WO2024219234A1

WO2024219234A1 - Substrate processing method and substrate processing apparatus

Info

Publication number: WO2024219234A1
Application number: PCT/JP2024/013834
Authority: WO
Inventors: 幸伸宮本; 貴大工
Original assignee: 東京エレクトロン株式会社
Priority date: 2023-04-17
Filing date: 2024-04-03
Publication date: 2024-10-24

Abstract

The present invention addresses the problem of providing a substrate processing method that makes it possible to perform peripheral exposure in accordance with the state of an outer edge in a lower layer film.　A substrate processing method according to one aspect of the present disclosure comprises: generating edge information indicating a relationship between a circumferential position (Xθ) around the center of a substrate having a first coating formed on a surface thereof and an outer edge position (w1-w3) of the first coating in a radial direction (Xr) of the substrate, on the basis of a captured image obtained by imaging the peripheral region on the surface of the substrate; setting an exposure map indicating a relationship between the circumferential position (Xθ) and a set value (Er) of an exposure width in the radial direction, on the basis of the edge information; forming a second coating in at least the peripheral region of the surface after the captured image is obtained; and exposing the second coating in the peripheral region in accordance with the exposure map.

Description

Substrate processing method and substrate processing apparatus

This disclosure relates to a substrate processing method and a substrate processing apparatus.

Patent Document 1 discloses a substrate inspection device. This substrate inspection device is equipped with an edge detection unit configured to detect a target edge, which is the edge of the coating to be inspected, based on inspection image data obtained from a captured image of the peripheral portion of a substrate on which multiple coatings are formed.

JP 2020-144102 A

This disclosure provides a substrate processing method and substrate processing apparatus that enable peripheral exposure that is tailored to the condition of the outer edge of the underlying film.

A substrate processing method according to one aspect of the present disclosure includes: generating edge information indicating a relationship between a circumferential position around a center of a substrate and an outer edge position of the first coating in a radial direction of the substrate based on an image obtained by imaging a peripheral region of the surface of the substrate having a first coating formed thereon; setting an exposure map indicating a relationship between the circumferential position and a set value of an exposure width in the radial direction based on the edge information; forming a second coating on at least the peripheral region of the surface after the image is obtained; and exposing the second coating in the peripheral region according to the exposure map.

The present disclosure provides a substrate processing method and substrate processing apparatus that enable peripheral exposure that is tailored to the state of the outer edge of the underlying film.

FIG. 1 is a plan view illustrating an example of a wafer processing system. FIG. 2 is a front view illustrating an example of a wafer processing system. FIG. 3 is a schematic diagram showing an example of a liquid treatment apparatus. FIG. 4 is a plan view illustrating an example of an inspection device. FIG. 5 is a front view showing a schematic diagram of an example of an inspection device. Fig. 6A is a schematic diagram showing an example of a peripheral exposure apparatus, and Fig. 6B is a schematic side view showing an example of a mask member. FIG. 7 is a block diagram illustrating an example of a functional configuration of the control device. FIG. 8 is a block diagram illustrating an example of a hardware configuration of the control device. FIG. 9 is a flow chart showing an example of a substrate processing method. 10(a), 10(b), 10(c), 10(d), 10(e), and 10(f) are schematic views illustrating the substrate processing method. Fig. 11A is a diagram showing an example of a captured peripheral image, and Fig. 11B is a graph showing an example of edge information. Fig. 12(a) is a graph visualizing an example of an exposure map, and Fig. 12(b) is a diagram showing an example of a film state after exposure and development. FIG. 13 is a graph showing an example of the relationship between edge information and an exposure map. Fig. 14A is a graph showing an example of a measurement result of an exposure width after exposure, and Fig. 14B is a graph showing an example of difference information obtained by the inspection process. 15(a), 15(b), 15(c), 15(d), 15(e), and 15(f) are schematic views illustrating the substrate processing method. 16(a), 16(b), 16(c), and 16(d) are schematic views illustrating the substrate processing method. Fig. 17A is a schematic diagram illustrating the influence of warping, and Fig. 17B is a schematic diagram showing an example of a peripheral exposure device.

Below, one embodiment will be described with reference to the drawings. In the description, identical elements or elements having the same functions are given the same reference numerals, and duplicated descriptions will be omitted. Some drawings show an orthogonal coordinate system defined by the X-axis, Y-axis, and Z-axis. In the following embodiment, the X-axis and Y-axis correspond to the horizontal direction, and the Z-axis corresponds to the up-down direction.

<Wafer Processing System>
First, the configuration of a wafer processing system according to this embodiment will be described. Figures 1 and 2 are a plan view and a front view, respectively, that show a schematic outline of the configuration of a wafer processing system 1. In this embodiment, the wafer processing system 1 (substrate processing apparatus) will be described as an example of a photolithography processing system that performs a resist film forming process and a developing process on a wafer W (substrate).

As shown in FIG. 1, the wafer processing system 1 has a cassette station 2 where cassettes C containing multiple wafers W are loaded and unloaded, and a processing station 3 equipped with multiple processing devices that perform predetermined processing on the wafers W. The wafer processing system 1 has a configuration in which the cassette station 2, the processing station 3, and an interface station 4 that transfers the wafers W between them and an exposure device (not shown) adjacent to the opposite side of the processing station 3 are integrally connected. Note that, as shown in FIG. 1, two processing stations 3 are installed between the cassette station 2 and the interface station 4, but there may be one or three or more processing stations installed.

The cassette station 2 is provided with a plurality of cassette placement tables 21, wafer transfer devices 22, and wafer transfer devices 23. In the cassette station 2, the wafer W is transferred between the cassette C placed on the cassette placement table 21 and the processing station 3 by the wafer transfer device 22 or the wafer transfer device 23. For this purpose, the wafer transfer device 22 and the wafer transfer device 23 each have a drive mechanism in the X direction, Y direction, up and down direction, and around the vertical axis (θ direction) as necessary, and may have a drive mechanism in all directions. At least one of the wafer transfer device 22 and the wafer transfer device 23 is capable of transferring the wafer W to and from the cassette C, and is also capable of transferring the wafer W to and from the processing station 3. The transfer operation of the wafer W to and from the processing station 3 means, for example, transferring the wafer W to and from the third block G3 having a transfer device accessible to the wafer transfer device 33 in the processing station 3 described later. The third block G3 may include multiple transfer devices (not shown) arranged vertically.

An inspection device U3 that performs inspections on the wafer W may be located at a position accessible to either the wafer transport device 22 or the wafer transport device 23. The inspection device U3 may be located in the cassette station 2 (e.g., the third block G3). The inspection device U3 may be located in the processing station 3 instead of or in addition to the cassette station 2, or may be located in the interface station 4.

The processing station 3 is provided with a plurality of blocks, for example, a first block G1, a second block G2, and a fourth block G4. Also, as shown in FIG. 2, a plurality of layers 31 each including a first block G1 and a second block G2 are stacked vertically. For example, the first block G1 is provided on the front side of the processing station 3 (negative side in the X direction in FIG. 1), and the second block G2 is provided on the rear side of the processing station 3 (positive side in the X direction in FIG. 1). The fourth block G4 is provided at the connection between the processing station 3 arranged on the cassette station 2 side (negative side in the Y direction in FIG. 1) and the processing station 3 arranged on the interface station 4 side (positive side in the Y direction in FIG. 1). The fourth block G4 may be provided with a plurality of transfer devices arranged vertically. Also, the above-mentioned third block G3 may be provided within the processing station 3.

In the first block G1, multiple film processing devices U1 are arranged. The film processing devices U1 are, for example, a film forming device for patterning or a developing processing device. The film forming device for patterning may include, for example, a resist film forming device as well as an anti-reflective film forming device. At least some of the multiple film processing devices U1 may be devices that perform film processing using a processing liquid. The film processing includes forming a film and performing a developing process.

In the first block G1, for example, multiple membrane processing devices U1 are arranged in a horizontal line. Note that the number, arrangement, and type of these membrane processing devices U1 can be selected arbitrarily.

In these patterning film forming devices and developing treatment devices, for example, a specific processing liquid or a specific gas is supplied onto the wafer W. In this way, in the patterning film forming device, a resist film is formed that is used as a mask when forming a pattern on the underlying film, and an anti-reflective film is formed to efficiently perform a light irradiation process, an example of which is an exposure process. Meanwhile, in the developing treatment device, a portion of the exposed resist film is removed to form the uneven shape that serves as the mask.

For example, in the second block G2, heat treatment devices U2 for performing heat treatment such as heating and cooling of the wafer W are arranged vertically and horizontally. Also, in the second block G2, a hydrophobization treatment device (not shown) for performing a hydrophobization treatment to improve the fixation of the resist liquid and the wafer W, and a peripheral exposure device U4 for exposing the outer periphery of the wafer W are arranged vertically (Z direction in FIG. 2) and horizontally. The number and arrangement of these heat treatment devices, hydrophobization treatment devices, and peripheral exposure devices U4 can be selected arbitrarily. The peripheral exposure device U4 may be arranged in the interface station 4 instead of or in addition to the processing station 3 (e.g., the second block G2). Both the inspection device U3 and the peripheral exposure device U4 may be arranged in the processing station 3 or in the interface station 4.

As shown in FIG. 1, a wafer transport area 32 is formed in the area between the first block G1 and the second block G2 in a plan view. In the wafer transport area 32, for example, a wafer transport device 33 is disposed.

The wafer transport device 33 has a transport arm that can move freely in, for example, the Y direction, the front-rear direction, the θ direction, and the up-down direction. The wafer transport device 33 moves within the wafer transport area 32 and can transport the wafer W to a predetermined device within the surrounding first block G1, second block G2, third block G3, and fourth block G4. When there are multiple processing stations 3 as in FIG. 1, the wafer transport device 33 provided in the processing station 3 located on the interface station 4 side can transport the wafer W to a predetermined device within the fifth block G5 described below in addition to the first block G1, second block G2, and fourth block G4.

For example, multiple wafer transport devices 33 are arranged vertically. One wafer transport device 33 can transport a wafer W to a specific device located at the height of the upper layers 31 out of the multiple layers 31 stacked vertically. Another wafer transport device 33 can transport a wafer W to a specific device located at the height of the multiple layers 31 located below the layers 31. Multiple wafer transport areas 32 (see the areas lined up vertically in Figure 2) are provided to enable such transportation of wafers W. Note that the number of wafer transport devices 33 and the number of layers 31 corresponding to one wafer transport device 33 can be selected arbitrarily, such as providing a wafer transport device 33 for each layer 31.

Furthermore, the wafer transport area 32 or the first block G1 or the second block G2 may have a shuttle transport device (not shown). The shuttle transport device transports the wafer W in a straight line between a space adjacent to one side of the processing station 3 and another space adjacent to the opposite side.

The interface station 4 is provided with a fifth block G5 equipped with multiple transfer devices, a wafer transport device 41, and a wafer transport device 42. The interface station 4 transports the wafer W between the exposure device and the fifth block G5, where the wafer W is transferred by the wafer transport device 33, using the wafer transport device 41 or the wafer transport device 42. For this purpose, the wafer transport device 41 and the wafer transport device 42 each include a drive mechanism for the X direction, Y direction, up and down direction, and around the vertical axis (θ direction) as necessary, and may include a drive mechanism for all directions. At least one of the wafer transport device 41 and the wafer transport device 42 can support the wafer W and transport the wafer W between the transfer device in the fifth block G5 and the exposure device.

A cleaning device for cleaning the surface of the wafer W and the aforementioned peripheral exposure device U4 may be provided in a position within the interface station 4 that is accessible to either the wafer transport device 41 or the wafer transport device 42. In one example, the cleaning device and peripheral exposure device U4 may be provided in the location indicated by the dashed square within the interface station 4 in FIG. 1.

The above wafer processing system 1 is provided with a control device 100. The control device 100 is, for example, a computer, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of wafers W in the wafer processing system 1. The program storage unit also stores a program for controlling the operation of the drive systems of the above-mentioned various processing devices and transport devices, etc., to realize wafer processing in the wafer processing system 1. The above program may be recorded on a computer-readable storage medium H, and installed in the control device 100 from the storage medium H.

Operation of the Wafer Processing System
The above is the configuration of the wafer processing system 1. Next, an example of wafer processing performed using the wafer processing system 1 configured as above will be described.

First, a cassette C containing multiple wafers W is carried into the cassette station 2 of the wafer processing system 1 and placed on the cassette placement table 21. Next, each wafer W in the cassette C is sequentially removed by the wafer transfer device 22 or the wafer transfer device 23 and transferred to the transfer device in the third block G3.

The wafer W transferred to the transfer device of the third block G3 is supported by the wafer transfer device 33 and transferred to the hydrophobization treatment device provided in the second block G2, where the hydrophobization treatment is performed. Next, the wafer W is transferred by the wafer transfer device 33 to the resist film forming device, where a resist film is formed on the wafer W, and then transferred to the heat treatment device for pre-baking, and then transferred to the transfer device of the fifth block G5. Note that, when there are multiple processing stations 3 as shown in Figures 1 and 2, the wafer W is placed once in the transfer device of the fourth block G4 before being transferred to the transfer device of the fifth block G5, and then transferred between the multiple wafer transfer devices 33. The wafer W is also transferred by the wafer transfer device 33 to the peripheral exposure device U4, where the peripheral area of the wafer W is exposed.

The wafer W transported to the transfer device of the fifth block G5 is transported by the wafer transport device 41 and the wafer transport device 42 to the exposure device connected to the interface station 4, where it is exposed to a predetermined pattern. The wafer W may be cleaned in a cleaning device before the exposure process.

The exposed wafer W is transported to the transfer device in the fifth block G5 by the wafer transport device 41 and the wafer transport device 42. It is then transported to the heat treatment device by the wafer transport device 33 and subjected to post-exposure baking.

The exposed and baked wafer W is transported by the wafer transport device 33 to the development processing device and developed. After development is complete, the wafer W is transported by the wafer transport device 33 to the heat treatment device U2 and post-baked.

Then, the wafer W is transported by the wafer transport device 33 to the delivery device in the third block G3, and then transported by the wafer transport device 22 or wafer transport device 23 in the cassette station 2 to the cassette C on a predetermined cassette mounting table 21. Thus, a series of photolithography processes is completed. Note that a resist film may be formed on at least the peripheral region of the wafer W before or after exposure in the exposure device, and the resist film may be exposed by the peripheral exposure device U4, and then developed in the development processing device.

<Liquid Treatment Device>
Next, referring to Fig. 3, a liquid treatment device that forms a coating using a treatment liquid will be described as an example of the film treatment device U1. In the present disclosure, the film of the treatment liquid formed by applying the treatment liquid and the film formed by heat-treating the film of the treatment liquid are collectively referred to as "coating". The film treatment device U1 includes, for example, a rotating holder 45 and a liquid supply unit 50.

The rotating holder 45 includes a rotating drive unit 46, a shaft 47, and a holder 48. The rotating drive unit 46 operates based on an operation signal from the control device 100 to rotate the shaft 47. The rotating drive unit 46 includes a power source such as an electric motor. The holder 48 is provided at the tip of the shaft 47. A wafer W can be placed on the holder 48. The holder 48 is configured to hold the wafer W approximately horizontally, for example, by suction. That is, the holder 48 rotates the wafer W around a central axis (rotation axis) perpendicular to the surface Wa of the wafer W while the wafer W is in an approximately horizontal position.

The liquid supply unit 50 is configured to supply the processing liquid L to the surface Wa of the wafer W. The processing liquid L is, for example, a resist liquid for forming a resist film (hereinafter, referred to as "processing liquid Lr"). The resist material contained in the processing liquid Lr may be a positive resist material or a negative resist material. A positive resist material is a resist material in which exposed areas dissolve and unexposed areas remain. A negative resist material is a resist material in which unexposed areas dissolve and exposed areas remain. In the following, an example will be described in which the processing liquid L is the processing liquid Lr and the resist material contained in the processing liquid Lr is a negative resist material.

The liquid supply unit 50 includes a liquid source 51, a pump 52, a valve 53, a nozzle 54, a pipe 55, and a drive mechanism 56. The liquid source 51 functions as a supply source of the processing liquid Lr. The pump 52 operates based on an operation signal from the control device 100, sucks the processing liquid Lr from the liquid source 51, and sends it to the nozzle 54 via the pipe 55 and the valve 53.

The nozzle 54 is positioned above the wafer W so that its discharge port faces the surface Wa of the wafer W. The nozzle 54 is configured to discharge the processing liquid Lr pumped out by the pump 52 onto the surface Wa of the wafer W. The piping 55 connects, in order from the upstream side, the liquid source 51, the pump 52, the valve 53, and the nozzle 54. The drive mechanism 56 operates based on an operation signal from the control device 100, and is configured to move the nozzle 54 horizontally and vertically.

In the film processing device U1, the wafer W on which the film of the processing liquid Lr has been formed is transferred to one of the heat processing devices U2, which performs heat processing on the wafer W. This forms a resist film on the surface Wa of the wafer W. As described above, the film processing device U1 and the heat processing device U2 may constitute a film forming section that forms a resist film, which is a type of coating.

<Inspection equipment>
Next, an example of the inspection device U3 will be described with reference to Fig. 4 and Fig. 5. The inspection device U3 (inspection unit) is a device that generates one or more types of image information for inspecting the state of the wafer W. The inspection device U3 includes, for example, a housing 68, a rotating and holding unit 60, a surface imaging unit 70, and a peripheral imaging unit 80. The rotating and holding unit 60, the surface imaging unit 70, and the peripheral imaging unit 80 are disposed in the housing 68. A transfer port 69 is formed in one side wall of the housing 68 for transferring the wafer W into the housing 68 and transferring the wafer W out of the housing 68.

The rotating and holding unit 60 is a unit that holds and rotates the wafer W and moves the wafer W within the housing 68. The rotating and holding unit 60 includes a holding table 61, driving

mechanisms

62 and 63, and a guide rail 64. The holding table 61 is, for example, a suction chuck that holds the wafer W approximately horizontally by suction or the like.

The driving mechanism 62 includes a power source such as an electric motor, and drives the holding table 61 to rotate. That is, the driving mechanism 62 rotates the wafer W held on the holding table 61. The wafer W may be placed on the holding table 61 so that the central axis of rotation by the driving mechanism 62 approximately coincides with the center of the wafer W. The driving mechanism 62 may include an encoder for detecting the rotational position (rotation angle) of the holding table 61 about the central axis. In this case, the imaging position of the wafer W by the surface imaging unit 70 and the peripheral imaging unit 80 can be associated with the rotational position of the wafer W. If the wafer W includes an index portion (e.g., a notch) that indicates a reference position in the circumferential direction, the attitude of the wafer W can be identified based on the index portion determined by the surface imaging unit 70 and the peripheral imaging unit 80 and the rotational position detected by the encoder.

The driving mechanism 63 is, for example, a linear actuator, and moves the holding table 61 along the guide rail 64. That is, the driving mechanism 63 transports the wafer W held on the holding table 61 between one end and the other end of the guide rail 64. Therefore, the wafer W held on the holding table 61 can move between a first position closer to the loading/unloading port 69 and a second position closer to the peripheral imaging unit 80. The guide rail 64 extends linearly (for example, straight) within the housing 68.

The surface imaging unit 70 includes a camera 71 and a lighting module 72. The camera 71 includes a lens and an imaging element (e.g., a CCD image sensor or a CMOS image sensor). The camera 71 faces the lighting module 72 in the horizontal direction. In other words, the camera 71 and the lighting module 72 are aligned along the horizontal direction.

The lighting module 72 includes a half mirror 73 and a light source 74. The half mirror 73 is arranged in the housing 68 at an angle of approximately 45° to the horizontal. The half mirror 73 is located above the middle part of the guide rail 64. The half mirror 73 has a rectangular shape, and extends so as to intersect with the extension direction of the guide rail 64 when viewed from above. The length of the half mirror 73 is set to be greater than the diameter of the wafer W.

The light source 74 is located above the half mirror 73. The light emitted from the light source 74 passes through the entire half mirror 73 and is irradiated downward (toward the guide rail 64). The light that passes through the half mirror 73 is reflected by an object located below the half mirror 73, then reflected again by the half mirror 73, passes through the lens of the camera 71, and enters the image sensor of the camera 71. That is, the camera 71 can capture an image of an object present in the irradiation area of the light source 74 via the half mirror 73. For example, when the holding table 61 that holds the wafer W moves along the guide rail 64 by the driving mechanism 63, the camera 71 can capture an image of the surface Wa of the wafer W that passes through the irradiation area of the light source 74. The image data captured by the camera 71 is transmitted to the control device 100.

The peripheral imaging unit 80 includes a camera 81, a lighting module 82, and a mirror member 83. The camera 81 includes a lens and an imaging element (e.g., a CCD image sensor or a CMOS image sensor). The camera 81 faces the lighting module 82 in the horizontal direction. In other words, the camera 81 and the lighting module 82 are aligned along the horizontal direction.

The lighting module 82 is disposed above the wafer W held on the holding table 61. The lighting module 82 includes a light source 84 and a half mirror 85. As shown in FIG. 5, the half mirror 85 is disposed at an angle of approximately 45° to the horizontal direction. As shown in FIG. 4 and FIG. 5, the mirror member 83 is disposed below the lighting module 82. The mirror member 83 includes a main body formed of an aluminum block and a reflective surface.

When the wafer W held on the holding table 61 is in the second position, the reflective surface of the mirror member 83 faces the end face Wb of the wafer W held on the holding table 61 and the peripheral area on the back surface of the wafer W. The reflective surface of the mirror member 83 is inclined with respect to the rotation axis of the holding table 61. The reflective surface of the mirror member 83 is mirror-finished. For example, the reflective surface may have a mirror sheet attached, may be aluminum plated, or may have aluminum material vapor-deposited thereon. This reflective surface is a curved surface recessed radially outward of the wafer W held on the holding table 61.

In the lighting module 82, the light emitted from the light source 84 passes entirely through the half mirror 85 and is irradiated downward. A portion of the light that passes through the half mirror 85 is reflected at the peripheral region of the surface Wa of the wafer W. This reflected light does not head toward the reflective surface of the mirror member 83, but is further reflected by the half mirror 85 before entering the imaging element of the camera 81.

Meanwhile, another portion of the light that passes through the half mirror 85 is reflected by the reflective surface of the mirror member 83 located below the half mirror 85. When the wafer W held on the holding table 61 is in the second position, the light reflected by the reflective surface of the mirror member 83 is mainly reflected by the edge surface Wb of the wafer W. The reflected light is reflected in turn by the reflective surface of the mirror member 83 and the half mirror 85, and enters the imaging element of the camera 81.

In this way, the light reflected from the peripheral region on the surface Wa of the wafer W and the light reflected from the end face Wb of the wafer W enter the image sensor of the camera 81 via different optical paths. That is, when the wafer W held on the holding table 61 is in the second position, the camera 81 is configured to capture both the peripheral region on the surface Wa of the wafer W and the end face Wb of the wafer W to generate an image of the peripheral region of the surface Wa and an image of the end face Wb. The captured image data captured by the camera 81 is transmitted to the control device 100. Note that the inspection device U3 may be configured in any way as long as it is capable of capturing an image of the peripheral region of the surface Wa and generating an image of the peripheral region. The peripheral region of the surface Wa can also be referred to as the peripheral region (peripheral region) of the surface Wa, and refers to a ring-shaped region including the periphery of the surface Wa and the vicinity of the periphery. The peripheral imaging unit 80 may further generate an image of the end face Wb without capturing an image of the peripheral region of the front surface Wa, and the inspection device U3 may have an imaging unit capable of generating an image of the end face Wb, separate from the peripheral imaging unit 80. The amount of warping of the wafer W may be measured from an image of the end face Wb that does not include the peripheral region of the front surface Wa.

<Peripheral exposure device>
Next, the peripheral exposure device U4 will be described with reference to Figures 6(a) and 6(b). The peripheral exposure device U4 (peripheral exposure section) is a device that exposes the peripheral region on the front surface Wa of the wafer W. The peripheral exposure device U4 does not expose a region located inside the peripheral region. The peripheral exposure device U4 has, for example, a rotating and holding unit 110 and an exposure unit 120. The rotating and holding unit 110 and the exposure unit 120 are arranged in a housing of the peripheral exposure device U4.

The rotating and holding unit 110 is a unit that holds and rotates the wafer W. The rotating and holding unit 110 includes a holding table 111 (holding portion), driving

mechanisms

112 and 113, and a guide rail 114. The holding table 111 is, for example, a suction chuck that holds the wafer W approximately horizontally by suction or the like.

The driving mechanism 112 includes a power source such as an electric motor, and drives the holding table 111 to rotate. That is, the driving mechanism 112 rotates the wafer W held on the holding table 111. The driving mechanism 112 may include an encoder for detecting the rotational position of the holding table 111. In this case, the exposure position of the wafer W by the exposure unit 120 can be associated with the rotational position of the wafer W. The holding table 111 holds the back surface of the wafer W so that the center of rotation of the wafer W by the driving mechanism 112 approximately coincides with the center of the wafer W.

The driving mechanism 113 is, for example, a linear actuator, and moves the holding table 111 along the guide rail 114. That is, the driving mechanism 113 transports the wafer W held on the holding table 111 between one end and the other end of the guide rail 114. The guide rail 114 extends linearly (for example, straight) within the housing of the peripheral exposure device U4, and one end of the guide rail 114 is located near the exposure unit 120. When the holding table 111 holding the wafer W is at one end of the guide rail 114, the exposure unit 120 may expose the wafer W.

The exposure unit 120 is a unit that irradiates the peripheral area on the surface Wa of the wafer W with light for exposure. The exposure unit 120 irradiates the peripheral area on the surface Wa with light for exposure while the wafer W held on the holding table 111 is rotating. The exposure unit 120 includes a light source 121, an optical system member 122, a mask member 123, and a drive mechanism 124. The light source 121 may be disposed vertically above the peripheral area on the surface Wa of the wafer W disposed at a position where exposure is possible. The light source 121 irradiates downward with an energy ray (e.g., ultraviolet light) containing a wavelength component capable of exposing a resist film. The light source 121 may be, for example, an ultra-high pressure UV lamp, a high pressure UV lamp, a low pressure UV lamp, or an excimer lamp.

The optical system member 122 is disposed below the light source 121. The optical system member 122 is composed of one or more lenses. The optical system member 122 converts the exposure light from the light source 121 into approximately parallel light and irradiates the mask member 123. The light source 121 and the optical system member 122 function as an irradiation unit that irradiates the exposure light. The mask member 123 is formed with an opening 123a for adjusting the exposure area (exposure range). The parallel light from the optical system member 122 passes through the opening 123a and is irradiated onto the peripheral region of the front surface Wa of the wafer W held on the holding table 111. When a developer is supplied to the resist film whose peripheral region has been irradiated with the exposure light, the region not irradiated with the exposure light is removed.

The driving mechanism 124 includes a power source such as an electric motor, and is connected to the mask member 123. The driving mechanism 124 operates based on an operation signal from the control device 100, and moves the mask member 123 along the radial direction of the wafer W (the radial direction of the wafer W while held on the holding table 111). The radial direction of the wafer W is the radial direction of a circle around the center of the wafer W. As the driving mechanism 124 moves the mask member 123 along the radial direction, the radial size of the range in which the exposure light reaches the portion of the resist film located in the peripheral region (hereinafter simply referred to as the "exposure width") changes.

The mask member 123 is driven by the drive mechanism 124 within a moving range in the above-mentioned radial direction in which the outer edge of the surface Wa is included in the area where the exposure light reaches the surface Wa. In this case, the exposure width is determined by the distance in the above-mentioned radial direction between the outer edge of the surface Wa and the point closest to the center of the range where the exposure light reaches the surface Wa. Furthermore, when the position of the mask member 123 relative to the center of the wafer W changes in the radial direction, the radial position of the point closest to the center of the range where the exposure light reaches the surface Wa changes.

The method of changing the exposure width is not limited to driving by the driving mechanism 124. The mask member 123 may have a shutter 125 as shown in FIG. 6(b). FIG. 6(b) shows a schematic cross section of the wafer W cut along the radial direction, with the optical system member 122 omitted. The shutter 125 is a member that can adjust the opening degree of the opening 123a provided in the mask member 123. The opening degree of the opening 123a means the ratio of the area that passes the exposure light from the light source 121 and the optical system member 122 to the total area of the opening 123a.

The mask member 123 may be fixed at a position where the exposure light that has passed through the opening 123a reaches the outer edge of the surface Wa and the area inside that outer edge. A drive unit is connected to the shutter 125, and the shutter 125 is movable along the radial direction. The shutter 125 is capable of covering the area of the opening 123a that is closer to the center of the wafer W. The opening degree of the opening 123a changes depending on the radial position of the shutter 125, and as a result, the exposure width changes. In other words, the radial position of the point closest to the center within the range where the exposure light reaches the surface Wa changes depending on the radial position of the shutter 125.

The method of changing the exposure width is not limited to the driving mechanism 124 and the shutter 125. The peripheral exposure device U4 may change the exposure width by moving the holding table 111 holding the wafer W along the radial direction of the wafer W (the radial direction of the wafer W held on the holding table 111) relative to the mask member 123. In this case, the mask member 123 may be fixed at a predetermined position. By moving the holding table 111 (wafer W) in the radial direction relative to the mask member 123, the ratio of the area where the exposure light that has passed through the opening 123a reaches the wafer W and the area where the exposure light does not reach the wafer W changes when observing a cross section in the radial direction. In other words, the radial position of the wafer W relative to the mask member 123 changes the radial position of the area closest to the center within the range where the exposure light reaches the surface Wa.

<Control device functions>
7 shows a block diagram illustrating an example of the functional configuration of the control device 100. The control device 100 has, as its functional configuration (hereinafter referred to as "functional modules"), for example, an image information acquisition unit 201, an edge information generation unit 202, an exposure map setting unit 203, a map storage unit 204, a film formation control unit 205, an exposure control unit 206, and a result determination unit 207. The processes executed by these functional modules correspond to the processes executed by the control device 100.

The image information acquisition unit 201 is a functional module that acquires an image obtained by imaging the peripheral region on the surface Wa of the wafer W in a state where the coating F1 (first coating) is formed on the surface Wa. Hereinafter, an image obtained by imaging the peripheral region on the surface Wa in a state where the coating F1 (first coating) is formed on the surface Wa is referred to as a "peripheral image" (see also FIG. 11(a)). The image information acquisition unit 201 acquires the peripheral image, for example, from the inspection device U3. The coating F1 is a coating formed under a resist film (hereinafter referred to as "coating F2") formed at least in the peripheral region. The coating F1 may be any one of the multiple layers of films formed under the coating F2. Another film may exist between the coating F1 and the coating F2, or the coating F2 may be formed on the coating F1 without another film existing between the coating F1 and the coating F2.

The edge information generating unit 202 generates edge information indicating the relationship between the circumferential position around the center of the wafer W and the outer edge position of the coating F1 in the radial direction of the wafer W based on the peripheral image. The circumferential position is identified, for example, by an angle from an index portion (reference position) such as the notch described above. The outer edge position of the coating F1 is identified, for example, by the shortest distance along the radial direction between the center of the wafer W and the outer edge of the coating F1. The outer edge of the coating F1 is located inside the outer edge on the surface Wa of the wafer W. Therefore, the outer edge position of the coating F1 may be identified by the shortest distance along the radial direction between the theoretical position of the outer edge of the surface Wa and the outer edge of the coating F1.

When generating edge information, the edge information generating unit 202 may calculate the outer edge position of the coating F1 for each predetermined angle in the circumferential direction. The edge information generating unit 202 calculates the outer edge position of the coating F1 for each arbitrary angle (e.g., 1°) between 0.5° and 5°. The angle unit (e.g., 1°) used to calculate the outer edge position of the coating F1 can also be considered as the resolution of the edge information. The position of the indicator portion on the wafer W may be set to 0°. The edge information generating unit 202 may calculate the outer edge position of the coating F1 from the peripheral image by any image processing method.

The outer edge position of the coating F1 varies depending on the circumferential position, i.e., the angle from the indicator portion, and various other factors. In one example, a missing portion that is recessed inward from the average outer edge position may be formed at some points on the outer edge of the coating F1. The outer edge of the coating F1 may be an edge that is continuous as the circumferential position changes. In other words, when the surface Wa is viewed from above and the outer edge of the coating F1 is observed along the circumferential direction for one revolution starting from any position on the outer edge of the coating F1, there are no discontinuous points on the outer edge of the coating F1 (the outer edge of the coating F1 is continuous).

The exposure map setting unit 203 is a functional module that sets an exposure map indicating the relationship between the circumferential position around the center of the wafer W and the set value of the exposure width in the radial direction of the wafer W based on the edge information. The exposure map setting unit 203 may set the exposure width for each predetermined angle in the circumferential direction in the exposure map. The exposure map setting unit 203 sets the exposure width for each arbitrary angle (e.g., 1°) between 0.5° and 5°. The angle unit (e.g., 1°) when setting the exposure width can also be said to be the resolution in the exposure map. The resolution in the above-mentioned edge information may be the same as the resolution in the exposure map.

When setting the exposure map based on the edge information, the exposure map setting unit 203 may set the exposure map so that the position of one end of the exposed range that is close to the center of the wafer W is shifted by a fixed amount from the outer edge position of the coating F1 indicated by the edge information for each specified angle in the circumferential direction (for example, every 1°). In this case, even if the circumferential position (angle) differs, the difference between the outer edge position of the coating F1 in the edge information and the position of one end of the exposed range that is close to the center of the wafer W will be constant. The map storage unit 204 is a functional module that stores the exposure map set by the exposure map setting unit 203.

The film formation control unit 205 is a functional module that controls the film processing device U1 and heat processing device U2 to form a coating F2 (second coating) on at least the peripheral region of the surface Wa after the peripheral image is obtained. The film formation control unit 205 may control the film processing device U1 to form the coating F2 on the entire surface Wa, or may control the film processing device U1 to form the coating F2 on the peripheral region without forming the coating F2 on the central portion including the center of the wafer W.

The exposure control unit 206 is a functional module that controls the peripheral exposure device U4 to expose the coating F2 in the peripheral region according to the exposure map stored in the map storage unit 204. The exposure control unit 206 controls the peripheral exposure device U4 to expose the coating F2 with an exposure width set for the circumferential position according to the circumferential position.

The exposure control unit 206 may change the exposure width according to the circumferential position by moving the mask member 123 with the drive mechanism 124. The exposure control unit 206 may change the exposure width according to the circumferential position by changing the opening of the opening 123a of the mask member 123 by moving the shutter 125. The exposure control unit 206 may change the exposure width according to the circumferential position by moving the holding table 111 that holds the wafer W in the radial direction.

The result determination unit 207 is a functional module that determines whether the result of exposure according to the exposure map is normal or not. The result determination unit 207 performs the determination using an image (hereinafter referred to as a "determination image") obtained by imaging the peripheral area of the surface Wa after the exposed coating F2 is developed. The determination image (second image) may be generated in the inspection device U3 and then acquired by the image information acquisition unit 201. The peripheral image and the determination image may be obtained by the same inspection device U3, or may be obtained by different inspection devices U3.

The result determination unit 207 generates cut information indicating the relationship between the circumferential position and the inner edge position of the coating F2 (annular coating F2 after development) based on the determination captured image. The inner edge position of the coating F2 may be specified by the radial distance from the theoretical position of the outer edge of the surface Wa. Since the coating F2 is formed up to the outer edge of the surface Wa, the inner edge position of the annular coating F2 represents the exposure width. The result determination unit 207 determines whether the exposure of the coating F2 is normal or not based on the result of comparing the cut information with either the edge information or the exposure map.

<Hardware configuration of the control device>
8 illustrates an example of a hardware configuration of the control device 100. The control device 100 includes, for example, a circuit 210. The circuit 210 includes one or more processors 211, a memory 212, a storage 213, and an input/output port 214. The storage 213 includes a computer-readable storage medium, such as a hard disk. The storage medium stores a program for controlling the wafer processing system 1. That is, the storage 213 (or the storage medium) functions as the program storage unit described above. The storage medium may be a removable medium, such as a non-volatile semiconductor memory, a magnetic disk, or an optical disk.

The memory 212 temporarily stores the programs loaded from the storage medium of the storage 213 and the results of calculations by the processor 211. The processor 211 configures each functional module of the control device 100 by executing the above programs in cooperation with the memory 212. The input/output port 214 inputs and outputs electrical signals between the inspection device U3, the film processing device U1, the heat processing device U2, and the peripheral exposure device U4, etc., according to instructions from the processor 211.

When the control device 100 is configured with multiple computers, each functional module may be realized by a separate computer. Alternatively, each of these functional modules may be realized by a combination of two or more computers. In these cases, the multiple computers may be connected to each other so that they can communicate with each other and work together to execute control in the wafer processing system 1. Note that the hardware configuration of the control device 100 is not necessarily limited to configuring each functional module by a program. For example, each functional module of the control device 100 may be configured by a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) that integrates this.

[Substrate Processing Method]
9 to 14, an example of a substrate processing method executed in the wafer processing system 1 will be described. In the following, an example will be described in which a coating F2, which is a resist film, is formed on the peripheral region of a wafer W in which a concave-convex pattern has already been formed on a coating F1 serving as a base film and the coating F1 has been formed on the front surface Wa. As shown in FIG. 10(a) and the like, a coating F0, which is another coating, may be formed under the coating F1.

The substrate processing method includes imaging a peripheral region of the surface Wa of a wafer W having a coating F1 formed on the surface Wa to obtain a peripheral image, and generating edge information indicating the relationship between the circumferential position around the center of the wafer W and the outer edge position of the coating F1 in the radial direction of the wafer W based on the peripheral image. The substrate processing method also includes setting an exposure map indicating the relationship between the circumferential position and a set value of the exposure width in the radial direction of the wafer W based on the edge information, forming a coating F2 on at least the peripheral region of the surface Wa after obtaining the peripheral image, and exposing the coating F2 in the peripheral region according to the exposure map.

As shown in FIG. 9, first, the control device 100 executes step S01. The control device 100 controls the wafer processing system 1 to, for example, form a coating F1 on the front surface Wa of the wafer W. Instead of forming the coating F1 in the wafer processing system 1, the control device 100 may control the wafer processing system 1 to receive a wafer W having a coating F1 formed on its front surface Wa in another processing system. The coating F1 formed on the wafer W has a portion near the periphery removed so that the outer edge of the coating F1 is located inside the outer edge of the front surface Wa. The wafer W with the coating F1 formed on its front surface Wa is then transported to the inspection device U3.

Next, the control device 100 executes step S02. In step S02, for example, the image information acquisition unit 201 causes the inspection device U3 to image the peripheral region on the front surface Wa of the wafer W having the coating F1 formed on the front surface Wa, and acquires image data indicating the peripheral image from the inspection device U3. An example of the peripheral image is shown in FIG. 11(a). Note that in the peripheral image shown in FIG. 11(a), the circumferential position is converted to the horizontal direction on the image, and the radial direction is converted to the vertical direction on the image.

Next, the control device 100 executes step S03. In step S03, for example, the edge information generating unit 202 generates edge information (edge profile) indicating the relationship between the circumferential position and the outer edge position of the coating F1 in the radial direction from the image data obtained in step S02. The edge information generating unit 202 may calculate the outer edge position of the coating F1 in the radial direction from the image data obtained in step S02 for each predetermined angle (for example, every 1°) around the center of the wafer W.

FIG. 11(b) is a graph showing an example of edge information. In FIG. 11(b), the horizontal axis of the graph, "Xθ (°)," represents the circumferential position (or angle) around the center of the wafer W. The vertical axis of the graph, "Xr (mm)," represents the radial position from the center of the wafer W. "Eo" represents the theoretical radial position of the outer edge of the surface Wa of the wafer W, and "R" represents a value obtained by subtracting a predetermined value from Eo. In one example, Eo is 150 mm, and R is any value between 140 mm and 148 mm. "E1" is information showing the calculation result of the radial position (outer edge position) of the outer edge of the coating F1.

In the edge information, for example, the outer edge position E1 is obtained by calculating the outer edge position of the coating F1 at each circumferential position while changing the circumferential position Xθ by 1°. The edge information generating unit 202 may calculate the outer edge position of the coating F1 by repeatedly calculating the difference in pixel values between adjacent pixels on the image to identify the outer edge position of the coating F1 on the image. The edge information generating unit 202 may correspond between the circumferential position and the outer edge position of the coating F1 by identifying the position of an indicator portion formed on the wafer W on the image.

Next, the control device 100 executes step S04. In step S04, for example, the exposure map setting unit 203 sets an exposure map indicating the relationship between the circumferential position Xθ around the center of the wafer W and the set value of the exposure width in the radial direction of the wafer W based on the edge information generated in step S03. The set exposure map is stored by the map storage unit 204. The exposure map setting unit 203 may set the exposure width by setting the position of one end of the range to be exposed that is close to the center of the wafer W at predetermined angles (for example, at 1°) around the center of the wafer W. By changing the position of one end of the range to be exposed that is close to the center of the wafer W, the distance between the position of the one end and the outer edge Eo of the front surface Wa changes, and the exposure width changes.

The exposure map setting unit 203 may set the position of one end of the range to be exposed close to the center of the wafer W for each specified angle so as to follow the shape of the outer edge position E1 indicated by the edge information. An example of exposure map setting is visualized in FIG. 12(a). FIG. 12(a) shows a graph representing the change in the position of one end of the range to be exposed close to the center of the wafer W with respect to the circumferential position. The distance between the position of one end of the range to be exposed close to the center of the wafer W and the outer edge Eo of the front surface Wa is the exposure width, and "Ees" is information indicating the setting value of the exposure width according to the circumferential position.

The exposure map setting unit 203 sets the exposure map (exposure width Ees) so that the tendency of the exposure width to change with circumferential position follows the tendency of the exposure width to change with circumferential position of the outer edge position of the coating F1 indicated by the edge information. The exposure map setting unit 203 sets the exposure map so that, for example, at any circumferential position Xθ, one end of the range to be exposed that is closer to the center of the wafer W is located inside the outer edge of the coating F1, and the difference between the one end and the outer edge of the coating F1 is smaller than a predetermined value. The predetermined value may be about 0.5 mm to 3 mm, or about 0.5 mm to 2 mm.

By adjusting the exposure map settings to the shape of the outer edge of the coating F1 formed under the coating F2, the exposure width setting value differs depending on the circumferential position Xθ. In the example shown in FIG. 12(a), in a certain range of the circumferential position Xθ, the exposure width is set to "w1", in another range, the exposure width is set to "w2", and in another range, the exposure width is set to "w3". Note that even between two exposure widths of w1, w2, and w3 (for example, between the change from w1 to w2), the exposure width is set in accordance with the change in the outer edge of the coating F1.

FIG. 12(b) shows a schematic diagram of the relationship between the annular coating F2 after exposure and development and the coating F1. In FIG. 12(b), the area with many diagonal lines represents the coating F1, and the area with many dots represents the coating F2. By setting the exposure width Ees along the outer edge of the coating F1, as shown in FIG. 12(b), the annular coating F2 after exposure and development is formed, for example, so as to cover the entire outer edge of the coating F1, and the inner edge shape of the coating F2 is formed along the outer edge of the coating F1.

13 shows an example of the calculation result of the outer edge position of the coating F1 (outer edge position E1) and the setting result of the exposure width in the exposure map (exposure width Ees) different from those in FIG. 11(b) and FIG. 12(a). Unlike FIG. 11(b) and FIG. 12(a), in FIG. 13, the vertical axis represents the radial distance from the outer edge Eo of the surface Wa. As shown in FIG. 13, the exposure map setting unit 203 may set the exposure width so that the position of one end of the exposed range close to the center of the wafer W is shifted by a constant value from the outer edge position of the coating F1 indicated by the edge information at every predetermined angle (for example, every 1°). In this case, the difference between the exposure width Ees and the outer edge position E1 is constant at every circumferential position Xθ. In other words, the exposure width Ees is offset by a constant value from the outer edge position E1 in the entire range from 0° to 360° around the center of the wafer W. The fixed offset value may be approximately 0.5 mm to 5.0 mm, or approximately 0.5 mm to 3.0 mm.

Table 1 below shows an example of an exposure map in which the exposure width is set every 1°. Note that the exposure map shown in Table 1 is provided as an example to facilitate understanding of the contents of this disclosure.

Returning to FIG. 9, the control device 100 then executes step S05. Before step S05, the wafer W on which the coating F1 has been formed is transported from the inspection device U3 to the film processing device U1. In step S05, for example, the film formation control unit 205 controls the film processing device U1 to apply the processing liquid Lr to the entire surface Wa of the wafer W, as shown in FIG. 10(a). After the wafer W is transported to the heat processing device U2, the film formation control unit 205 controls the heat processing device U2 to heat the coating of the processing liquid Lr, as shown in FIG. 10(b). As a result, the coating F2 before exposure and development is formed on the entire surface Wa. The wafer W is then transported from the heat processing device U2 to the peripheral exposure device U4.

Next, the control device 100 executes step S06. In step S06, for example, the exposure control unit 206 controls the peripheral exposure device U4 to expose the coating F2 in the peripheral region of the front surface Wa according to the exposure map set in step S04. As shown in FIG. 10(c), the exposure control unit 206 causes the exposure unit 120 to irradiate the outer peripheral region of the front surface Wa with exposure light while rotating the wafer W held on the holding table 111 by the rotating holding unit 110. The exposure control unit 206 controls the peripheral exposure device U4 to expose the coating F2 with the set exposure width for each angle for which the exposure width is set in the exposure map.

Using the example shown in Table 1, the exposure control unit 206 controls the peripheral exposure device U4 so that the exposure width is 1.1 mm at the location where the circumferential position Xθ is 1°, and the exposure width is 1.2 mm at the location where the circumferential position Xθ is 2°. The exposure control unit 206 may continue to irradiate the exposure light by the exposure unit 120 while continuing the rotation of the wafer W without stopping it. In this case, while the circumferential position Xθ transitions from 1° to 2°, the exposure control unit 206 moves the mask member 123 by the drive mechanism 124 so that the exposure width changes from 1.1 mm to 1.2 mm, for example. The exposure control unit 206 may change the speed at which the mask member 123 is moved depending on the change width of the exposure width between two consecutive steps in the exposure map. After the peripheral region of the coating F2 is exposed according to the exposure map, the wafer W is transported from the peripheral exposure device U4 to the heat treatment device U2.

Next, the control device 100 executes step S07. In step S07, for example, the film formation control unit 205 controls the heat treatment device U2 to perform pre-development heat treatment on the wafer W (coating F2), as shown in FIG. 10(d). After the pre-development heat treatment, the wafer W is transported from the heat treatment device U2 to the film treatment device U1, which performs the development process.

Then, the film formation control unit 205 controls the film processing device U1 to supply the developer Ld to the surface Wa and develop the coating F2, as shown in FIG. 10(e). This removes the portions of the coating F2 that are not irradiated with the exposure light. The developer Ld is then washed away, forming a ring-shaped coating F2 in the outer peripheral region of the surface Wa, as shown in FIG. 10(f). After development, the wafer W is transported from the film processing device U1 to the inspection device U3.

Next, the control device 100 executes step S08. In step S08, for example, the result determination unit 207 executes an inspection process regarding the exposure to the coating F2. In one example, the result determination unit 207 uses the inspection device U3 to capture an image of the peripheral region of the wafer W after exposure and development, and acquires image data for the inspection process (the above-mentioned determination captured image) from the inspection device U3. The result determination unit 207 generates cut information indicating the relationship between the circumferential position Xθ and the inner edge position of the coating F2 in the radial direction of the wafer W from the image data for the inspection process. The result determination unit 207 may calculate the inner edge position of the coating F2 in the radial direction of the wafer W from the image data for the inspection process at predetermined angles (for example, at 1°) around the center of the wafer W.

14(a) is a graph showing an example of cut information. In FIG. 14(a), the vertical axis represents the radial distance between the outer edge Eo of the surface Wa and the inner edge position of the coating F2, i.e., the radial width of the coating F2. "Eer" is information showing the calculation result of the radial position (inner edge position) of the inner edge of the coating F2. If the peripheral exposure according to the exposure map is normal, the inner edge position Eer approximately matches the exposure width Ees shown in FIG. 13, or is offset by a predetermined value at any circumferential position Xθ from the outer edge position E1 of the coating F1. Therefore, the result determination unit 207 can determine whether the result of the peripheral exposure is normal by comparing the exposure width Ees with the inner edge position Eer. Also, the result determination unit 207 can determine whether the result of the peripheral exposure is normal by comparing the outer edge position E1 with the inner edge position Eer.

In one example, the result determination unit 207 calculates the difference between the inner edge position Eer and the outer edge position E1 for each predetermined angle (e.g., every 1°) around the center of the wafer W. FIG. 14(b) is a graph showing the difference obtained by subtracting the outer edge position E1 from the inner edge position Eer. If a constant value offset from the outer edge position E1 is designated as "OS," then if the peripheral exposure is normal, the difference between the inner edge position Eer and the outer edge position E1 will be approximately constant regardless of the circumferential position Xθ.

On the other hand, if an abnormality occurs at a certain location due to some factor, the difference between the inner edge position Eer and the outer edge position E1 will deviate from the fixed offset value (OS), as in the portion indicated by "A" in FIG. 14(b). In this case, the result determination unit 207 can determine that exposure has not been performed normally in the portion indicated by "A". It is also possible to confirm whether the inner edge position of the coating F2 has been offset by looking at the difference between the inner edge position Eer (actual value) and the exposure width Ees (set value), rather than the difference between the inner edge position Eer (actual value) and the outer edge position E1 (actual value).

The control device 100 also executes the series of processes from steps S01 to S08 for each of the subsequent wafers W. The shape (condition) of the outer edge of the coating F1 is likely to be different for each individual wafer W, and by repeating the series of processes described above, an exposure map can be set that is tailored to each individual wafer W.

[Modification]
The series of processes shown in Fig. 9 is an example and can be modified as appropriate. In the series of processes described above, the control device 100 may execute one step and the next step in parallel, or may execute each step in an order different from that of the above example. The control device 100 may execute steps with content different from that of the above example.

In the above example, when forming the coating F2 before exposure and development, the processing liquid Lr is applied to the entire surface Wa, but the processing liquid Lr does not have to be applied to the central portion of the surface Wa. Figures 15(a) to 15(f) illustrate the state of the substrate processing method when a coating film of the processing liquid Lr is formed only in the peripheral region of the surface Wa. The steps shown in Figures 15(a), 15(b), 15(c), 15(d), 15(e), and 15(f) correspond to the steps shown in Figures 10(a), 10(b), 10(c), 10(d), 10(e), and 10(f), respectively.

As shown in FIG. 15(c), an annular coating F2 is formed in and near the peripheral region of the surface Wa. The inner edge of the coating F2 is formed to be located inside the outer edge of the coating F1. Then, peripheral exposure is performed on the coating F2 by a peripheral exposure device U4 equipped with an exposure unit 120. By exposing and developing the coating F2, the unexposed portion of the annular coating F2 (a part located on the inside) is removed. Note that in the heat treatment shown in FIG. 15(b) and FIG. 15(d), heat may be applied only to the peripheral region of the wafer W, without applying heat to the central portion of the wafer W.

As shown in FIG. 16(a), the coating F2 before exposure and development may be formed to cover not only the surface Wa of the wafer W but also the end face Wb. The peripheral exposure device U4 may have an exposure unit 130 capable of performing exposure on the end face Wb in addition to the exposure unit 120. FIG. 16(b) shows a schematic representation of the coating F2 on the end face Wb before exposure and development, and FIG. 16(c) shows a schematic representation of the coating F2 on the end face Wb after exposure and development. FIG. 16(d) shows a schematic representation of the coating F2 after exposure and development. As shown in FIGS. 16(c) and 16(d), a portion of the coating F2 may be removed by exposure and development at the bottom of the end face Wb.

As described above, the inspection device U3 can obtain an image of the end face Wb in addition to the peripheral region of the front surface Wa. Therefore, the control device 100 can detect the condition of the base at the end face Wb from the image of the end face Wb. The exposure control unit 206 can then perform exposure at the end face Wb using the exposure unit 130 in accordance with the condition of the base at the end face Wb. For example, the height of the area onto which the exposure light from the exposure unit 130 is applied can be adjusted in accordance with the circumferential position Xθ in accordance with the condition of the base at the end face Wb.

In the above example, the inner edge of the coating F2 after exposure and development is located inside the outer edge of the coating F1, and the coating F2 is formed to follow the shape of the outer edge of the coating F1. Alternatively, the inner edge of the coating F2 after exposure and development may be located outside the outer edge of the coating F1, and the coating F2 may be formed to follow the shape of the outer edge of the coating F1.

In the above example, a negative resist material is used, but a positive resist material may be used to form the coating F2. In this case, for example, the coating F2 before exposure and development is formed over the entire surface Wa, and then the peripheral exposure device U4 exposes the peripheral region of the coating F2 with an exposure width according to the position of the outer edge of the coating F1. Then, the exposed area is removed by development, so that the peripheral region of the coating F2 is removed. The outer edge of the coating F2 after exposure and development may be located outside the outer edge of the coating F1, or may be located inside the outer edge of the coating F1, as long as it follows the shape of the outer edge of the coating F1.

When a positive resist material is used, the result determination unit 207 generates cut information indicating the relationship between the circumferential position and the outer edge position of the coating F2 (the coating F2 after the peripheral portion is removed after development) based on the determination captured image. The outer edge position of the coating F2 may be specified by the radial distance from the theoretical position of the outer edge of the surface Wa. Since the coating F2 before development and exposure is exposed up to the outer edge of the surface Wa, the outer edge position of the coating F2 after the peripheral portion is removed represents the exposure width. As in the case where a negative resist material is used, the result determination unit 207 determines whether the exposure of the coating F2 is normal or not based on the result of comparing either the edge information or the exposure map with the cut information.

Instead of the inspection device U3, the image information acquisition unit 201 may acquire a peripheral image obtained by imaging the peripheral region of the surface Wa from an external device other than the wafer processing system 1.

When changing the exposure width by driving the mask member 123 or the like according to the exposure map, the exposure control unit 206 may change the exposure width while stopping the rotation of the wafer W by the drive mechanism 112 of the rotation holding unit 110. For example, when an exposure map such as that shown in Table 1 is obtained, the exposure control unit 206 may control the peripheral exposure device U4 so that exposure is performed with an exposure width (1.1 mm) associated with 1° when the circumferential position Xθ (angle) is in the range of 1° to 2°. Then, the exposure control unit 206 may stop the rotation of the wafer W before the exposure light is irradiated to the location where the circumferential position Xθ is 2°, and change the position of the mask member 123, etc. to match the exposure width (1.2 mm) associated with 2°.

The exposure map may be set as shown in Table 2 below.

The exposure map shown in Table 2 indicates that the processes from "Step 1" to "Step 359" are executed in order, and the conditions for each step are set as the processing time (seconds), exposure width (mm), start angle (°), and angle range (°). The processing time indicates the execution time of the step, and the exposure width is the radial exposure range set based on the edge information. The start angle indicates the circumferential position Xθ (angle) at which the step starts, and the angle range indicates the circumferential range over which the step continues. For example, Step 1 means that the processing continues for only 0.5 seconds with the exposure width adjusted to 1.1 mm when the circumferential position Xθ is in the range from 0° to 1°. Below, several examples of control according to the exposure map shown in Table 2 will be described.

(Example 1) The exposure control unit 206 may change the exposure width by driving the mask member 123, etc., while continuing the rotation of the wafer W so that one step and the next step are executed consecutively. If there is a change in the exposure width from the previous step, the exposure control unit 206 may start driving the mask member 123 to change the exposure width at the start of the current step. Driving the mask member 123, etc. means driving the mask member 123 to change the exposure width, driving the shutter 125 to change the exposure width, or driving the holding table 111 to change the exposure width. The exposure control unit 206 may control the drive mechanism 112 that rotates and drives the holding table 111 so that the wafer W rotates at a constant rotation speed in all steps. In all steps, the exposure unit 120 may irradiate the exposure point on the front surface Wa of the wafer W with exposure light having a constant illuminance.

(Example 2) In the exposure map, the exposure width and the rotation speed of the wafer W may be set for each predetermined angle. When exposing the coating F2, the exposure control unit 206 may change the exposure width while continuing to rotate the wafer W according to the exposure map, and irradiate the surface Wa with exposure light by the exposure unit 120. In setting the exposure map, the exposure map setting unit 203 may repeatedly evaluate the difference in exposure width between two consecutive angles while changing the angle one by one. Here, one of the two angles to be evaluated at which the exposure light is first irradiated is set as the "first angle", and the other angle consecutive to the first angle is set as the "second angle". The exposure map setting unit 203 may repeatedly calculate the difference between the exposure width at the first angle and the exposure width at the second angle consecutive to the first angle while changing the second angle by the above-mentioned predetermined angle. Then, when the condition that the difference (the difference in exposure width between the first angle and the second angle) is smaller than a predetermined level is satisfied in a range that includes a predetermined number or more of consecutive angles, the exposure map setting unit 203 may set the rotation speed in that range to a value larger than the speed reference value. The predetermined level and the predetermined number are each arbitrarily set in advance at the time of setting the exposure map.

In one example, the exposure map setting unit 203 creates an exposure map such as that shown in Table 2, and then repeatedly calculates the difference between the exposure width at the target Step (exposure width at the second angle) and the exposure width at the Step immediately preceding the target Step (exposure width at the first angle) while incrementing the target Step by one. Specifically, the exposure map setting unit 203 calculates the difference between the exposure width at Step 1 and the exposure width at Step 2, and then calculates the difference between the exposure width at Step 2 and the exposure width at Step 3. Thereafter, the exposure map setting unit 203 repeatedly calculates the difference in exposure width between two successive Steps in a similar manner.

When the condition that the difference in exposure width between two consecutive steps is equal to or less than a predetermined level is satisfied in a range including a predetermined number (e.g., 3 to 7) or more consecutive target steps, the exposure map setting unit 203 sets the rotation speed to a value greater than the speed reference value in the range including the predetermined number or more target steps. To explain using a specific example, let us assume that the above-mentioned predetermined number is 5, and in the range of steps 2 to 6, the difference in exposure width from the previous step is within a predetermined level (e.g., ±0.3 mm), and the difference in exposure width between steps 6 and 7 is greater than the predetermined level. In this case, the exposure map setting unit 203 sets the rotation speed to a value (e.g., 12 rpm) greater than the speed reference value (e.g., 10 rpm) in the range of steps 2 to 6. Note that when the predetermined number is 5, if the above condition is satisfied in six or more consecutive steps, the rotation speed is set to a value greater than the speed reference value in the six or more steps.

The exposure map setting unit 203 may set the rotation speed to the speed reference value (or less than the speed reference value) for steps (angles) outside the range in which the rotation speed is set to a value greater than the speed reference value. Depending on the exposure width setting in the exposure map, there may not be a predetermined number of consecutive steps that satisfy the above condition. In this case, the exposure map setting unit 203 may set the rotation speed to the speed reference value (or less than the speed reference value) for each of all steps.

(Example 3) As in Example 2 above, when the rotation speed is increased in a range where the variation in the exposure width is continuously small, the illuminance of the exposure light may be further set for each predetermined angle in the exposure map. When exposing the coating F2, the exposure control unit 206 may control the exposure unit 120 to irradiate the exposure light onto the surface Wa while adjusting the illuminance according to the exposure map. In this case, the exposure unit 120 may be configured to be able to adjust the illuminance of the exposure light (the dose amount in the area where the exposure light hits). The dose amount in the area where the exposure light hits the surface Wa changes depending on the illuminance of the exposure light.

When setting the exposure map, the exposure map setting unit 203 may set the illuminance of the exposure light to a value greater than the illuminance reference value in the range where the rotation speed of the wafer W is set to a value greater than the speed reference value. To explain using a specific example, in an exposure map such as that shown in Table 2, if the rotation speed is set to a value greater than the speed reference value in the range of Steps 2 to 6, the illuminance of each of Steps 2 to 6 is set to a value greater than the illuminance reference value. If there are not a predetermined number or more consecutive Steps that satisfy the above condition, the exposure map setting unit 203 may set the illuminance of the exposure light to the illuminance reference value (or less than the illuminance reference value) in each of all Steps.

(Example 4) In addition to or instead of the settings in Example 2 described above, the exposure map setting unit 203 may set the rotation speed at an angle (second angle) that satisfies the condition that the difference between the exposure width at the first angle and the exposure width at the second angle subsequent to the first angle is greater than a predetermined level to a value smaller than the speed reference value. In Example 4 as well, the exposure map setting unit 203 repeatedly calculates the difference between the exposure width at the first angle and the exposure width at the second angle subsequent to the first angle while changing the second angle by the above-mentioned predetermined angle. The predetermined level used in Example 4 may be different from the predetermined level used in Example 2, and is arbitrarily set in advance at the time of setting the exposure map.

In one example, the exposure map setting unit 203 creates an exposure map such as that shown in Table 2, and then calculates the difference between the exposure width at the target Step (exposure width at the second angle) and the exposure width at the Step immediately preceding the target Step (exposure width at the first angle), repeatedly while increasing the target Step by one. Then, the exposure map setting unit 203 sets the rotation speed to a value smaller than the speed reference value in the target Step that satisfies the condition that the difference in exposure width between two consecutive Steps is greater than a predetermined level.

To explain using a specific example, assume that in Step 5, the difference in exposure width from the previous Step, Step 4, is greater than a predetermined level (e.g., ±0.5 mm), although the numerical values are different from those shown in Table 2. In this case, the exposure map setting unit 203 sets the rotation speed in Step 5 to a value (e.g., 5 rpm) smaller than the speed reference value (e.g., 10 rpm). The exposure map setting unit 203 may set the rotation speed to the speed reference value (or equal to or greater than the speed reference value) in Steps (angles) other than the range in which the rotation speed is set to a value smaller than the speed reference value. Depending on the exposure width setting in the exposure map, there may be no Step that satisfies the above condition in Example 4. In this case, the exposure map setting unit 203 may set the rotation speed to the speed reference value (or equal to or greater than the speed reference value) in each of all Steps.

(Example 5) As in Example 4 above, when the rotation speed is reduced in areas where the exposure width varies rapidly, the exposure map may further set the illuminance of the exposure light for each predetermined angle. When exposing the coating F2, the exposure control unit 206 may control the exposure unit 120 to irradiate the exposure light onto the surface Wa while adjusting the illuminance according to the exposure map. In this case, the exposure unit 120 may be configured to be able to adjust the illuminance of the exposure light (the dose in the area where the exposure light hits).

When setting the exposure map, the exposure map setting unit 203 sets the illuminance of the exposure light to a value smaller than the illuminance reference value at one or more angles where the rotation speed of the wafer W is set to a value smaller than the speed reference value. To explain using a specific example, in an exposure map such as that shown in Table 2, if the rotation speed is set to a value smaller than the speed reference value in Step 5, the illuminance in Step 5 is set to a value smaller than the illuminance reference value. If there is no Step that satisfies the above condition in Example 4, the exposure map setting unit 203 may set the illuminance of the exposure light to the illuminance reference value (or greater than the illuminance reference value) in each of all Steps.

(Example 6) Peripheral exposure on the surface Wa of the wafer W may be performed while adjusting the position of the mask member 123 in the direction in which the exposure light is emitted, depending on the state of warpage on the surface Wa of the wafer W. FIG. 17(a) shows a schematic diagram for explaining the problem when the wafer W includes warpage. In FIG. 17(a), a wafer W with no warpage (flat) in the peripheral region to be exposed is shown as "W1", a wafer W with the peripheral region to be exposed warped so as to bend upward is shown as "W2", and a wafer W with the peripheral region to be exposed warped so as to bend downward is shown as "W3". Note that a single wafer W may have a mixture of two or more of the characteristics of no warpage, upward bending, and downward bending.

In Figure 17(a), the area marked with many dots represents the range of light irradiated from the opening of mask member 123. The range of light irradiated from the opening of mask member 123 expands as the light advances, even if the optical path is adjusted by optical system member 122. When the position of mask member 123 is fixed, the distance in the Z-axis direction between mask member 123 and the area to be exposed on front surface Wa (hereinafter referred to as "irradiation distance Id"; see Figure 17(b)) differs between wafers W1, W2, and W3. If the irradiation distances Id differ from one another, the actual exposed width will change even if the exposure width setting is the same.

As shown in FIG. 7, the control device 100 may have a warpage information acquisition unit 209 as a functional block. The warpage information acquisition unit 209 acquires information indicating the state of warpage in the peripheral region of the surface Wa of the wafer W (hereinafter simply referred to as "warpage information"). The warpage information acquisition unit 209 acquires, for example, an end face image of the end face Wb of the wafer W from the inspection device U3, and acquires warpage information from the difference with a reference wafer that has no warpage. The warpage information may be information indicating the relationship between the circumferential position Xθ around the center of the wafer W and the amount of warpage in the outer edge portion of the surface Wa of the wafer W.

When generating the warpage information, the warpage information acquisition unit 209 may calculate the amount of warpage of the outer edge portion of the surface Wa for each specified angle in the circumferential direction. The warpage information acquisition unit 209 calculates the amount of warpage of the outer edge portion of the surface Wa for each arbitrary angle (e.g., 1°) between 0.5° and 5°. The angle unit (e.g., 1°) used to calculate the amount of warpage of the outer edge portion of the surface Wa can also be considered the resolution of the warpage information. The resolution of the warpage information may be the same as the resolution of the exposure map.

The driving mechanism 124 connected to the mask member 123 may change the position of the mask member 123 in the Z-axis direction. The mask member 123 having the shutter 125 may be raised and lowered by the driving mechanism connected to the mask member 123. In the exposure map, the position of the mask member 123 in the direction in which the exposure light is emitted may be set for each predetermined angle. The exposure control unit 206 may control the exposure unit 120 (e.g., the driving mechanism 124) to irradiate the exposure light onto the surface Wa while adjusting the position of the mask member 123 in the direction in which the exposure light is emitted according to the exposure map. The direction in which the exposure light is emitted from the opening 123a of the mask member 123 may be the Z-axis direction. In other words, the opening 123a (a plane including the opening edge of the opening 123a) may be perpendicular to the Z-axis direction.

When setting the exposure map, the exposure map setting unit 203 may set the position of the mask member 123 in the direction in which the exposure light is emitted for each predetermined angle based on the warp information. The exposure map setting unit 203 may set the position of the mask member 123 in the Z-axis direction so that the difference in the irradiation distance Id for each angle is reduced (e.g., so that the irradiation distance Id is constant) according to the amount of warp indicated by the warp information. The position of the mask member 123 in the Z-axis direction may be specified by the difference from a reference position (i.e., the offset value).

As shown in FIG. 17(b), the peripheral exposure device U4 may have a position sensor 132 and a position sensor 134. The position sensor 132 is a sensor that acquires information indicating the position of the mask member 123 in the Z-axis direction. The position sensor 132 acquires, for example, information indicating the position of the lower surface of the mask member 123 in the Z-axis direction. The position sensor 134 is a sensor that acquires information indicating the position of the peripheral portion (exposure target area) of the front surface Wa of the wafer W in the Z-axis direction. The irradiation distance Id can be calculated based on the position information acquired by the

position sensors

132 and 134. The

position sensors

132 and 134 may be of any type as long as they can detect information indicating the position, but are, for example, non-contact position sensors.

The control device 100 may acquire information from the

position sensors

132 and 134 while controlling the peripheral exposure device U4 to expose the coating F2 in the peripheral region of the surface Wa in accordance with the exposure map. The control device 100 may then evaluate whether the irradiation distance Id while exposure is being performed on the coating F2 in the peripheral region is within an appropriate range based on the information from the

position sensors

132 and 134. The control device 100 may sound an alarm if it evaluates that the irradiation distance Id during exposure is not within an appropriate range.

When comparing the magnitude relationship of two numerical values within a computer, either of the two criteria "greater than or equal to" and "greater than" may be used, or either of the two criteria "less than or equal to" and "less than". The choice of such criteria does not change the technical significance of the process of comparing the magnitude relationship of two numerical values. In one example of the various examples described above, at least some of the matters described in the other examples may be combined.

[Summary of the Disclosure]
[1] A substrate processing method including: generating edge information indicating a relationship between a circumferential position Xθ about a center of the wafer W and an outer edge position of the coating F1 in a radial direction of the wafer W, based on a peripheral image obtained by imaging a peripheral region of a surface Wa of a wafer W having a coating F1 formed on the surface Wa; setting an exposure map indicating a relationship between the circumferential position Xθ and a set value of an exposure width in the radial direction, based on the edge information; forming a coating F2 on at least the peripheral region of the surface Wa after the peripheral image is obtained; and exposing the coating F2 in the peripheral region in accordance with the exposure map.
In this substrate processing method, an exposure map is set based on edge information. Therefore, in the exposure map, an exposure width is set according to the radial position of the outer edge of the coating F1 under the coating F2, and exposure can be performed in the peripheral region according to the exposure map. Therefore, exposure can be performed according to the state of the outer edge of the underlying film.

Using the example shown in FIG. 12(b), consider the case where a negative resist material is used and the exposure width is set to a constant value. For example, if the position of "Er1" shown in FIG. 12(b) is set to the location closest to the center of the range to be exposed, in a certain range in the circumferential direction, the outer edge of the coating F1 may not be covered by the coating F2, and the coating F0 below the coating F1 may be exposed. In this case, a part of the exposed coating F0 may affect the part of the coating F1 that is not covered by the coating F2 and has an uneven pattern. Therefore, for example, the position of "Er2" shown in FIG. 12(b) is set to the location closest to the center of the range to be exposed when the exposure width is set to a constant value. Note that, for each individual wafer W, it is usually set to a constant exposure width without detecting the position of the outer edge of the coating F1. In this case, assuming the worst case scenario, the exposure width is set further inward with respect to the outer edge of the coating F1. In this way, when the exposure width is set at the position of "Er2", the area between the outer edge of the coating F1 and the inner edge of the coating F2 after exposure and development becomes large. As a result, the area in the coating F1 where the uneven pattern is formed in an exposed state becomes small due to the annular coating F2 formed in the peripheral area. In the above substrate processing method, the exposure width can be set according to the shape of the outer edge of the coating F1, so that it is possible to avoid a reduction in the area in the coating F1 where the uneven pattern can be formed due to the coating F2 without exposing the coating F0. Similarly, even when a positive resist material is used, it is not necessary to remove the peripheral portion of the resist film (coating F2) formed using the resist material more than necessary. Therefore, it is possible to avoid a reduction in the area in the coating F2 where the uneven pattern can be formed due to the removal of the peripheral portion.

[2] The substrate processing method according to [1] above, further comprising imaging a peripheral region of the front surface Wa of the wafer W to obtain a peripheral image.
Even in this case, it is possible to perform exposure in accordance with the state of the outer edge of the underlying film.

[3] A substrate processing method as described in [1] or [2] above, in which the exposure width is set so that, for each predetermined angle, the position of one end of the exposed range that is closest to the center of the wafer W is shifted by a constant value from the outer edge position (the outer edge position of the coating F1) indicated by the edge information.
In this case, the exposure width can be set to a shape that is closer to the shape of the outer edge of the coating F1, and a constant value can be added or subtracted from the outer edge position of the coating F1, thereby reducing the computational load when setting the exposure map.

[4] A substrate processing method according to any one of [1] to [3] above, wherein an exposure width is set for each predetermined angle in the exposure map, and the edge information provides the outer edge position for each of the predetermined angles.
In this case, the outer edge position of the coating F1 is calculated in the minimum angle unit required for setting the exposure map, so that the computational load when calculating the position of the outer edge of the coating F1 from the captured peripheral image can be reduced.

[5] The substrate processing method according to any one of [1] to [4] above, further comprising: performing development so that the coating F2 remains in the peripheral region after exposure according to the exposure map; capturing an image of the peripheral region on the front surface Wa of the wafer W after the development of the coating F2 to obtain a judgment captured image; generating cut information indicating a relationship between the circumferential position Xθ and an inner edge position of the coating F2 in the radial direction based on the judgment captured image; and determining whether or not the exposure of the coating F2 is normal based on a result of comparing the cut information with either the edge information or the exposure map.
In this case, since the actual result after exposure is inspected, the reliability of the wafer W that has been subjected to peripheral exposure can be improved.

[6] The substrate processing method according to the above [5], wherein the coating F2 is a resist film formed using a negative resist material.
In this case, it is possible to evaluate whether the result of peripheral exposure of a resist film formed using a negative resist material is appropriate.

[7] The substrate processing method according to any one of [1] to [4] above, further comprising: performing development so that a portion of the coating F2 located in the peripheral region is removed after exposure according to the exposure map; capturing an image of the peripheral region on the front surface Wa of the wafer W after the development of the coating F2 to obtain a judgment captured image; generating cut information indicating a relationship between the circumferential position Xθ and the outer edge position of the coating F2 in the radial direction based on the judgment captured image; and determining whether or not the exposure of the coating F2 is normal based on a result of comparing the cut information with either the edge information or the exposure map.
In this case, since the actual result after exposure is inspected, the reliability of the wafer W that has been subjected to peripheral exposure can be improved.

[8] The substrate processing method according to the above [7], wherein the coating F2 is a resist film formed using a positive resist material.
In this case, it is possible to evaluate whether the result of peripheral exposure of a resist film formed using a positive resist material is appropriate.

[9] The substrate processing method according to any one of [1] to [8] above, wherein exposing the coating F2 includes irradiating the surface Wa with exposure light through a mask member 123 having an opening 123a, and moving the mask member 123 radially so as to change the exposure width according to an exposure map.
In this case, since it is not necessary to drive or adjust the members and optical system for irradiating the exposure light depending on the circumferential position during exposure, the exposure width can be easily changed.

[10] The substrate processing method according to any one of [1] to [8] above, wherein exposing the coating F2 includes irradiating the surface Wa with exposure light through a mask member 123 provided with an opening 123a and a shutter 125 capable of adjusting the opening of the opening 123a, and adjusting the opening by the shutter so as to change the exposure width in accordance with an exposure map.
In this case, since it is not necessary to drive or adjust the members and optical system for irradiating the exposure light depending on the circumferential position during exposure, the exposure width can be easily changed.

[11] The substrate processing method according to any one of [1] to [8] above, wherein exposing the coating F2 includes irradiating the surface Wa of the wafer W held on the holding table 111 with exposure light from an irradiation section (light source 121 and optical system member 122) capable of irradiating exposure light, and moving the holding table 111 so as to change the exposure width according to an exposure map.
In this case, since it is not necessary to drive or adjust the members and optical system for irradiating the exposure light depending on the circumferential position during exposure, the exposure width can be easily changed.

[12] The substrate processing method according to any one of [1] to [11] above, wherein the exposure map sets an exposure width and a rotation speed of the wafer W for each predetermined angle, exposing the coating F2 includes irradiating the front surface Wa with exposure light while changing the exposure width while continuing to rotate the wafer W in accordance with the exposure map, and setting the exposure map includes calculating a difference between the exposure width at a first angle and the exposure width at a second angle consecutive to the first angle while changing the second angle by the predetermined angle in increments, and setting the rotation speed in the range to a value greater than the speed reference value when a condition that the difference is smaller than a predetermined level is satisfied in a range including a predetermined number or more consecutive angles.
It is conceivable to perform peripheral exposure while continuing to rotate the wafer W and changing the exposure width according to the circumferential position Xθ (angle). In such peripheral exposure, if the degree of change in the exposure width is continuously small, even if the rotation speed of the wafer W increases, it is easy to make the device or member for changing the exposure width follow the change in the set value of the exposure width. In the above method, when the condition that the difference between consecutive angles is smaller than a predetermined level is continuously satisfied a predetermined number of times, the rotation speed is set to a value larger than the reference value in that range. This makes it possible to shorten the processing time when performing peripheral exposure while changing the exposure width. Therefore, it is useful for achieving both exposure according to the state of the outer edge of the underlayer film and maintaining the throughput.

[13] The substrate processing method described in [12] above, wherein the exposure map further sets the illuminance of the exposure light for each predetermined angle, and exposing the coating F2 includes irradiating the exposure light onto the surface Wa while adjusting the illuminance according to the exposure map, and setting the exposure map further includes setting the illuminance of the exposure light to a value greater than the illuminance reference value in a range in which the rotation speed is set to a value greater than the speed reference value.
In this case, the difference in the amount of exposure (e.g., dose) of the exposure light between the range in which the rotation speed is faster than other ranges and the other ranges can be reduced, so that the exposure state within the front surface Wa of one wafer W can be made uniform even when the rotation speed is increased to shorten the processing time.

[14] The substrate processing method according to any one of [1] to [13] above, wherein the exposure map sets an exposure width and a rotation speed of the wafer W for each predetermined angle, exposing the coating F2 includes irradiating the front surface Wa with exposure light while changing the exposure width while continuing to rotate the wafer W in accordance with the exposure map, and setting the exposure map includes calculating a difference between the exposure width at a first angle and the exposure width at a second angle consecutive to the first angle while changing the second angle by the predetermined angle, and setting the rotation speed at an angle that satisfies a condition that the difference is greater than a predetermined level to a value greater than a speed reference value.
It is conceivable to perform peripheral exposure while continuing to rotate the wafer W and changing the exposure width according to the circumferential position Xθ (angle). In such peripheral exposure, if the degree of change in the exposure width is large, it is difficult to make a device or member for changing the exposure width follow the change in the set value of the exposure width. In the above method, the rotation speed is set to a value smaller than the speed reference value at angles where the change in the exposure width is large. This makes it easy to make a device or member for changing the exposure width follow the change in the exposure width even if there is a location where the change in the exposure width is large. Therefore, the device or member can be simplified.

[15] The substrate processing method described in [14] above, wherein the exposure map further sets the illuminance of the exposure light for each of the specified angles, and exposing the coating F2 includes irradiating the exposure light onto the surface Wa while adjusting the illuminance according to the exposure map, and setting the exposure map includes setting the illuminance of the exposure light at angles at which the rotation speed is set to a value smaller than the speed reference value to a value smaller than the illuminance reference value.
In this case, it is possible to reduce the difference in the amount of exposure (e.g., dose) of the exposure light between the angle (range) where the rotation speed is slower than other ranges and the other ranges, thereby making it possible to uniformize the exposure state within the front surface Wa of one wafer W.

[16] The substrate processing method according to any one of [1] to [15] above, wherein exposing the coating F2 includes irradiating the surface Wa with exposure light through a mask member 123 having an opening, and the exposure map sets an exposure width and a position of the mask member 123 in the direction in which the exposure light is emitted for each predetermined angle, exposing the coating F2 further includes adjusting the position of the mask member 123 in the direction in which the exposure light is emitted in accordance with the exposure map, and setting the exposure map includes setting the position of the mask member 123 in the direction in which the exposure light is emitted for each of the predetermined angles based on warpage information indicating a state of warpage in the peripheral region of the surface Wa.
If there is a warped portion in the peripheral region of the wafer W, even if the exposure width setting value is the same, a difference may occur in the region actually irradiated with the exposure light. In the above method, the position of the mask member 123 is also changed based on the warp information, so that even if the peripheral region of the wafer W includes a warped portion, it is possible to suppress a difference in the region actually irradiated with the exposure light due to the warp. Therefore, exposure can be performed more accurately in accordance with the state of the outer edge of the underlying film.

[17] A substrate processing apparatus (wafer processing system 1) including: a film forming unit (film processing apparatus U1 and heat processing apparatus U2) that forms a coating on a front surface Wa of a wafer W; a peripheral exposure device U4 that exposes a peripheral region on the front surface Wa; an image information acquisition unit 201 that acquires a peripheral image obtained by imaging the peripheral region on the front surface Wa of the wafer W in a state in which a coating F1 is formed on the front surface Wa; an edge information generation unit 202 that generates edge information indicating a relationship between a circumferential position Xθ around the center of the wafer W and an outer edge position of the coating F1 in a radial direction of the wafer W based on the peripheral image; an exposure map setting unit 203 that sets an exposure map indicating a relationship between the circumferential position Xθ and a set value of an exposure width in the radial direction based on the edge information; a film formation control unit 205 that controls the film forming unit to form a coating F2 on at least the peripheral region of the front surface Wa after the peripheral image is obtained; and an exposure control unit 206 that controls the peripheral exposure device U4 to expose the coating F2 in the peripheral region according to the exposure map.
In this substrate processing apparatus, like the substrate processing method described in [1] above, it is possible to perform exposure in accordance with the state of the outer edge of the underlying film.

[18] The substrate processing apparatus according to [17] above, further comprising an inspection device U3 capable of imaging a peripheral region on the front surface Wa of the wafer W, and the image information acquisition unit 201 acquires a peripheral image from the inspection device U3.
Even in this case, it is possible to perform exposure in accordance with the state of the outer edge of the underlying film.

[19] A substrate processing apparatus as described in [17] or [18] above, in which, when setting an exposure map based on edge information, the exposure map setting unit 203 sets an exposure width so that, for each specified angle, the position of one end of the exposed range that is closest to the center of the wafer W is shifted by a fixed value from the outer edge position (the outer edge position of the coating F1) indicated by the edge information.
In this substrate processing apparatus, similar to the substrate processing method described in [3] above, the exposure width can be set to a shape that is closer to the shape of the outer edge of the coating F1, and since it is only necessary to add or subtract a constant value to the outer edge position, the computational load when setting the exposure map can be reduced.

[20] The substrate processing apparatus described in any one of [17] to [19] above, wherein the exposure map setting unit 203 sets an exposure width for each predetermined angle in the exposure map, and the edge information generating unit 202 calculates the outer edge position for each of the predetermined angles.
In this substrate processing apparatus, similar to the substrate processing method described in [4] above, the outer edge position of the coating F1 is calculated in the minimum angle unit required for setting the exposure map, thereby reducing the computational load when calculating the position of the outer edge of the coating F1 from the peripheral image.

1...wafer processing system, W...wafer, Wa...surface, U1...film processing device, U2...heat processing device, U3...inspection device, U4...periphery exposure device, 110...rotating holding unit, 111...holding table, 120...exposure unit, 123...mask member, 123a...opening, 125...shutter, 100...control device, 201...image information acquisition unit, 202...edge information generation unit, 203...exposure map setting unit, 205...film formation control unit, 206...exposure control unit.

Claims

generating edge information indicating a relationship between a circumferential position around a center of the substrate and an outer edge position of the first coating in a radial direction of the substrate, based on an image obtained by imaging a peripheral region of the surface of the substrate having a first coating formed thereon;
setting an exposure map indicating a relationship between the circumferential position and a set value of an exposure width in the radial direction based on the edge information;
forming a second coating on at least the peripheral region of the surface after the captured image is obtained;
exposing the second coating in the peripheral region according to the exposure map.
The substrate processing method of claim 1, further comprising imaging the peripheral region of the surface of the substrate to obtain the captured image.
The substrate processing method of claim 1, wherein the exposure width is set in the exposure map so that, for each predetermined angle, the position of one end of the exposed range closest to the center of the substrate is shifted by a fixed value from the outer edge position indicated by the edge information.
In the exposure map, the exposure width is set for each predetermined angle,
4. The substrate processing method according to claim 1, wherein the edge information includes an outer edge position obtained for each of the predetermined angles.
After the exposure according to the exposure map is performed, developing is performed so that the second coating remains in the peripheral region.
imaging the peripheral region of the surface of the substrate after development of the second coating to obtain a second captured image;
generating cut information indicating a relationship between the circumferential position and an inner edge position of the second coating in the radial direction based on the second captured image;
The substrate processing method according to any one of claims 1 to 3, further comprising: determining whether or not exposure to the second coating is normal based on a result of comparing either the edge information or the exposure map with the cut information.
The substrate processing method according to claim 5, wherein the second coating is a resist film formed using a negative resist material.
performing development so as to remove a portion of the second coating located in the peripheral region after the exposure according to the exposure map is performed;
imaging the peripheral region of the surface of the substrate after development of the second coating to obtain a second captured image;
generating cut information indicating a relationship between the circumferential position and an outer edge position of the second coating in the radial direction based on the second captured image;
The substrate processing method according to any one of claims 1 to 3, further comprising: determining whether or not exposure to the second coating is normal based on a result of comparing either the edge information or the exposure map with the cut information.
The substrate processing method according to claim 7, wherein the second coating is a resist film formed using a positive resist material.
The exposing of the second coating includes:
irradiating the surface with exposure light through a mask member having an opening;
4. The substrate processing method according to claim 1, further comprising: moving the mask member in the radial direction so as to change the exposure width in accordance with the exposure map.
The exposing of the second coating includes:
irradiating the surface with exposure light through a mask member having an opening and a shutter capable of adjusting the opening size of the opening;
4. The substrate processing method according to claim 1, further comprising: adjusting the opening degree of the shutter so as to change the exposure width in accordance with the exposure map.
The exposing of the second coating includes:
irradiating the surface of the substrate held by a holder with exposure light from an irradiation unit capable of irradiating the exposure light;
4. The substrate processing method according to claim 1, further comprising: moving the holding part so as to change the exposure width in accordance with the exposure map.
In the exposure map, the exposure width and the rotation speed of the substrate are set for each predetermined angle,
exposing the second coating includes irradiating the surface with exposure light while changing the exposure width in a state where the substrate continues to rotate in accordance with the exposure map;
Establishing the exposure map includes:
Repeating the calculation of a difference between the exposure width at a first angle and the exposure width at a second angle successive to the first angle while changing the second angle by the predetermined angle;
and when the condition that the difference is smaller than a predetermined level is satisfied in a range including a predetermined number or more of consecutive angles, setting the rotation speed in the range to a value larger than a speed reference value.
In the exposure map, an illuminance of the light for exposure is further set for each of the predetermined angles,
exposing the second coating includes irradiating the surface with the exposing light while adjusting irradiance according to the exposure map;
13. The substrate processing method of claim 12, wherein setting the exposure map further comprises setting an illuminance of the exposure light to a value greater than an illuminance reference value in a range in which the rotation speed is set to a value greater than the speed reference value.
In the exposure map, the exposure width and the rotation speed of the substrate are set for each predetermined angle,
exposing the second coating includes irradiating the surface with exposure light while changing the exposure width in a state where the substrate continues to rotate in accordance with the exposure map;
Establishing the exposure map includes:
Repeating the calculation of a difference between the exposure width at a first angle and the exposure width at a second angle successive to the first angle while changing the second angle by the predetermined angle;
4. The substrate processing method according to claim 1, further comprising: setting the rotation speed at an angle that satisfies a condition in which the difference is greater than a predetermined level to a value smaller than a speed reference value.
In the exposure map, an illuminance of the light for exposure is further set for each of the predetermined angles,
exposing the second coating includes irradiating the surface with the exposing light while adjusting irradiance according to the exposure map;
15. The substrate processing method of claim 14, wherein setting the exposure map includes setting an illuminance of the exposure light at an angle at which the rotation speed is set to a value smaller than the speed reference value to a value smaller than an illuminance reference value.
exposing the second coating to light includes irradiating the surface with light for exposure through a mask member having an opening;
In the exposure map, the exposure width and the position of the mask member in the direction in which the exposure light is emitted are set for each predetermined angle,
exposing the second coating further includes adjusting a position of the mask member in a direction in which the exposing light is emitted according to the exposure map;
4. The substrate processing method according to claim 1, wherein setting the exposure map includes setting a position of the mask member in a direction in which the exposure light is emitted for each of the predetermined angles based on warpage information indicating a state of warpage in the peripheral region of the surface.
a film forming unit that forms a film on the surface of the substrate;
a peripheral exposure unit that exposes a peripheral region of the surface;
an image information acquisition unit that acquires an image of the peripheral region of the surface of the substrate in a state where a first coating is formed on the surface;
an edge information generating unit that generates edge information indicating a relationship between a circumferential direction position around a center of the substrate and an outer edge position of the first coating in a radial direction of the substrate based on the captured image;
an exposure map setting unit that sets an exposure map indicating a relationship between the circumferential position and a set value of an exposure width in the radial direction based on the edge information;
a film formation control unit that controls the film forming unit to form a second film on at least the peripheral region of the surface after the captured image is obtained;
an exposure control unit that controls the peripheral exposure unit to expose the second coating in the peripheral region in accordance with the exposure map.
an inspection unit capable of imaging the peripheral region on the front surface of the substrate;
The substrate processing apparatus according to claim 17 , wherein the image information acquisition unit acquires the captured image from the inspection unit.
The substrate processing apparatus of claim 17, wherein the exposure map setting unit, when setting the exposure map based on the edge information, sets the exposure width so that, for each predetermined angle, the position of one end of the exposed range closest to the center of the substrate is shifted by a fixed value from the outer edge position indicated by the edge information.
the exposure map setting unit sets the exposure width for each predetermined angle in the exposure map;
The substrate processing apparatus according to any one of claims 17 to 19, wherein the edge information generating section calculates the outer edge position for each of the predetermined angles.