z head from the predicted measurement information Γ are determined as the positions of the irradiation points of the measurement beams on the scale. Collect against. Then, main controller 20 uses calibration information ΔC for correcting position information measured using encoder system 150 and position measured using surface position measurement system 180 using collected deviation ε. Calibration information calibration information ΔZ for correcting information is created. Therefore, it is possible to create calibration information for correcting measurement errors caused by scale distortion (and measurement errors depending on the position of the irradiation point of the measurement beam on the scale as well). Then, when driving wafer stage WST, position information of wafer stage WST measured using encoder system 150 and surface position measurement system 180 is corrected using the created calibration information, and according to the corrected position information. Wafer stage WST can be driven. As a result, highly accurate drive control of wafer stage WST is possible.

  In this embodiment, interferometer system 118 is adopted as a reference measurement system, and measurement information of individual encoder heads and Z heads predicted from position information of wafer stage WST measured using interferometer system 118 is obtained. Used as reference information. Here, in the measurement using the interferometer, as described above, a measurement error due to air fluctuation may occur. However, by selecting and collecting calibration data as in this embodiment, it is possible to collect only good quality calibration data that does not include measurement errors or includes small errors. Further, by creating calibration information as in the present embodiment, measurement errors that can be included in the calibration data are averaged, so that highly accurate calibration information can be created.

  Note that the configuration of each measuring apparatus such as the encoder system described in the above embodiment is merely an example, and the present invention is of course not limited thereto. For example, in the above-described embodiment, an encoder system having a configuration in which a lattice unit (Y scale, X scale) is provided on a wafer table (wafer stage), and an X head and a Y head are arranged outside the wafer stage so as to face the lattice unit. Although the case where it is adopted is illustrated, the present invention is not limited to this, and as disclosed in, for example, US Patent Application Publication No. 2006/0227309, an encoder head is provided on the wafer stage, and the wafer stage is opposed to the encoder head. You may employ | adopt the encoder system of the structure which arrange | positions a grating | lattice part (For example, the two-dimensional grating | lattice or the two-dimensionally arranged one-dimensional grating | lattice part) outside. In this case, the Z head may also be provided on the wafer stage, and the surface of the lattice portion may be a reflective surface to which the Z head measurement beam is irradiated.

  In the above-described embodiment, for example, the case where the encoder head and the Z head are separately provided in the head units 62A and 62C has been described. However, a single unit having the functions of the encoder head and the Z head has been described. The head may be used in place of a set of encoder head and Z head.

  In the above-described embodiment, the case where the present invention is applied to a dry type exposure apparatus that exposes the wafer W without using liquid (water) has been described. No. 99/49504, European Patent Application No. 1420298, International Publication No. 2004/055803 Pamphlet, Japanese Patent Application Laid-Open No. 2004-289126 (corresponding US Pat. No. 6,952,253), and the like. An exposure apparatus that forms an immersion space including an optical path of illumination light between the projection optical system and the wafer, and exposes the wafer with illumination light through the liquid in the projection optical system and the immersion space. The present invention can be applied. Further, the present invention can also be applied to an immersion exposure apparatus disclosed in, for example, International Publication No. 2007/097379 pamphlet (corresponding to US Patent Application Publication No. 2008/088843). In the immersion exposure apparatus disclosed in the pamphlet of International Publication No. 2007/097379 (corresponding to US Patent Application Publication No. 2008/088843), a grating (scale) provided on a wafer stage is irradiated with a measurement beam, An encoder system that measures the relative position between the head and the scale in the periodic direction of the grating by receiving the reflected light is employed. For this reason, the immersion area formed by the immersion liquid (liquid) may cover the scale. At this time, heat transfer occurs between the immersion liquid (liquid) and the scale, and thermal stress can be applied to the scale. Therefore, it is conceivable that the distortion of the scale expands or contracts during operation of the exposure apparatus. Therefore, as described in the above embodiment, the present invention, in which the above-described deviation is collected and calibration information is created during the sequence of a normal exposure apparatus, can be applied particularly preferably. it can.

  In the above embodiment, the case where the present invention is applied to a scanning exposure apparatus such as a step-and-scan method has been described. However, the present invention is not limited to this, and the present invention is applied to a stationary exposure apparatus such as a stepper. May be. Even in the case of a stepper or the like, the same effect can be obtained because the position of the stage on which the object to be exposed is mounted can be measured using the encoder as in the above embodiment. The present invention can also be applied to a step-and-stitch reduction projection exposure apparatus, a proximity exposure apparatus, or a mirror projection aligner that synthesizes a shot area and a shot area. Further, as disclosed in, for example, US Pat. No. 6,590,634, US Pat. No. 5,969,441, US Pat. No. 6,208,407, etc. The present invention can also be applied to a multi-stage type exposure apparatus provided with a stage. Further, as disclosed in, for example, WO 2005/074014 pamphlet, an exposure apparatus including a measurement stage including a measurement member (for example, a reference mark and / or a sensor) is provided separately from the wafer stage. The present invention is applicable.

  Further, the projection optical system in the exposure apparatus of the above embodiment may be not only a reduction system but also any of the same magnification and enlargement systems, and the projection optical system PL may be any of a reflection system and a catadioptric system as well as a refraction system. The projected image may be either an inverted image or an erect image. In addition, the illumination area and the exposure area described above are rectangular in shape, but are not limited thereto, and may be, for example, an arc, a trapezoid, or a parallelogram.

The light source of the exposure apparatus of the above embodiment is not limited to the ArF excimer laser, but is a KrF excimer laser (output wavelength 248 nm), F ₂ laser (output wavelength 157 nm), Ar ₂ laser (output wavelength 126 nm), Kr ₂ laser ( It is also possible to use a pulse laser light source with an output wavelength of 146 nm, an ultrahigh pressure mercury lamp that emits a bright line such as g-line (wavelength 436 nm), i-line (wavelength 365 nm), and the like. A harmonic generator of a YAG laser or the like can also be used. In addition, as disclosed in, for example, U.S. Pat. No. 7,023,610, a single wavelength laser beam in an infrared region or a visible region oscillated from a DFB semiconductor laser or a fiber laser as vacuum ultraviolet light, For example, a harmonic which is amplified by a fiber amplifier doped with erbium (or both erbium and ytterbium) and wavelength-converted into ultraviolet light using a nonlinear optical crystal may be used.

  In the above embodiment, it is needless to say that the illumination light IL of the exposure apparatus is not limited to light having a wavelength of 100 nm or more, and light having a wavelength of less than 100 nm may be used. For example, in recent years, in order to expose a pattern of 70 nm or less, EUV (Extreme Ultraviolet) light in a soft X-ray region (for example, a wavelength region of 5 to 15 nm) is generated using an SOR or a plasma laser as a light source, and its exposure wavelength Development of an EUV exposure apparatus using an all-reflection reduction optical system designed under (for example, 13.5 nm) and a reflective mask is underway. In this apparatus, a configuration in which scanning exposure is performed by synchronously scanning a mask and a wafer using arc illumination is conceivable, and therefore the present invention can be suitably applied to such an apparatus. In addition, the present invention can be applied to an exposure apparatus using a charged particle beam such as an electron beam or an ion beam.

  In the above-described embodiment, a light transmission mask (reticle) in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. Instead of this reticle, For example, as disclosed in US Pat. No. 6,778,257, an electronic mask (variable shaping mask, which forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed, as disclosed in US Pat. No. 6,778,257. For example, a non-light emitting image display element (spatial light modulator) including a DMD (Digital Micro-mirror Device) may be used.

  Further, for example, the present invention can be applied to an exposure apparatus (lithography system) that forms line and space patterns on a wafer by forming interference fringes on the wafer.

  Further, as disclosed in, for example, US Pat. No. 6,611,316, two reticle patterns are synthesized on a wafer via a projection optical system, and one scan exposure is performed on one wafer. The present invention can also be applied to an exposure apparatus that performs double exposure of shot areas almost simultaneously.

  Note that the object on which the pattern is to be formed in the above embodiment (the object to be exposed to the energy beam) is not limited to the wafer, but other objects such as a glass plate, a ceramic substrate, a film member, or a mask blank. But it ’s okay.

  The use of the exposure apparatus is not limited to the exposure apparatus for semiconductor manufacturing. For example, an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern onto a square glass plate, an organic EL, a thin film magnetic head, an image sensor ( CCDs, etc.), micromachines, DNA chips and the like can also be widely applied to exposure apparatuses. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., glass substrates or silicon wafers, etc. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern.

  An electronic device such as a semiconductor element includes a step of designing a function / performance of the device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and the exposure apparatus (pattern forming apparatus) of the above-described embodiment. ) A lithography step for transferring a mask (reticle) pattern onto a wafer, a development step for developing the exposed wafer, an etching step for removing exposed members other than the portion where the resist remains by etching, and etching is completed. It is manufactured through a resist removal step for removing unnecessary resist, a device assembly step (including a dicing process, a bonding process, and a package process), an inspection step, and the like. In this case, in the lithography step, the exposure method described above is executed using the exposure apparatus of the above embodiment, and a device pattern is formed on the wafer. Therefore, a highly integrated device can be manufactured with high productivity.

  The exposure method and apparatus of the present invention are suitable for forming a pattern on an object. The device manufacturing method of the present invention is suitable for manufacturing an electronic device such as a semiconductor element or a liquid crystal display element.

It is a figure which shows schematically the structure of the exposure apparatus of one Embodiment. It is a top view which shows a wafer stage. It is a top view which shows arrangement | positioning of the stage apparatus with which the exposure apparatus of FIG. 1 is equipped, and an interferometer. It is a top view which shows arrangement | positioning of the stage apparatus and sensor unit with which the exposure apparatus of FIG. 1 is provided. It is a top view which shows arrangement | positioning of an encoder head (X head, Y head) and an alignment system. It is a top view which shows arrangement | positioning of Z head and a multipoint AF system. It is a block diagram which shows the main structures of the control system of the exposure apparatus of one Embodiment. FIG. 8A shows the wafer stage position measurement and calibration data collection using the encoder during the exposure process, and FIG. 8B shows the wafer stage position measurement and calibration data collection using the encoder during the alignment measurement. It is a figure for demonstrating. It is a figure for demonstrating the position measurement of a wafer stage using Z head in focus mapping and focus calibration, and collection of calibration data.

Explanation of symbols

10 ... illumination system 20 ... main control unit, 39X _1, 39X ₂ ... X scales 39Y _1, 39Y ₂ ... Y scale, 50 ... stage device, 62a to 62f ... head unit, 64 and 65 ... Y head, 66 ... X head, 67, 68 ... Y head, 70A, 70C ... Y encoder, 70B, 70D ... X encoder, 72a to 72d, 74, 76 ... Z head, 100 ... Exposure apparatus, 118 ... Interferometer system, 124 ... Stage drive 150, encoder system, 180, surface position measurement system, PL, projection optical system, PU, projection unit, RST, reticle stage, R, reticle, W, wafer, WST, wafer stage, WTB, wafer table.

Claims (54)

An exposure method for forming a pattern on an object,
Using at least one head provided on one of a moving body that moves within a predetermined plane and the outside of the moving body, measurement light is applied to a measurement surface provided on the other of the moving body and the outside of the moving body. , Receiving light from the measurement surface, measuring position information of the moving body, and driving the moving body according to the position information;
Forming a pattern on the object held by the moving body;
Detecting a mark applied to the object;
Collecting the deviation of the position information from the reference information corresponding to the position information in parallel with at least one of the forming step and the detecting step.   The exposure method according to claim 1, wherein in the collecting step, the deviation is collected with respect to a position of an irradiation point of the measurement light on the measurement surface. Assuming a model for the deviation,
3. The exposure method according to claim 2, wherein, in the collecting step, for the region on the measurement surface where the difference between the displacement and the model is large, a larger amount of the displacement than the region on the measurement surface outside the region is collected. . Assuming a model for the deviation,
3. The collection step according to claim 2, wherein in the region on the measurement surface where the difference between the displacement and the model is significant, the displacement is collected more than the region on the measurement surface outside the region. Exposure method.   The exposure method according to any one of claims 1 to 4, wherein in the collecting step, the collection of the deviation is interrupted when at least one of acceleration and speed of the moving body exceeds an allowable range.   The exposure method according to any one of claims 1 to 5, wherein in the collecting step, the collection of the deviation is interrupted when the moving body is stopped.   The collecting step interrupts the collection of the deviation when it is clear that the moving body moves only in a partial region within the predetermined plane. An exposure method according to 1.   The exposure method according to claim 6 or 7, wherein in the collecting step, the collection of the shift is artificially interrupted.   The exposure method according to any one of claims 1 to 8, wherein the collecting step is executed only when the movable body maintains a reference posture.   The exposure method according to claim 1, wherein the collecting step is executed when the moving body is located in a region where the moving body moves during the forming step.   The exposure method according to any one of claims 1 to 10, wherein the collecting step is executed when the moving body is located in a region in which the moving body moves during the detecting step.   The exposure method according to any one of claims 1 to 11, further comprising a step of creating calibration information for correcting the position information using the deviation collected in the collecting step.   The exposure method according to claim 12, wherein, in the creating step, only the deviation within a predetermined time after the collection is used among the collected deviations.   The exposure method according to claim 12 or 13, wherein the creating step is executed every time a pattern is formed on a predetermined number of the objects.   The exposure method according to claim 12, wherein the creating step is executed only when a certain accuracy is guaranteed for the calibration information.   16. The driving step corrects the position information using the calibration information created in the creating step, and drives the moving body according to the corrected position information. An exposure method according to 1. Measuring the position information of the movable body using an interferometer system independent of the head, and further predicting the position information measured using the head from the position information,
The exposure method according to claim 1, wherein the position information predicted in the prediction step is the reference information. An exposure method for forming a pattern on an object,
Using at least one head provided on one of a moving body that moves within a predetermined plane and the outside of the moving body, measurement light is applied to a measurement surface provided on the other of the moving body and the outside of the moving body. , Receiving light from the measurement surface, measuring position information of the moving body, and driving the moving body according to the position information and calibration information for correcting the position information;
Forming a pattern on the object held by the moving body;
Detecting a mark applied to the object;
In parallel with at least one of the forming step and the detecting step, the position information of the moving body is measured using a reference measurement system, and the measurement information of the head is predicted from the measurement information of the reference measurement system. Collecting a deviation of measurement information of the head from the measurement information with respect to a position of an irradiation point of the measurement light on the measurement surface;
Creating the calibration information using the deviation collected in the collecting step. The calibration information is expressed using a trial function that is a function of the position of the irradiation point of the measurement light on the measurement surface,
19. The exposure method according to claim 18, wherein, in the creating step, the calibration information is created by determining an undetermined multiplier included in the trial function by using the collected deviation and least squares.   The exposure method according to claim 19, wherein the trial function is given as a linear function with respect to the position of the irradiation point. In the step of driving, when measuring the position information of the moving body, a plurality of the heads are used,
21. The exposure method according to claim 18, wherein, in the creating step, the calibration information is created as common information used for all of the plurality of heads. In the step of driving, when measuring the position information of the moving body, a plurality of the heads are used,
21. The exposure method according to any one of claims 18 to 20, wherein in the creating step, the calibration information is created as individual information used for each of the plurality of heads.   23. The individual information is created using a deviation of the position information measured using one of the plurality of heads corresponding to the information from the predicted position information. The exposure method as described. In the step of driving, when measuring the position information of the moving body, a plurality of the heads are used,
When the continuity of deviation from the predicted position information of the position information measured using the plurality of heads is ensured, the trial function is set to a second or higher order higher order with respect to the position of the irradiation point. The exposure method according to claim 19, which is given as a function.   The exposure method according to any one of claims 18 to 24, wherein in the driving step, the position information is corrected using the calibration information, and the movable body is driven according to the corrected position information.   The exposure method according to any one of claims 18 to 25, wherein the reference measurement system is an interferometer system including a plurality of interferometers. The measurement surface has a grating whose periodic direction is at least one axial direction in the predetermined plane,
The exposure method according to any one of claims 18 to 26, wherein the head uses the periodic direction as a measurement direction.   27. The exposure method according to any one of claims 18 to 26, wherein the head has a direction perpendicular to the predetermined plane as a measurement direction.   The exposure method according to any one of claims 1 to 28, wherein, in the forming step, the sensitive layer of the object is irradiated with an energy beam to form the pattern.   30. The exposure method according to claim 29, wherein the energy beam is irradiated through an optical system and a liquid supplied between the optical system and the object. A step of forming a pattern on the object using the exposure method according to claim 1;
And a step of processing the object on which the pattern is formed. An exposure apparatus that forms a pattern on an object,
A moving body that holds the object and moves in a predetermined plane;
The measurement surface is provided on one of the movable body and the outside of the movable body, and the measurement surface is disposed on the other of the movable body and the exterior of the movable body, and receives light from the measurement surface. A position measuring system having at least one head and measuring position information of the moving body based on an output of the head;
A pattern generator for generating a pattern on the object;
A mark detection device for detecting a mark given to the object;
The moving body is driven according to the position information, and at the same time, at least one of pattern formation on the object by the pattern generation device and detection of a mark on the object by the mark detection device, the position information An exposure apparatus comprising: a control device that collects deviations from reference information corresponding to the position information.   The exposure apparatus according to claim 32, wherein the control device collects the deviation with respect to a position of an irradiation point of the measurement light on the measurement surface.   The said control apparatus collects the said shift | offset | difference more than the area | region on the said measurement surface outside this area | region about the area | region on the said measurement surface where the difference of the said shift | offset | difference with the model assumed with respect to the said shift | offset | difference is large. 34. The exposure apparatus according to 33.   The control device collects more of the deviation than the area on the measurement surface outside the area for the area on the measurement surface where the difference of the deviation difference from the model assumed for the deviation is significant. The exposure apparatus according to claim 33.   36. The exposure apparatus according to any one of claims 32 to 35, wherein the control device interrupts the collection of the deviation when at least one of acceleration and speed of the moving body exceeds an allowable range.   37. The exposure apparatus according to any one of claims 32 to 36, wherein the control device interrupts the collection of the deviation when the moving body is stopped.   38. The control device according to any one of claims 32 to 37, wherein the control device interrupts the collection of the deviation when it is clear that the moving body moves only in a partial region within the predetermined plane. The exposure apparatus described.   The exposure apparatus according to any one of claims 32 to 38, wherein the control device collects the deviation only when the moving body maintains a reference posture.   The said control apparatus collects the said shift | offset | difference, when the said moving body is located in the area | region to which the said moving body moves when the pattern generation apparatus forms the pattern with respect to the said object. The exposure apparatus according to one item.   The said control apparatus collects the said shift | offset | difference, when the said moving body is located in the area | region where the said moving body moves when the mark on the said object is detected by the said mark detection apparatus. The exposure apparatus according to one item.   The exposure apparatus according to any one of claims 32 to 41, wherein the control device creates calibration information for correcting the position information using the collected deviation.   43. The exposure apparatus according to claim 42, wherein the control device uses only the deviation within a predetermined time after the collection among the collected deviations.   44. The exposure apparatus according to claim 42 or 43, wherein the control apparatus creates the calibration information every time a pattern is formed on a predetermined number of the objects.   45. The exposure apparatus according to any one of claims 42 to 44, wherein the control device creates the calibration information only when a certain accuracy is guaranteed for the calibration information.   The exposure apparatus according to any one of claims 42 to 45, wherein the control device corrects the position information using the calibration information, and drives the movable body according to the corrected position information.   47. The exposure apparatus according to any one of claims 32 to 46, further comprising an interferometer system that measures position information of the movable body.   48. The exposure apparatus according to claim 47, wherein the control apparatus predicts the position information measured based on an output of the head from a measurement result of the interferometer system, and uses the position information as the reference information. The measurement surface has a grating whose periodic direction is at least one axial direction in the predetermined plane,
49. The exposure apparatus according to any one of claims 32 to 48, wherein the head has the periodic direction as a measurement direction. The measurement surface includes first and second gratings having first and second directions orthogonal to each other in the predetermined plane as periodic directions,
49. The exposure apparatus according to any one of claims 32 to 48, wherein the position measurement system uses a plurality of heads each including at least one head that irradiates measurement light onto one of the first and second gratings.   49. The exposure apparatus according to any one of claims 32 to 48, wherein the head has a direction perpendicular to the predetermined plane as a measurement direction.   52. The exposure apparatus according to any one of claims 32 to 51, wherein the pattern generation device forms a pattern by irradiating a sensitive layer of the object with an energy beam. The pattern generation apparatus includes an optical system,
53. The exposure apparatus according to claim 52, further comprising a liquid supply device that supplies a liquid between the optical system and the object. Forming a pattern on the object using the exposure apparatus according to any one of claims 32 to 53;
Applying a treatment to the object on which the pattern is formed.

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