WO2012036198A1

WO2012036198A1 - Pattern formation method and device manufacturing method

Info

Publication number: WO2012036198A1
Application number: PCT/JP2011/070975
Authority: WO
Inventors: 宗泰横田
Original assignee: 株式会社ニコン
Priority date: 2010-09-14
Filing date: 2011-09-14
Publication date: 2012-03-22
Also published as: JP2012064666A

Abstract

A pattern formation method in which a photosensitive substrate is illuminated by exposure light from projection optics via a master pattern that has lines and spaces, thereby forming a pattern on said substrate. Said method includes: determining whether or not the cumulative exposure amount needed in a projection region of the projection optics in order to form the aforementioned pattern on the aforementioned substrate falls within a prescribed range; changing the master pattern to a different master pattern that has the same pitch between lines and spaces but a different ratio of line width to space width if the aforementioned cumulative exposure amount does not fall within the prescribed range; using said different master pattern to determine exposure conditions and development conditions; exposing the substrate by means of exposure light shone on the aforementioned projection region under the determined exposure conditions; and developing the substrate under the determined development conditions.

Description

Pattern forming method and device manufacturing method

The present invention relates to a pattern forming method and a device manufacturing method.

In the manufacturing process of an electronic device such as a flat panel display, for example, as disclosed in the following patent document, a photosensitive substrate is irradiated with exposure light with exposure light from a projection optical system, and a pattern image is formed on the substrate. Is used.

JP 2003-151880 A

In the exposure apparatus, when the exposure of the substrate is performed in a state where the surface (exposure surface) of the substrate is not arranged at a predetermined position with respect to the image plane of the projection optical system, for example, the dimension of the pattern formed on the substrate is the target. There is a possibility that the pattern formed on the substrate becomes non-uniform, such as deviation from the value. As a result, a defective device may occur.

An aspect of the present invention has been made in view of the above-described problems, and the object thereof is a pattern forming method capable of suppressing nonuniformity of a pattern formed on a substrate while maintaining an exposure amount within a predetermined range, and this An object of the present invention is to provide a device manufacturing method for manufacturing a device using a pattern forming method.

The pattern forming method according to the first aspect of the present invention forms a pattern on a photosensitive substrate by irradiating the photosensitive substrate with exposure light from a projection optical system through a mask pattern having a line portion and a space portion. A pattern forming method for determining whether or not an integrated exposure amount in a projection region of a projection optical system necessary for forming the pattern on the substrate is within a predetermined range; and If not within the predetermined range, the mask pattern is changed to another mask pattern in which the pitch of the line portion and the space portion is the same, and the ratio of the line width of the line portion to the line width of the space portion is different. Determining exposure conditions and development conditions using the different mask pattern, and exposing the substrate with exposure light applied to the projection area under the exposure conditions Includes, and developing the substrate in the developing condition.

The device manufacturing method according to the second aspect of the present invention includes forming a pattern on the substrate using the pattern forming method according to the first aspect of the present invention, processing the substrate on which the pattern is formed, including.

According to an aspect of the present invention, a pattern forming method capable of suppressing nonuniformity of a pattern formed on a substrate while keeping an exposure amount within a predetermined range, and a device manufacturing method for manufacturing a device using the pattern forming method Can be provided.

FIG. 1 is a perspective view showing an example of an exposure apparatus according to the first embodiment. FIG. 2 is a diagram illustrating a relationship between the projection region and the substrate according to the first embodiment. FIG. 3 is a schematic diagram illustrating an example of a positional relationship between the first projection area and the second projection area according to the first embodiment. FIG. 4 is a schematic diagram illustrating an example of a positional relationship between the first projection area and the second projection area according to the first embodiment. FIG. 5 is a schematic diagram illustrating an example of the relationship between the mask pattern and the integrated exposure amount according to the first embodiment. FIG. 6 is a schematic diagram illustrating an example of the relationship between the mask pattern and the integrated exposure amount according to the first embodiment. FIG. 7 is a schematic diagram illustrating an example of the relationship between the mask pattern and the integrated exposure amount according to the first embodiment. FIG. 8 is a schematic diagram illustrating an example of the relationship between the mask pattern and the integrated exposure amount according to the first embodiment. FIG. 9 is a schematic diagram illustrating an example of the relationship between the mask pattern and the integrated exposure amount according to the first embodiment. FIG. 10 is a schematic diagram showing an example of a pattern of the photosensitive film according to the first embodiment. FIG. 11 is a schematic diagram illustrating an example of the relationship between the mask pattern and the integrated exposure amount according to the first embodiment. FIG. 12 is a schematic diagram for explaining a state in which the dimension of the photosensitive film changes due to the development according to the first embodiment. FIG. 13 is a flowchart illustrating an example of a pattern forming method according to the first embodiment. FIG. 14 is a flowchart illustrating an example of a pattern forming method according to the first embodiment. FIG. 15 is a flowchart illustrating an example of a pattern forming method according to the first embodiment. FIG. 16 is a schematic diagram for explaining an example of a procedure for determining a predetermined exposure condition and a predetermined development condition according to the first embodiment. FIG. 17 is a schematic diagram for explaining an example of a procedure for determining a predetermined exposure condition and a predetermined development condition according to the first embodiment. FIG. 18 is a schematic diagram for explaining an example of a procedure for determining a predetermined exposure condition and a predetermined development condition according to the first embodiment. FIG. 19 is a schematic diagram illustrating an example of a relationship between a mask pattern and an integrated exposure amount according to the second embodiment. FIG. 20 is a schematic diagram illustrating an example of the relationship between the mask pattern and the accumulated path light amount according to the second embodiment. FIG. 21 is a flowchart illustrating an example of a pattern forming method according to the second embodiment. FIG. 22 is a schematic diagram for explaining an example of a procedure for determining a predetermined exposure condition and a predetermined development condition according to the second embodiment. FIG. 23 is a schematic diagram for explaining an example of a procedure for determining a predetermined exposure condition and a predetermined development condition according to the second embodiment. FIG. 24A is a diagram illustrating a change in the integrated exposure amount accompanying a change in the defocus amount when the line widths of the line pattern and the space pattern are 4.0 [μm] and 2.0 [μm], respectively. . FIG. 24-2 is a diagram showing a change in the integrated exposure amount accompanying a change in the defocus amount when the line widths of the line pattern and the space pattern are 3.7 [μm] and 2.3 [μm], respectively. . FIG. 24C is a diagram illustrating a change in the integrated exposure amount accompanying a change in the defocus amount when the line widths of the line pattern and the space pattern are 3.5 [μm] and 2.5 [μm], respectively. . FIG. 24-4 is a diagram illustrating a change in the integrated exposure amount accompanying a change in the defocus amount when the line widths of the line pattern and the space pattern are both set to 3.0 [μm]. FIG. 25 is a diagram in which changes in the accumulated exposure amount shown in FIGS. 24-1, 24-3, and 24-4 are displayed in an overlapping manner. FIG. 26 is a diagram showing a change in the integrated exposure amount shown in FIG. 24-1 accompanying a change in light intensity. FIG. 27 is a diagram showing a change in the integrated exposure amount shown in FIGS. 24-1, 24-3, and 24-4 accompanying a change in light intensity. FIG. 28 is a flowchart illustrating an example of a pattern forming method according to the third embodiment. FIG. 29 is a flowchart illustrating an example of a device manufacturing method according to the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ orthogonal coordinate system. A predetermined direction in the horizontal plane is defined as an X-axis direction, a direction orthogonal to the X-axis direction in the horizontal plane is defined as a Y-axis direction, and a direction orthogonal to each of the X-axis direction and the Y-axis direction (that is, a vertical direction) is defined as a Z-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively.

[First Embodiment]
A first embodiment will be described. FIG. 1 is a perspective view schematically showing an example of an exposure apparatus EX according to the first embodiment. In FIG. 1, the exposure apparatus EX includes a mask stage 1 that is movable while holding a mask M, a substrate stage 2 that is movable while holding a substrate P, and interference that measures the positions of the mask stage 1 and the substrate stage 2. The operation of the measuring system 3, the illumination system IS for illuminating the mask M with the exposure light EL, the projection system PS for projecting the pattern image of the mask M illuminated with the exposure light EL onto the substrate P, and the operation of the exposure apparatus EX as a whole. And a control device 4 for controlling.

The mask M includes a reticle on which a device pattern projected onto the substrate P is formed. The substrate P is a photosensitive substrate and includes, for example, a base material such as a glass plate and a photosensitive film (coated photosensitive material) formed on the base material. In the present embodiment, the substrate P includes a large glass plate, and the size of one side of the substrate P is, for example, 500 mm or more. In the present embodiment, a rectangular glass plate having a side of about 3000 mm is used as the base material of the substrate P.

In the present embodiment, the projection system PS has a plurality of projection optical systems. The illumination system IS has a plurality of illumination modules corresponding to a plurality of projection optical systems. Further, the exposure apparatus EX of the present embodiment projects an image of the pattern of the mask M onto the substrate P while moving the mask M and the substrate P synchronously in a predetermined scanning direction. That is, the exposure apparatus EX of the present embodiment is a so-called multi-lens scan exposure apparatus.

In the present embodiment, the projection system PS has seven projection optical systems PL1 to PL7, and the illumination system IS has seven illumination modules IL1 to IL7. The number of projection optical systems and illumination modules is not limited to seven. For example, the projection system PS may have 11 projection optical systems, and the illumination system IS may have 11 illumination modules.

In the following description, the projection optical systems PL1 to PL7 are appropriately referred to as first to seventh projection optical systems PL1 to PL7, respectively, and the illumination modules IL1 to IL7 are appropriately referred to as first to seventh illumination modules IL1 to IL7. Called IL7.

The illumination system IS can irradiate the exposure light EL to each of the seven different illumination areas IR1 to IR7. The illumination areas IR1 to IR7 correspond to irradiation areas irradiated with the exposure light EL emitted from the first to seventh illumination modules IL1 to IL7. In the following description, the illumination areas IR1 to IR7 are appropriately referred to as first to seventh illumination areas IR1 to IR7.

The illumination system IS illuminates each of the first to seventh illumination areas IR1 to IR7 with the exposure light EL. The illumination system IS illuminates a part of the mask M arranged in the first to seventh illumination regions IR1 to IR7 with the exposure light EL having a uniform illuminance distribution. In the present embodiment, bright lines (g line, h line, i line) emitted from the mercury lamp 5 are used as the exposure light EL emitted from the illumination system IS.

In the present embodiment, the illumination system IS includes an elliptic mirror 6 that reflects light emitted from the mercury lamp 5, a dichroic mirror 7 that reflects at least part of the light from the elliptic mirror 6, and light from the dichroic mirror 7. Includes a relay optical system 8 including a collimating lens and a condenser lens, and a light guide unit 9 that branches the light from the relay optical system 8 and supplies the light to each of the first to seventh illumination modules IL1 to IL7. I have.

Each of the first to seventh illumination modules IL1 to IL7 is supplied with a collimator lens to which light from the light guide unit 9 is supplied, a fly eye integrator to which light from the collimator lens is supplied, and light from the fly eye integrator. Equipped with a condenser lens. The exposure light EL emitted from the condenser lenses of the first to seventh illumination modules IL1 to IL7 is applied to the first to seventh illumination regions IR1 to IR7. Each of the first to seventh illumination modules IL1 to IL7 illuminates the first to seventh illumination regions IR1 to IR7 with the exposure light EL having a uniform illuminance distribution. The illumination system IS illuminates at least a part of the mask M arranged in the first to seventh illumination regions IR1 to IR7 with the exposure light EL having a uniform illuminance distribution.

The mask stage 1 has a mask holding unit 10 that can hold the mask M, and can move relative to the first to seventh illumination regions IR1 to IR7 while holding the mask M. In the present embodiment, the mask holding unit 10 holds the mask M so that the lower surface (pattern forming surface) of the mask M and the XY plane are substantially parallel. The mask stage 1 is movable by a driving force of a driving system including a linear motor, for example. In the present embodiment, the mask stage 1 can be moved in three directions of the X axis, the Y axis, and the θZ direction while the mask M is held by the mask holding unit 10 by the driving system.

Projection system PS can irradiate exposure light EL to seven different projection areas PR1 to PR7. The projection areas PR1 to PR7 correspond to irradiation areas irradiated with the exposure light EL emitted from the first to seventh projection optical systems PL1 to PL7. In the following description, the projection areas PR1 to PR7 are appropriately referred to as first to seventh projection areas PR1 to PR7.

The projection system PS projects an image of the pattern of the mask M on each of the first to seventh projection areas PR1 to PR7. The projection system PS projects an image of the pattern of the mask M on the part of the substrate P arranged in the first to seventh projection regions PR1 to PR7 with a predetermined projection magnification.

In the present embodiment, each of the first to seventh projection optical systems PL1 to PL7 includes a shift adjustment mechanism, a scaling adjustment mechanism, an image plane adjustment mechanism, and the like as disclosed in, for example, Japanese Patent No. 4211272. An image characteristic adjusting device is included. The control device 4 controls the image formation characteristic adjusting devices included in the first to seventh projection optical systems PL1 to PL7 to adjust the positions and sizes of the first to seventh projection regions PR1 to PR7. be able to.

The substrate stage 2 includes a substrate holder 11 that can hold the substrate P, and is movable relative to the first to seventh projection regions PR1 to PR7 while holding the substrate P. In the present embodiment, the substrate holding unit 11 holds the substrate P so that the surface (exposure surface) of the substrate P and the XY plane are substantially parallel. The substrate stage 2 is movable by a driving force of a driving system including a linear motor, for example. In the present embodiment, the substrate stage 2 is moved in six directions including the X axis, the Y axis, the Z axis, the θX, the θY, and the θZ directions in a state where the substrate P is held by the substrate holding unit 11 by the operation of the drive system. It is movable.

The interferometer system 3 optically measures the position of the first interferometer unit 3A capable of optically measuring the position of the mask stage 1 (mask M) in the XY plane and the position of the substrate stage 2 (substrate P) in the XY plane. And a second interferometer unit 3B capable of measuring. When executing the exposure process of the substrate P or when executing a predetermined measurement process, the control device 4 determines the mask stage 1 (mask M) and the substrate stage 2 (substrate P) based on the measurement result of the interferometer system 3. ) Position control is executed.

As described above, the exposure apparatus EX of the present embodiment is an exposure apparatus that projects the pattern image of the mask M onto the substrate P while moving the mask M and the substrate P in a predetermined scanning direction (multi-lens scan). Exposure apparatus). When the substrate P is exposed, the control device 4 controls the mask stage 1 and the substrate stage 2 to move the mask M and the substrate P in a predetermined scanning direction in the XY plane. In the present embodiment, the scanning direction (synchronous movement direction) of the substrate P is the X-axis direction, and the scanning direction (synchronous movement direction) of the mask M is also the X-axis direction. The control device 4 moves the substrate P in the X-axis direction with respect to the first to seventh projection regions PR1 to PR7 of the projection system PS, and synchronizes with the movement of the substrate P in the X-axis direction. While moving the mask M in the X-axis direction with respect to the first to seventh illumination regions IR1 to IR7 of IS, the illumination system IS illuminates the mask M with the exposure light EL, and from the mask M via the projection system PS. The substrate P is irradiated with the exposure light EL. Thereby, the substrate P is exposed with the exposure light EL from the mask M irradiated to the first to seventh projection regions PR1 to PR7 of the first to seventh projection optical systems PL1 to PL7, and an image of the pattern of the mask M is formed. Projected onto the substrate P.

FIG. 2 is a schematic diagram showing an example of the positional relationship between the first to seventh projection regions PR1 to PR7 and the substrate P, and shows the positional relationship in a plane including the surface of the substrate P. As shown in FIG. 2, in the present embodiment, each of the first to seventh projection regions PR1 to PR7 is trapezoidal in the XY plane. In the present embodiment, the first, third, fifth, and seventh projection regions PR1, PR3, PR5, and PR7 by the first, third, fifth, and seventh projection optical systems PL1, PL3, PL5, and PL7 are Y They are arranged at almost equal intervals in the axial direction. Further, the second, fourth, and sixth projection regions PR2, PR4, and PR6 by the second, fourth, and sixth projection optical systems PL2, PL4, and PL6 are arranged at substantially equal intervals in the Y-axis direction.

The first, third, fifth, and seventh projection regions PR1, PR3, PR5, and PR7 are disposed on the −X side with respect to the second, fourth, and sixth projection regions PR2, PR4, and PR6. Further, the second, fourth, and sixth projection regions PR2, PR4, and PR6 are disposed between the first, third, fifth, and seventh projection regions PR1, PR3, PR5, and PR7 with respect to the Y-axis direction. .

Each of the first to seventh projection regions PR1 to PR7 is arranged so that the integrated exposure amounts in the X-axis direction (scanning direction) on the substrate P are equal. The ends of the first to seventh projection regions PR1 to PR7 with respect to the Y-axis direction are arranged so as to overlap with each other with respect to the Y-axis direction, and the sum of the dimensions of the projection regions with respect to the X-axis direction is the same. It has been.

In the present embodiment, the end of the projection area refers to a triangular portion including an edge inclined with respect to the X axis in the trapezoidal projection area in the XY plane. In the following description, the rectangular part of the projection area other than the end part is appropriately referred to as a central part.

In the present embodiment, the + Y side end T1b of the first projection region PR1 and the −Y side end T2a of the second projection region PR2 are arranged so as to overlap with each other in the Y-axis direction. The + Y side end T2b of the second projection region PR2 and the −Y side end T3a of the third projection region PR3 are arranged so as to overlap in the Y-axis direction. The + Y side end T3b of the third projection region PR3 and the −Y side end T4a of the fourth projection region PR4 are arranged so as to overlap in the Y-axis direction. The + Y side end T4b of the fourth projection region PR4 and the −Y side end T5a of the fifth projection region PR5 are arranged so as to overlap in the Y-axis direction. The + Y side end T5b of the fifth projection region PR5 and the −Y side end T6a of the sixth projection region PR6 are arranged so as to overlap in the Y-axis direction. The + Y side end T6b of the sixth projection region PR6 and the −Y side end T7a of the seventh projection region PR7 are arranged so as to overlap in the Y-axis direction.

Regarding the X-axis direction, the sum of the dimension of the end T1b and the dimension of the end T2a, the sum of the dimension of the end T2b and the dimension of the end T3a, the dimension of the end T3b, and the dimension of the end T4a The sum of the sum, the size of the end T4b and the size of the end T5a, the sum of the size of the end T5b and the size of the end T6a, and the sum of the size of the end T6b and the size of the end T7a. Are almost the same.

Further, with respect to the X-axis direction, the size of the central portion C1 of the first projection region PR1, the size of the central portion C2 of the second projection region PR2, the size of the central portion C3 of the third projection region PR3, and the fourth projection region The dimensions of the central portion C4 of PR4, the dimensions of the central portion C5 of the fifth projection region PR5, the dimensions of the central portion C6 of the sixth projection region PR6, and the dimensions of the central portion C7 of the seventh projection region PR7 are substantially the same. The same.

Further, with respect to the X-axis direction, the dimension of the central part C1, and the sum of the dimension of the end part T1b and the dimension of the end part T2a are substantially the same. The dimensions of the other central part and the sum of the dimensions of the end parts have a similar relationship.

Thus, when the substrate P is exposed to the first to seventh projection regions PR1 to PR7 while moving in the X-axis direction, the integrated exposure amount in the X-axis direction on the substrate P becomes substantially the same.

In the following description, a portion where the projection areas overlap in the substrate P is appropriately referred to as an overlapping portion.

In the present embodiment, the overlapping portion B1 is provided on the substrate P by the first projection region PR1 and a part of the second projection region PR2. An overlapping portion B2 is provided on the substrate P by the second projection region PR2 and a part of the third projection region PR3. An overlapping portion B3 is provided on the substrate P by the third projection region PR3 and a part of the fourth projection region PR4. The overlapping portion B4 is provided on the substrate P by the fourth projection region PR4 and a part of the fifth projection region PR5. An overlapping portion B5 is provided on the substrate P by the fifth projection region PR5 and a part of the sixth projection region PR6. An overlapping portion B6 is provided on the substrate P by the sixth projection region PR6 and a part of the seventh projection region PR7.

At least a part of the substrate P disposed in the overlapping part B1 is subjected to overlapping exposure by the first projection area PR1 and a part of the second projection area PR2. At least a part of the substrate P arranged in the overlapping part B2 is subjected to overlapping exposure by the second projection region PR2 and a part of the third projection region PR3. At least a part of the substrate P arranged in the overlapping part B3 is subjected to overlapping exposure by the third projection region PR3 and a part of the fourth projection region PR4. At least a part of the substrate P arranged in the overlapping part B4 is subjected to overlapping exposure by the fourth projection region PR4 and a part of the fifth projection region PR5. At least a part of the substrate P arranged in the overlapping part B5 is subjected to overlapping exposure by the fifth projection region PR5 and a part of the sixth projection region PR6. At least a part of the substrate P disposed in the overlapping part B6 is subjected to overlapping exposure by the sixth projection region PR6 and a part of the seventh projection region PR7. When performing exposure of the substrate P, the first to seventh projection regions PR1 to PR7 are irradiated with the exposure light EL in a state where the substrate P is disposed on at least a part of the first to seventh projection regions PR1 to PR7. Is done.

Next, an example of the operation of the exposure apparatus EX will be described.

In the present embodiment, the exposure apparatus EX is connected to a coater / developer apparatus including a coating apparatus for forming a photosensitive film on the base material of the substrate P and a developer apparatus for developing the exposed substrate P. The photosensitive substrate P on which the photosensitive film is formed in the coater / developer apparatus is carried into the exposure apparatus EX by a predetermined transport apparatus.

Note that, as described above, the base material of the substrate P includes a glass plate. In the following description, for simplicity of explanation, the base material is a glass plate, and a case where a photosensitive film is formed on the glass plate will be described as an example. However, the surface (base) of the base material is anti-reflective. It may be a membrane. Moreover, the surface (base) of the base material may be a part of, for example, a thin film transistor formed on a glass plate by the previous process. For example, the surface (base) of the base material is an oxide film such as SiO ₂ formed by the previous process, an insulating film such as SiO ₂ and SiN _x , a conductor film (metal film) such as Cu or ITO, amorphous Si, etc. In some cases, the surface is at least one surface of a semiconductor film.

After the substrate P before exposure is carried into the exposure apparatus EX and held on the substrate stage 2, the control apparatus 4 starts exposure of the substrate P. In the exposure of the substrate P, the substrate P is moved in the scanning direction (X-axis direction) along the surface (XY plane) of the substrate P with respect to the first to seventh projection regions PR1 to PR7, and the mask M is moved to the first. Executed while moving in the scanning direction (X-axis direction) along the lower surface (XY plane) of the mask M with respect to the seventh illumination regions IR1 to IR7.

After the exposure, the substrate P is unloaded from the substrate stage 2 and then transferred to the coater / developer apparatus and developed. As a result, a pattern of the photosensitive film (exposure pattern layer) is formed on the substrate P. Thereafter, a pattern (device pattern) is formed on the substrate P by performing a predetermined process such as an etching process.

By the way, as described above, when the substrate P is exposed to the first to seventh projection regions PR1 to PR7 while moving in the X-axis direction, the integrated exposure amount in the X-axis direction on the substrate P becomes the same. That is, with respect to the X-axis direction, the first to seventh projection regions PR1 to PR7 are set so that the center size of the first to seventh projection regions PR1 to PR7 is the same as the sum of the sizes of the end portions. Each shape, size, and positional relationship between the first to seventh projection regions PR1 to PR7 are determined. In other words, the first to seventh projection regions PR1 to PR7 overlap each other (B1 to B6) and the non-overlapping non-overlapping portions have the same accumulated exposure amount on the substrate P. The shape and size of each of the seventh projection areas PR1 to PR7 and the positional relationship between the first to seventh projection areas PR1 to PR7 are determined.

FIG. 3 shows an example in which the positional relationship between the first projection region PR1 and the second projection region PR2 is an ideal state (target state) among the first to seventh projection regions PR1 to PR7. It is a schematic diagram.

Here, the ideal state is a state in which the integrated exposure amount in the X-axis direction (scanning direction) of the exposure light EL irradiated to the projection areas (PR1, PR2) adjacent to each other in the Y-axis direction is equal, that is, The sum of the dimension of one projection area (PR1) and the dimension of the other projection area (PR2) in the X-axis direction at the overlapping portion between the projection area (PR1) and the other projection area (PR2) is non-overlapping This means that the dimensions of the projection areas (PR1, PR2) of one and the other in the part are the same.

In FIG. 3, the overlapping part B1 is formed only by the end part T1b and the end part T2a. The non-overlapping part A1 is formed only by the central part C1. The non-overlapping part A2 is formed only by the central part C2. In the example shown in FIG. 3, the integrated exposure amount in the overlapping portion B1, the integrated exposure amount in the non-overlapping portion A1 (center portion C1), and the integrated exposure amount in the non-overlapping portion A2 (center portion C2) are the same. is there. In this case, the dimension of the pattern formed on the substrate P by the exposure light EL irradiated to the central portion C1 of the first projection region PR1 that forms the non-overlapping portion A1, and the second projection region PR2 that forms the non-overlapping portion A2. The dimension of the pattern formed on the substrate P by the exposure light EL irradiated to the central portion C2 of the substrate and the substrate P by the exposure light EL irradiated to the overlapping portion B1 between the first projection region PR1 and the second projection region PR2. The dimensions of the pattern to be formed are almost the same.

FIG. 4 is a schematic diagram showing an example of a state in which the positional relationship between the first projection region PR1 and the second projection region PR2 is deviated from the ideal state among the first to seventh projection regions PR1 to PR7. It is.

In FIG. 4, the first projection region PR1 and the second projection region PR2 are close to each other as compared to the ideal state, but may be separated.

Here, in the following description, a state where the projection regions (PR1, PR2) are deviated from the ideal state is appropriately referred to as a joint displacement state, and a deviation amount from the ideal state is appropriately referred to as a deviation amount.

In FIG. 4, the overlapping part B1 is formed by a part of the center part C1, an end part T1b, a part of the center part C2, and an end part T2a. The non-overlapping part A1 is formed by a part of the central part C1. The non-overlapping part A2 is formed by a part of the central part C2. In the example shown in FIG. 4, the integrated exposure amount in the overlapping portion B1 is different from the integrated exposure amount in the non-overlapping portions A1 and A2. In this case, the dimension of the pattern formed on the substrate P by the exposure light EL irradiated to the central portion C1 of the first projection region PR1 that forms the non-overlapping portion A1, and the second projection region PR2 that forms the non-overlapping portion A2. The dimension of the pattern formed on the substrate P by the exposure light EL irradiated to the central portion C2 of the substrate and the substrate P by the exposure light EL irradiated to the overlapping portion B1 between the first projection region PR1 and the second projection region PR2. The dimension of the pattern to be formed is different.

In the example shown in FIG. 4, the pattern formed on the substrate P becomes non-uniform, and a defective device may occur.

Therefore, in the present embodiment, for example, as shown in FIG. 4, even when the positional relationship between adjacent projection regions deviates from the ideal state, a process including exposure conditions and development conditions that can prevent the pattern from becoming non-uniform. Conditions are predetermined. Then, an exposure process and a development process for manufacturing a device on the substrate P are executed based on the determined process conditions.

In the present embodiment, the exposure conditions include the integrated exposure amount of the exposure light EL that is irradiated onto the projection area where the substrate P is disposed. The development conditions include the development time of the substrate P irradiated with the exposure light EL (the time during which the developer and the photosensitive film of the substrate P are in contact), the type (physical properties) of the developer to be used, and the like.

In the following description, a predetermined exposure condition that can prevent the pattern from becoming nonuniform is referred to as an optimal integrated exposure amount as appropriate, and the pattern can be suppressed from becoming nonuniform and the pattern can be set to a desired dimension. The predetermined development conditions that can be obtained are appropriately referred to as optimum development time.

That is, the predetermined exposure condition includes an integrated exposure amount at which the dimension of the pattern formed on the substrate P becomes uniform. In the present embodiment, the integrated exposure amount is determined by the dimension of the pattern formed on the substrate P by the exposure light EL irradiated to the non-overlapping portion A1 of the first projection region PR1, and the non-overlapping portion A2 of the second projection region PR2. The dimension of the pattern formed on the substrate P by the exposure light EL irradiated on the substrate and the pattern formed on the substrate P by the exposure light EL irradiated on the overlapping portion B1 between the first projection region PR1 and the second projection region PR2. The integrated exposure amount in the first projection region PR1 and the second projection region PR2 that substantially coincide with each other is included. The predetermined development conditions include a development time in which the dimension of the pattern formed on the substrate P is a target value.

Hereinafter, with reference to FIGS. 5 to 12, the optimum integrated exposure amount and the optimum development time that can make the pattern uniform on the substrate P will be described. In the following description, the non-overlapping portion A1 of the first projection region PR1 (or the non-overlapping portion A2 of the second projection region PR2) and the overlapping portion B1 of the first projection region PR1 and the second projection region PR2 will be described. However, the same applies to the non-overlapping portions of the other projection regions (PR2 to PR7) and the overlapping portions of the other projection regions (PR3 to PR7).

5 to 9 and 11 are schematic diagrams showing the relationship between the pattern of the mask M and the integrated exposure amount in the projection area where the substrate P is arranged. The pattern of the mask M is a line and space pattern, and a transmission part (space part) 21 that transmits the exposure light EL from the illumination system IS and a light shielding part (line part) that blocks the exposure light EL from the illumination system IS. ) 22.

The substrate P has a photosensitive film. In this embodiment, the photosensitive film of the substrate P is a so-called positive type in which a portion irradiated with the exposure light EL is removed by development. By irradiating the substrate P with the exposure light EL from the mask M and developing, a pattern (line and space pattern) corresponding to the pattern of the mask M is formed on the substrate P (photosensitive film). The target dimension (target line width) of the pattern (line pattern) formed on the substrate P is WT. 5 and the like, the dimension of the line portion 22 of the mask M and the target dimension WT of the pattern formed on the substrate P are shown to be the same, but the dimension of the line portion 22 and the target dimension WT The relationship (ratio) varies depending on, for example, the projection magnification of the projection optical system. In the graphs shown in FIGS. 5 to 9 and FIG. 11, the horizontal axis indicates the position of the surface of the substrate P, and the vertical axis indicates the value of the integrated exposure amount in the projection area.

FIG. 5 shows the pattern of the mask M and the exposure light EL from the mask M irradiated to the central portion C1 (non-overlapping portion A1) of the first projection region PR1 of the first projection optical system PL1 in the central portion C1. It is a schematic diagram which shows the relationship with distribution of integrated exposure amount. In the graph shown in FIG. 5, a line LC1 indicates the distribution of the integrated exposure amount in the central portion C1. The value of the integrated exposure amount corresponding to the space portion 21 is Jh.

FIG. 6 shows the relationship between the pattern of the mask M and the distribution of the integrated exposure amount when the substrate P is subjected to overlapping exposure when the positional relationship between the first projection region PR1 and the second projection region PR2 is an ideal state. It is a schematic diagram shown. In the graph shown in FIG. 6, the line L1b shows an example of the distribution of the integrated exposure amount at the end T1b where the substrate P is arranged, and the line L2a is the distribution of the integrated exposure amount at the end T2a where the substrate P is arranged. An example is shown. A line LB1a indicates the sum of the integrated exposure amount indicated by the line L1b and the integrated exposure amount indicated by the line L2a, that is, the distribution of the integrated exposure amount in the overlapping portion B1 where the substrate P is disposed.

Since the positional relationship between the first projection region PR1 and the second projection region PR2 is an ideal state, on the substrate P, the distribution of the integrated exposure amount at the end T1b and the distribution of the integrated exposure amount at the end T2a coincide. Further, since the positional relationship between the first projection region PR1 and the second projection region PR2 is an ideal state, the distribution of the integrated exposure amount in the central portion C1 (non-overlapping portion A1) shown in FIG. 5 and the overlapping portion shown in FIG. The distribution of the integrated exposure amount in B1 matches.

FIG. 7 shows the relationship between the pattern of the mask M and the distribution of the integrated exposure amount when the substrate P is subjected to overlapping exposure when the positional relationship between the first projection region PR1 and the second projection region PR2 is a joint displacement state. It is a schematic diagram which shows. In the graph shown in FIG. 7, the line L1b shows an example of the distribution of the integrated exposure amount at the end T1b where the substrate P is disposed, and the line L2a is the distribution of the integrated exposure amount at the end T2a where the substrate P is disposed. An example is shown. A line LB1b indicates the sum of the integrated exposure amount indicated by the line L1b and the integrated exposure amount indicated by the line L2a, that is, the distribution of the integrated exposure amount in the overlapping portion B1 where the substrate P is disposed.

Since the positional relationship between the first projection region PR1 and the second projection region PR2 is in a jointly shifted state, on the substrate P, the distribution of the integrated exposure amount at the end portion T1b and the distribution of the integrated exposure amount at the end portion T2a deviate.

Further, since the positional relationship between the first projection region PR1 and the second projection region PR2 is in a jointly shifted state, the distribution of the integrated exposure amount in the central portion C1 (non-overlapping portion A1) and the overlapping portion B1 shown in FIGS. The value and the distribution and value of the integrated exposure amount in the overlapping portion B1 shown in FIG. 7 are different.

FIG. 8 shows the relationship between the pattern of the mask M and the distribution of the integrated exposure amount when the substrate P is subjected to overlapping exposure when the positional relationship between the first projection region PR1 and the second projection region PR2 is a joint displacement state. It is a schematic diagram which shows. The deviation amount in the example shown in FIG. 8 is larger than the deviation amount in the example shown in FIG. In the graph shown in FIG. 8, the line L1b shows an example of the distribution of the integrated exposure amount at the end T1b where the substrate P is disposed, and the line L2a is the distribution of the integrated exposure amount at the end T2a where the substrate P is disposed. An example is shown. A line LB1c indicates the sum of the integrated exposure amount indicated by the line L1b and the integrated exposure amount indicated by the line L2a, that is, the distribution of the integrated exposure amount in the overlapping portion B1 where the substrate P is disposed.

Since the positional relationship between the first projection region PR1 and the second projection region PR2 is a joint displacement state, and the displacement amount is larger than the example shown in FIG. 7, the distribution of the integrated exposure amount at the end T1b in the substrate P. And the distribution of the integrated exposure amount at the end T2a is greatly different from the example shown in FIG.

Further, since the positional relationship between the first projection region PR1 and the second projection region PR2 is in a jointly shifted state, the integrated exposure at the central portion C1 (non-overlapping portion A1) and the overlapping portion B1 shown in FIGS. The distribution and value of the amount are different from the distribution and value of the integrated exposure amount in the overlapping portion B1 shown in FIG.

FIG. 9 shows the lines LB1a, LB1b, and LB1c shown in FIGS. 5 to 8 in one graph. As shown in FIG. 9, there is a value Jk in which the integrated exposure amount in the ideal state and the integrated exposure amount in the joint shift state coincide. That is, by setting the integrated exposure amount in the non-overlapping portion A1 to the value Jh, the integrated exposure amount in the non-overlapping portion A1 and the integrated exposure amount in the overlapping portion B1 in the ideal state and the joint displacement state are values Jk. Match.

Accordingly, as the photosensitive film used for the substrate P, when the integrated exposure amount of the exposure light EL is greater than or equal to the value Jk, it is removed by development, and when it is less than the value Jk, it remains on the substrate P even after development (the pattern is changed). The photosensitive film formed on the substrate P by the exposure light EL irradiated to the non-overlapping portion A1 in each of the ideal state and the joint shift state by using the photosensitive film having characteristics (photosensitive characteristics, solubility). And the dimension of the pattern of the photosensitive film formed on the substrate P by the exposure light EL irradiated to the overlapping portion B1 can be matched.

FIG. 10 shows that the first projection region PR1 and the second projection region PR2 are irradiated with the exposure light EL and then the exposure light EL is irradiated so that the integrated exposure amount in the non-overlapping portions A1 and A2 becomes the value Jh. A pattern of a photosensitive film formed on the substrate P by developing the substrate P is shown. In FIG. 10, the line Ra is an ideal state as described with reference to FIG. 6, and when the substrate P is subjected to overlapping exposure so that the integrated exposure amount in the non-overlapping portions A <b> 1 and A <b> 2 becomes the value Jh. The outline (outer shape) of the pattern of the photosensitive film after development is shown. The line Rb is a state after development in the case where the substrate P is overlapped and exposed so that the integrated exposure amount in the non-overlapping portions A1 and A2 becomes the value Jh as described with reference to FIG. The outline (outer shape) of the pattern of the photosensitive film is shown. The line Rc indicates a photosensitive film after development when the substrate P is overlapped and exposed so that the accumulated exposure amount in the non-overlapping portion A1 becomes the value Jh as described with reference to FIG. The outline (outer shape) of the pattern is shown.

When the photosensitive film of the substrate P is a positive type and has a photosensitive characteristic (solubility) that is removed by development when the integrated exposure amount of the irradiated exposure light EL is equal to or greater than the value Jk, the value corresponding to the value Jk By irradiating the photosensitive film having photosensitive characteristics with the exposure light EL so that the integrated exposure amount at the non-overlapping portions A1 and A2 becomes the value Jh, the dimension of the pattern after development of the photosensitive film exposed in an ideal state And the dimension of the pattern after development of the photosensitive film exposed in the joint misalignment state can be matched. In the example shown in FIG. 10, the dimension of the pattern after development of the photosensitive film exposed in the ideal state and the dimension of the pattern after development of the photosensitive film exposed in the joint displacement state coincide with each other with the value Wa. Yes.

The dimension of the photosensitive film pattern is the width (line width) of the photosensitive film pattern formed in a line shape on the substrate P in accordance with the line and space pattern of the mask M. The width. In the present embodiment, the bottom width refers to the distance between the intersection between the surface of the substrate and one side surface of the photosensitive film and the intersection between the surface of the substrate and the other side surface of the photosensitive film.

As described above, the integrated exposure value Jh in the non-overlapping portions A1 and A2 is determined according to the photosensitive characteristic (solubility) of the substrate P (photosensitive film), and the integrated exposure amount in the non-overlapping portions A1 and A2 is the value Jh. By irradiating the first projection region PR1 and the second projection region PR2 with the exposure light EL, a pattern having the same dimension Wa is formed on the substrate P in each of the ideal state and the joint displacement state. The

That is, even when the joint is shifted, the size of the pattern formed on the substrate P by the exposure light EL irradiated to the non-overlapping portions A1 and A2 and the substrate P by the exposure light EL irradiated to the overlapping portion B1. The dimensions of the pattern formed in the same are the same. Therefore, it is possible to prevent the pattern formed on the substrate P from becoming non-uniform.

FIG. 11 shows distributions of the integrated exposure amounts in the ideal state and the joint displacement state when the values of the integrated exposure amounts in the non-overlapping portions A1 and A2 are changed. Line LP1a shows an ideal state where the value of the integrated exposure amount of non-overlapping portions A1 and A2 (center portions C1 and C2) is Jh1, and line LP1b is a splice state and non-overlapping. The case where the value of the integrated exposure amount of the parts A1 and A2 (center parts C1 and C2) is Jh1 is shown. The line LQ1a is an ideal state, and shows the case where the value of the integrated exposure amount of the non-overlapping portions A1 and A2 (center portions C1 and C2) is Jh2 different from Jh1, and the line LQ1b is in a joint shift state The case where the value of the integrated exposure amount of the non-overlapping portions A1 and A2 (center portions C1 and C2) is Jh2 is shown. Line LR1a shows an ideal state where the value of the integrated exposure amount of non-overlapping parts A1 and A2 (center parts C1 and C2) is Jh3 different from Jh1 and Jh2, and line LR1b shows a joint-shifted state. In this case, the value of the integrated exposure amount of the non-overlapping portions A1 and A2 (center portions C1 and C2) is Jh3.

As shown in FIG. 11, even when the value of the integrated exposure amount in the non-overlapping portion A1 changes to the values Jh1, Jh2, and Jh3, the value that the integrated exposure amount in the ideal state and the integrated exposure amount in the joint shift state coincide with each other. Jk1, Jk2, and Jk3 exist. Thereby, according to the photosensitive characteristic of the substrate P (photosensitive film), for example, an optimum value is determined from the values Jh1, Jh2, and Jh3, thereby making the pattern formed on the substrate P after development uniform. be able to.

For example, when the photosensitive film of the substrate P has a photosensitive characteristic that is removed by development when the integrated exposure amount of the irradiated exposure light EL is equal to or greater than the value Jk1, the non-overlapping portions A1, A2 (center portions C1, C2) The value Jh1 is determined as the integrated exposure amount in (). Similarly, when the photosensitive film of the substrate P has a photosensitive characteristic that is removed by development when the integrated exposure amount of the irradiated exposure light EL is equal to or greater than the value Jk2, the non-overlapping portions A1, A2 (center portion C1, The value Jh2 is determined as the integrated exposure amount in C2). Further, when the photosensitive film of the substrate P has a photosensitive characteristic that is removed by development when the integrated exposure amount of the irradiated exposure light EL is equal to or greater than the value Jk3, the non-overlapping portions A1, A2 (center portions C1, C2) The value Jh3 is determined as the integrated exposure amount in ().

Thus, the integrated exposure amount Jh that can make the pattern dimension uniform on the substrate P is determined according to the photosensitive characteristics of the substrate P.

In the following description, the integrated exposure amount at the non-overlapping portion (center portion) that can prevent the pattern from becoming non-uniform on the substrate P is appropriately referred to as an optimal integrated exposure amount JOPT.

Incidentally, the dimension Wa of the pattern shown in FIG. 10 is different from the target dimension WT. That is, in the substrate P, the pattern dimension Wa is uniform, but the dimension Wa is different from the target dimension WT. Therefore, in the present embodiment, by adjusting the development time T, the dimension of the pattern of the substrate P (photosensitive film pattern) is set to the target dimension WT.

FIG. 12 is a schematic diagram showing a state in which the dimension of the pattern is adjusted according to the development time T. In the development process, the contour (outer shape) of the photosensitive film changes isotropically. That is, as shown by the arrow in FIG. 12, the dimension of the photosensitive film isotropically decreases by the development process. Therefore, by adjusting the developing time T, the pattern of the photosensitive film having the dimension Wa can be changed to the pattern of the photosensitive film having the dimension WT.

In the following description, the development time during which the dimension Wa of the pattern uniformly formed on the substrate P can be set to the target dimension WT is appropriately referred to as optimum development time TOPT.

As described above, the optimum integrated exposure amount JOPT corresponding to the predetermined exposure condition and the optimum development time TOPT corresponding to the predetermined development condition have been described with reference to FIGS.

Hereinafter, an example of a pattern forming method including a method for determining the optimum integrated exposure amount JOPT and the optimum developing time TOPT will be described.

In the pattern forming method according to the present embodiment, as shown in the flowchart of FIG. 13, a predetermined exposure condition (optimum integrated exposure amount JOPT) and a predetermined development condition (optimal development time TOPT) that can prevent the pattern from becoming non-uniform. ) Is determined (step SP1), the substrate P is exposed under the determined predetermined exposure condition (optimum integrated exposure amount JOPT), and the substrate P is determined under the determined predetermined development condition (optimum development time TOPT). (Step SP2).

In step SP1, in order to determine a predetermined exposure condition (optimum integrated exposure amount JOPT) and a predetermined development condition (optimum development time TOPT), a process of exposing the substrate and a process of developing the exposed substrate are performed. Executed. In step SP2, in order to form a device (device pattern) on the substrate P, a process of exposing the substrate under the determined predetermined exposure conditions and a process of developing the substrate under the determined predetermined development conditions are performed. Executed.

In the following description, in order to determine the optimum integrated exposure amount JOPT and the optimum development time TOPT, the exposure performed in step SP1 is appropriately referred to as test exposure, and the development performed in step SP1 is appropriately performed as test development. Called. Further, the substrate used in step SP1 is appropriately referred to as a test substrate Pt. In order to form a device pattern, the exposure executed in step SP2 is appropriately referred to as main exposure, and the development executed in step SP2 is appropriately referred to as main development.

In the present embodiment, step SP1 includes test exposure of the test substrate Pt with the exposure light EL from the mask M irradiated onto the projection area of the projection optical system under different exposure conditions, and different developments. Based on the test development of the test substrate Pt subjected to the test exposure under each of the conditions, and the pattern formed on the test substrate Pt by the test exposure and the test development, the predetermined exposure condition (optimum integrated exposure amount JOPT) and the predetermined Determining development conditions (optimum development time TOPT).

In this embodiment, in step SP2, the substrate P is exposed with the exposure light EL from the mask M irradiated onto the projection area of the projection optical system under the predetermined exposure condition (optimum integrated exposure amount JOPT) determined in step SP1. And exposing the substrate P subjected to the main exposure under the predetermined development condition (optimum development time TOPT) determined in step SP1.

Hereinafter, a case where the test exposure is performed using the first projection optical system PL1 among the first to seventh projection optical systems PL1 to PL7 will be described as an example of the test exposure. Note that the test exposure may be performed using at least one of the second to seventh projection optical systems PL2 to PL7 other than the first projection optical system PL1. In the following description, the first projection optical system PL1 is appropriately referred to as a projection optical system PL, and the first projection region PR1 of the first projection optical system PL1 is appropriately referred to as a projection region PR.

In the test exposure, the projection region PR where the test substrate Pt is arranged is irradiated with the exposure light EL a plurality of times, and the test substrate Pt is subjected to overlapping exposure. In the following description, a portion where the test substrate Pt is subjected to overlapping exposure is appropriately referred to as an overlapping portion. In the present embodiment, the first test substrate Pt1 and the second test substrate Pt2 are used as the test substrate Pt.

In the present embodiment, the test exposure is performed from the mask M irradiated to the projection region PR so that the accumulated exposure amount in the projection region PR of the projection optical system PL becomes the first value Ja as shown in the flowchart of FIG. Exposing the first area AR1 of the first test substrate Pt1 with the exposure light EL (step SA1), and the projection area PR so that the integrated exposure amount at the overlapping portion of the projection area PR becomes the first value Ja. Multiple exposure of the second area AR2 of the first test substrate Pt1 with the exposure light EL from the mask M irradiated to the projection area PR at each of a plurality of different positions (step SA2), and integration in the projection area PR The third area AR3 of the first test substrate Pt1 with the exposure light EL from the mask M irradiated to the projection area PR so that the exposure amount becomes a second value Jb different from the first value Ja. The projection region PR was irradiated at each of a plurality of different positions with respect to the projection region PR so that the exposure (step SA3) and the integrated exposure amount at the overlapping portion of the projection region PR become the second value Jb. Overexposure is performed on the fourth area AR4 of the first test substrate Pt1 with the exposure light EL from the mask M (step SA4), and the integrated exposure amount in the projection area PR of the projection optical system PL becomes the first value Ja. Then, exposing the fifth area AR5 of the second test substrate Pt2 with the exposure light EL from the mask M irradiated to the projection area PR (step SA5), and the integrated exposure amount in the overlapping area of the projection area PR is the first value. The sixth region A of the second test substrate Pt2 is exposed to the exposure light EL from the mask M irradiated to the projection region PR at each of a plurality of positions different from the projection region PR so as to be Ja. Comprising 6 to overlapping exposure (step SA6), the.

In the present embodiment, as shown in the flowchart of FIG. 15, the test development is performed by developing the first test substrate Pt1 on which the first to fourth areas AR1 to AR4 are exposed for the first time Ta, A photosensitive film pattern is formed in each of the first to fourth areas AR1 to AR4 of Pt1 (step SB1), and the second test substrate Pt2 on which the fifth and sixth areas AR5 and AR6 are exposed is formed on the first test substrate Pt2. Developing at a second time Tb different from the time Ta to form a pattern of a photosensitive film in each of the fifth and sixth regions AR5 and AR6 of the second test substrate Pt2 (step SB2).

In the following description, the pattern of the photosensitive film formed in the first area AR1 after the test development is appropriately referred to as a first pattern. Similarly, after the test development, the pattern of the photosensitive film formed in each of the second, third, fourth, fifth and sixth regions AR2, AR3, AR4, AR5, AR6 is appropriately changed to the second, third, third, These are called fourth, fifth and sixth patterns.

FIG. 16 is a schematic diagram illustrating an example of the first test substrate Pt1, and FIG. 17 is a schematic diagram illustrating an example of the second test substrate Pt2. In FIGS. 16 and 17, the shape of the projection region PR is a rectangle.

In the present embodiment, as shown in FIG. 16, the first test substrate Pt1 is exposed with the exposure light EL from the mask M irradiated to the projection region PR so that the integrated exposure amount in the projection region PR becomes the first value Ja. The first area AR1 is exposed (step SA1).

In the present embodiment, when the first area AR1 is exposed, the integrated exposure amount in the projection area PR becomes the first value Ja while the position of the first test substrate Pt1 with respect to the projection area PR is fixed. Overlap exposure is performed. That is, in the ideal state, the first area AR1 is subjected to overlapping exposure so that the integrated exposure amount in the projection area PR becomes the first value Ja. For example, the exposure light EL from the mask M is irradiated onto the projection region PR so that the exposure amount in the projection region PR becomes 1 / H1 of the first value Ja, and the position of the first test substrate Pt1 is fixed. H1 overlap exposure is executed. In addition, when performing overlapping exposure, the exposure amount in each exposure may be different. Further, the exposure light EL from the mask M is irradiated to the projection region PR so that the exposure amount in the projection region PR becomes the first value Ja, and the exposure is performed only once in a state where the position of the first test substrate Pt1 is fixed. (Single exposure) may be used.

The second exposure AR2 of the first test substrate Pt1 is subjected to overlapped exposure in a joint shift state (step SA2). As shown in FIG. 16, in the present embodiment, the projection region PR is at each of two different positions with respect to the projection region PR so that the integrated exposure amount at the overlapping portion of the projection region PR becomes the first value Ja. The second area AR2 of the first test substrate Pt1 is subjected to overlapping exposure with the exposure light EL from the mask M irradiated on the surface.

When the second area AR2 is exposed, the projection area PR is irradiated with the exposure light EL from the mask M so that the exposure amount in the projection area PR is ½ of the first value Ja, and is arranged in the projection area PR. The second area AR2 of the first test substrate Pt1 is exposed at each of two different positions with respect to the projection area PR, and is exposed twice. In the present embodiment, of the two overlapping exposures, the distance (deviation) between the position of the substrate P relative to the projection region PR in the first exposure and the position of the substrate P relative to the projection region PR in the second exposure. The amount is, for example, 2 μm.

Note that the overlap exposure is not limited to two times, and can be executed any number of times three or more. For example, when overlapped exposure is executed H2 times, the exposure amount in the projection region PR in one exposure is set to 1 / H2 of the first value Ja. In addition, when performing overlapping exposure, the exposure amount in each exposure may be different.

In addition, the third area AR3 of the first test substrate Pt1 is exposed with the exposure light EL from the mask M irradiated on the projection area PR so that the integrated exposure amount in the projection area PR becomes the second value Jb (step). SA3). The second value Jb is different from the first value Ja. In the present embodiment, the second value Jb is, for example, 1.2 times the first value Ja.

In the present embodiment, when the third area AR3 is exposed, the integrated exposure amount in the projection area PR becomes the second value Jb in a state where the position of the first test substrate Pt1 with respect to the projection area PR is fixed. Overlap exposure is performed. That is, in the ideal state, the third area AR3 is subjected to overlapping exposure so that the integrated exposure amount in the projection area PR becomes the second value Jb. For example, the exposure light EL from the mask M is irradiated onto the projection region PR so that the exposure amount in the projection region PR becomes 1 / H3 of the second value Jb, and the position of the first test substrate Pt1 is fixed. Overlap exposure is executed H3 times. In addition, when performing overlapping exposure, the exposure amount in each exposure may be different. Further, the exposure light EL from the mask M is irradiated to the projection region PR so that the exposure amount in the projection region PR becomes the second value Jb, and the exposure is performed only once in a state where the position of the first test substrate Pt1 is fixed. (Single exposure) may be used.

Overlap exposure is performed in a joint shift state on the fourth area AR4 of the first test substrate Pt1 (step SA4). As shown in FIG. 16, in the present embodiment, the projection region PR is at each of two different positions with respect to the projection region PR so that the integrated exposure amount at the overlapping portion of the projection region PR becomes the second value Jb. The fourth area AR4 of the first test substrate Pt1 is subjected to overlapping exposure with the exposure light EL from the mask M irradiated on the surface.

When the fourth area AR4 is exposed, the projection area PR is irradiated with the exposure light EL from the mask M so that the exposure amount in the projection area PR is ½ of the second value Jb, and is arranged in the projection area PR. The fourth area AR4 of the first test substrate Pt1 is exposed at each of two different positions with respect to the projection area PR, and is exposed twice. In the present embodiment, of the two overlapping exposures, the distance (deviation) between the position of the substrate P relative to the projection region PR in the first exposure and the position of the substrate P relative to the projection region PR in the second exposure. The amount is, for example, 2 μm.

Note that the overlap exposure is not limited to two times, and can be executed any number of times three or more. For example, when overlap exposure is performed H4 times, the exposure amount in the projection region PR in one exposure is set to 1 / H4 of the first value Ja. In addition, when performing overlapping exposure, the exposure amount in each exposure may be different.

Further, as shown in FIG. 17, the fifth region of the second test substrate Pt2 is exposed with the exposure light EL from the mask M irradiated on the projection region PR so that the integrated exposure amount in the projection region PR becomes the first value Ja. AR5 is exposed (step SA5).

In the present embodiment, when the fifth area AR5 is exposed, the integrated exposure amount in the projection area PR becomes the first value Ja while the position of the second test substrate Pt2 with respect to the projection area PR is fixed. Overlap exposure is performed. That is, in the ideal state, the fifth area AR5 is subjected to overlapping exposure so that the integrated exposure amount in the projection area PR becomes the first value Ja. For example, the exposure light EL from the mask M is irradiated onto the projection region PR so that the exposure amount in the projection region PR becomes 1 / H5 of the first value Ja, and the position of the second test substrate Pt2 is fixed. Overlap exposure is performed H5 times. In addition, when performing overlapping exposure, the exposure amount in each exposure may be different. Further, the exposure light EL from the mask M is irradiated to the projection region PR so that the exposure amount in the projection region PR becomes the first value Ja, and the exposure is performed only once in a state where the position of the first test substrate Pt1 is fixed. (Single exposure) may be used.

Overlap exposure is performed on the sixth area AR6 of the second test substrate Pt2 in a joint shift state (step SA6). As shown in FIG. 17, in the present embodiment, the projection region PR is at each of two different positions with respect to the projection region PR so that the integrated exposure amount at the overlapping portion of the projection region PR becomes the first value Ja. The sixth area AR6 of the second test substrate Pt2 is subjected to overlapping exposure with the exposure light EL from the mask M irradiated on the surface.

When the sixth area AR6 is exposed, the projection area PR is irradiated with the exposure light EL from the mask M so that the exposure amount in the projection area PR is ½ of the first value Ja, and is arranged in the projection area PR. The sixth area AR6 of the second test substrate Pt2 is exposed at each of two different positions with respect to the projection area PR, and is exposed twice. In the present embodiment, of the two overlapping exposures, the distance (deviation) between the position of the substrate P relative to the projection region PR in the first exposure and the position of the substrate P relative to the projection region PR in the second exposure. The amount is, for example, 2 μm.

Note that the overlap exposure is not limited to two times, and can be executed any number of times three or more. For example, when overlapping exposure is performed H6 times, the exposure amount in the projection region PR in one exposure is set to 1 / H6 of the first value Ja. In addition, when performing overlapping exposure, the exposure amount in each exposure may be different.

Next, development processing is performed on the first test substrate Pt1 (step SB1). The development time of the first test substrate Pt1 is the first time Ta.

Further, development processing is performed on the second test substrate Pt2 (step SB2). The development time of the second test substrate Pt2 is the second time Tb. The first time Ta and the second time Tb are different. In the present embodiment, the second time Tb is 0.8 times the first time Ta.

By performing development on the first and second test substrates Pt1 and Pt2, a first pattern of the photosensitive film is formed in the first area AR1, and a second pattern of the photosensitive film is formed in the second area AR2. A third pattern of the photosensitive film is formed in the third area AR3, a fourth pattern of the photosensitive film is formed in the fourth area AR4, and a fifth pattern of the photosensitive film is formed in the fifth area AR5. A sixth pattern of the photosensitive film is formed in the six area AR6. Each of the first to sixth patterns is a line pattern.

Next, in the present embodiment, the dimensions (bottom width) of the first pattern, the second pattern, the third pattern, the fourth pattern, the fifth pattern, and the sixth pattern are measured. The measurement of the dimension (bottom width) of the pattern is performed using a predetermined measuring device such as SEM.

The dimension of the first pattern measured by the measuring device is W1. The dimension of the second pattern is W2. The dimension of the third pattern is W3. The dimension of the fourth pattern is W4. The dimension of the fifth pattern is W5. The dimension of the sixth pattern is W6.

Next, based on the first value Ja, the second value Jb, the first time Ta, the second time Tb, the target dimension WT, and the first to sixth pattern dimensions W1 to W6, the optimum integrated exposure dose JOPT, and A process for determining the optimum development time TOPT is executed. In the present embodiment, calculation is performed using the known first value Ja, second value Jb, first time Ta, second time Tb, target dimension WT, and first to sixth pattern dimensions W1 to W6. Thus, the optimum integrated exposure amount JOPT and the optimum development time TOPT are determined.

Hereinafter, an example of a method for determining the optimum integrated exposure amount JOPT and the optimum development time TOPT will be described.

FIG. 18 is a diagram in which a part of the contour (outer shape) of the pattern of the photosensitive film formed on the substrate P is modeled. Each line L1, L1 ′, L2, L2 ′, L3, L3 ′, L4, and L4 ′ shown in FIG. 18 (A) models a part of the contour of the pattern of the photosensitive film in contact with the substrate by a linear expression. Is. In FIG. 18A, the horizontal axis represents the half value of the dimension (line width) of the photosensitive film pattern, and the vertical axis represents the height of the photosensitive film pattern.

In FIG. 18A, lines L4 and L4 ′ are contours of the photosensitive film that have the same bottom width of the photosensitive film pattern even when the exposure conditions and the development conditions are different, as shown in FIG. 18B. Represents part. In the present embodiment, the optimum integrated exposure amount JOPT and the optimum development time TOPT that can obtain the line L4 and the line L4 'are obtained by calculation described below.

Line L1 represents the contour of the pattern of the photosensitive film when the exposure and development are performed in the ideal state where the integrated exposure amount is Ja and the development time is Ta. A line L1 'represents the contour of the pattern of the photosensitive film when the exposure and development are performed with Ja as the integrated exposure amount and Ta as the development time in the joint displacement state. That is, the line L1 represents the contour of the pattern of the photosensitive film formed in the first area AR1 shown in FIG. 16, and the line L1 ′ represents the contour of the pattern of the photosensitive film formed in the second area AR2 shown in FIG. Represents.

Suppose that the line L1 is represented by the following equation (1A), and the line L1 'is represented by the following equation (2A).

y = a1x + b1 (1A)
y = a1′x + b1 ′ (2A)

Also, the coordinates of the intersection of the line L1 and the line L1 'are (WP / 2, hP).

Line L2 represents the contour of the pattern of the photosensitive film when the exposure and development are performed in the ideal state where the integrated exposure amount is Jb and the development time is Ta. A line L2 'represents the outline of the pattern of the photosensitive film when the exposure and development are performed with the integrated exposure amount being Jb and the development time being Ta in the joint displacement state. That is, the line L2 represents the contour of the pattern of the photosensitive film formed in the third area AR3 shown in FIG. 16, and the line L2 ′ represents the contour of the pattern of the photosensitive film formed in the fourth area AR4 shown in FIG. Represents.

The line L2 is represented by the following expression (3A), and the line L2 'is represented by the following expression (4A).

y = a2x + b2 (3A)
y = a2′x + b2 ′ (4A)

A2, b2, a2 ', b2' are proportional to the integrated exposure amount. The expressions (3A) and (4A) can be transformed into the following expressions (3A) and (4A).

y = (a1x + b1) × (Jb / Ja) (3A)
y = (a1′x + b1 ′) × (Jb / Ja) (4A)

The coordinates of the intersection of the line L2 and the line L2 'are (WP / 2, hP × (Jb / Ja)).

Line L3 represents the contour of the pattern of the photosensitive film when the exposure and development are performed in the ideal state where the integrated exposure amount is Ja and the development time is Tb. A line L3 'represents the outline of the pattern of the photosensitive film when the exposure and development are performed with the integrated exposure amount Ja and the development time Tb in the joint shift state. That is, the line L3 represents the outline of the pattern of the photosensitive film formed in the fifth area AR5 shown in FIG. 17, and the line L3 ′ represents the outline of the pattern of the photosensitive film formed in the sixth area AR6 shown in FIG. Represents.

Suppose that the line L3 is represented by the following expression (5A), and the line L3 'is represented by the following expression (6A). Here, it is assumed that a1 and a1 'do not change even if the development time changes.

y = a1x + b3 (5A)
y = a1′x + b3 ′ (6A)

Suppose that the coordinates of the intersection of the line L3 and the line L3 'are (WQ / 2, hQ).

The line L4 is represented by the following formula (7A), and the line L4 'is represented by the following formula (8A).

y = aOPT + bOPT (7A)
y = aOPT ′ + bOPT ′ (8A)

Suppose that the coordinates of the intersection of the line L4 and the line L4 'are (WT / 2, h0).

The intersection of the lines L1, L1 ', L2, L2', L3, L3 'and y = h0 is the half value of the bottom width measured using the measuring device. Therefore, the following equation holds.

h0 = a1W1 / 2 + b1 (9A)
h0 = a1′W1 ′ / 2 + b1 ′ (10A)
h0 = a1 (Jb / Ja) W2 / 2 + b1 (Jb / Ja) (11A)
h0 = a1 ′ (Jb / Ja) W2 ′ / 2 + b1 ′ (Jb / Ja) (12A)
h0 = a1W3 / 2 + b3 (13A)
h0 = a1′W3 ′ / 2 + b3 ′ (14A)

The following expressions are derived from the expressions (9A), (10A), (13A), and (14A).

b1 = h0-a1W1 / 2
b1 ′ = h0−a1′W1 ′ / 2
b3 = h0-a1W3 / 2
b3 ′ = h0−a1′W3 ′ / 2

The following formula (15A) is derived from the formulas (9A) and (11A), the following formula (16A) is derived from the formulas (10A) and (12A), and the formulas (9A) and (15A) From the equation, the following equation (17A) is derived, from the equations (10A) and (16A), the following equation (18A) is derived, and from the equations (13A) and (15A), the following (19A) The following equation (20A) is derived from the equations (14A) and (16A).

a1 = h0 × {1- (Jb / Ja)} / {(Jb / Ja) × (W2 / 2-W1 / 2)} (15A)
a1 ′ = h0 × {1- (Jb / Ja)} / {(Jb / Ja) × (W2 ′ / 2−W1 ′ / 2)} (16A)
b1 = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 / 2-W1 / 2)} × W1 / 2] (17A)
b1 ′ = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 ′ / 2−W1 ′ / 2) × W1 ′ / 2} (18A)
b3 = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 / 2-W1 / 2)} × W3 / 2] (19A)
b3 ′ = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 ′ / 2−W1 ′ / 2) × W3 ′ / 2} (20A)

Since the line L1 and the line L1 'pass through the intersection (WP / 2, hP), the following expressions (21A) and (22A) are established.

hP = a1WP / 2 + b1 (21A)
hP = a1′WP / 2 + b1 ′ (22A)

Therefore, the following equations (23A) and (24A) are derived.

WP = 2 × (b1′−b1) / (a1−a1 ′) (23A)
hP = (a1b1′−a1′b1) / (a1−a1 ′) (24A)

Since the line L3 and the line L3 'pass through the intersection (WQ / 2, hQ), the following expressions (25A) and (26A) are established.

hQ = a1WQ / 2 + b3 (25A)
hQ = a1′WQ / 2 + b3 ′ (26A)

Therefore, the following equations (27A) and (28A) are derived.

WQ = 2 × (b3′−b3) / (a1−a1 ′) (27A)
hQ = (a1b3′−a1′b3) / (a1−a1 ′) (28A)

The coordinates of a point on the straight line passing through the point (WP / 2, hP) and the point (WQ / 2, hQ), where the half value of the dimension (line width) is equal to the half value WT / 2 of the target dimension WT, Assuming that WT / 2, hR), the point (WP / 2, hP), the point (WQ / 2, hQ), and the point (WT / 2, hR) are on the same straight line, so the following equation (29A) Holds.

(HQ-hP) / (WQ / 2-WP / 2) = (hR-hP) / (WT / 2-WP / 2) ... (29A)

If the equation (29A) is arranged for hR, the following equation (30A) is derived.

HR = hP + (WT-WP) × (hQ-hP) / (WQ-WP) ... (30A)

The following equation (31A) holds for the optimum integrated exposure amount JOPT.

JOPT / Ja = h0 / hR (31A)

The following equation (32A) is derived from equations (30A) and (31A).

JOPT = Ja * [h0 / {hP + (WT-WP) * (hQ-hP) / (WQ-WP)}] ... (32A)

Substituting (23A), (24A), (27A), and (28A) into (32A) yields the following (33A).

JOPT = Ja × h0 / [(a1b1′−a1′b1) / (a1−a1 ′) + {WT / 2− (b1′−b1) / (a1−a1 ′)} × (a1b3′−a1′b3 -A1b1'-a1'b1) / (b3'-b3-b1 '+ b1) (33A)

The following equation (34A) holds for the optimum development time TOPT.
(TOPT-Ta) / (Tb-Ta) = (WT / 2-WP / 2) / (WQ / 2-WP / 2) (34A)

When the equation (34A) is expanded for TOPT, the following equation (35A) is derived.

TOPT = Ta + (Tb−Ta) × (WT−WP) / (WQ−WP) (35A)

When the expressions (23A) and (27A) are substituted into the expression (35A), the following expression (36A) is derived.

TOPT = Ta + (Tb−Ta) × {(a1−a1 ′) × WT / 2− (b1′−b1)} / (b3′−b3−b1 ′ + b1) (36A)

When substituting the equations (15A) to (20A) into a1 to b3 'in the equation (33A) representing the optimum integrated exposure amount JOPT and the equation (36A) representing the optimum development time TOPT, h0 is deleted. Thus, the optimum integrated exposure amount JOPT and the optimum development time TOPT are derived.

Thus, the process (step SP1) for determining the optimum integrated exposure amount JOPT and the optimum development time TOPT using the test substrate Pt (Pt1, Pt2) is completed.

A pattern (device pattern) having a uniform and desired dimension is formed on the substrate P by subjecting the substrate P to the main exposure with the determined optimum integrated exposure amount JOPT and performing the main development with the determined optimum development time TOPT.

As described above, according to the present embodiment, a uniform pattern having a desired dimension can be formed on the substrate P. Therefore, generation | occurrence | production of a defective device can be suppressed.

In the above-described embodiment, the first to fourth patterns are formed on the first test substrate Pt1, and the fifth and sixth patterns are formed on the second test substrate Pt2. Each of the first to sixth patterns may be formed on different first to sixth test substrates. For example, the first and second patterns are formed on the first test substrate, and the third and fourth patterns are the first. The fifth and sixth patterns may be formed on the second test substrate, and the fifth and sixth patterns may be formed on the third test substrate.

In the above-described embodiment, the photosensitive film is a positive type. However, a negative type in which a portion not irradiated with the exposure light EL is removed by development may be used.

In the above-described embodiment, the first projection region PR1 of the first projection optical system PL1 on which the pattern image of the mask M is projected and the second projection optical system PL2 on which the pattern image of the mask M is projected. The substrate P is subjected to overlap exposure with a part of the second projection region PR2, and the substrate P is disposed in the first projection region PR1 and the second projection region PR2, so that the first projection region PR1 and the second projection region PR2 are exposed. The case where the exposure light EL is irradiated has been described as an example. Then, the optimum integrated exposure amount JOPT is applied to the dimension of the pattern formed on the substrate P by the exposure light EL applied to the non-overlapping portion A1 of the first projection region PR1 and the non-overlapping portion A2 of the second projection region PR2. The dimension of the pattern formed on the substrate P by the exposed exposure light EL and the dimension of the pattern formed on the substrate P by the exposure light EL irradiated to the overlapping portion B1 between the first projection region PR1 and the second projection region PR2. Are the integrated exposure amounts in the first projection region PR1 and the second projection region PR2, and the optimum development time TOPT is a development time in which the dimension of the pattern formed on the substrate P is the target value WT. did.

According to the pattern formation method of this embodiment, the mask M and the substrate P (that is, the mask stage 1 and the substrate stage 2) are moved synchronously in a predetermined scanning direction, and the pattern image of the mask M is transferred to the substrate P. In the scanning exposure to be projected onto the projection surface, relative vibration between the projection optical system and the substrate P (that is, relative vibration between the projection region and the substrate P), and relative vibration between the projection optical system and the mask M (that is, illumination region and mask M). The pattern can be made uniform even when overlapping exposure is caused by the relative vibration of at least one of the relative vibrations in the same manner as in the joint displacement state. Here, the relative vibration means that the relative position between the projection optical system and the substrate P or the mask M is a component different from the intended synchronous movement, and the surface of the substrate P (photosensitive surface) or the surface of the mask M (pattern surface). ) In the direction along).

[Second Embodiment]
Next, a second embodiment will be described. In the following description, the same or equivalent components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is simplified or omitted.

In the above-described first embodiment, when the substrate P is subjected to overlapping exposure, the dimension of the pattern formed on the substrate P by the exposure light EL irradiated to the non-overlapping portion and the exposure light EL irradiated to the overlapping portion. The case where the exposure conditions and development conditions that can substantially match the dimensions of the pattern formed on the substrate P has been described. In the second embodiment, the dimension of the pattern formed on the substrate P exposed in a state of being arranged at the first position with respect to the image plane of the projection optical system PL, and the image plane of the projection optical system PL. A case will be described in which the exposure condition and the development condition are determined so that the dimensions of the pattern formed on the substrate P exposed in a state of being arranged at the second position different from the first position can be made substantially coincident.

Note that the pattern forming method according to the first embodiment described above is applied to a multi-lens type exposure apparatus having a plurality of projection optical systems PL1 to PL7. The pattern forming method according to the second embodiment can be applied to a so-called single lens type exposure apparatus having one projection optical system PL, and can also be applied to a multi-lens type exposure apparatus. In the following description, it is assumed that the exposure apparatus EX is a single lens type exposure apparatus having one projection optical system PL, and that the projection optical system PL has one projection region PR.

For example, when exposure is performed while moving the substrate P in the X-axis direction with respect to the projection region PR of the projection optical system PL, the position of the surface (exposure surface) of the substrate P in the Z-axis direction may change. is there. In other words, during the exposure of the substrate P, there is a possibility that the position of the surface (exposure surface) of the substrate P shifts with respect to the image plane of the projection optical system PL. In the present embodiment, the image plane of the projection optical system PL is substantially parallel to the XY plane, and the direction perpendicular to the image plane of the projection optical system PL during the exposure of the substrate P (Z-axis direction). Alternatively, there is a possibility that the position of the surface of the substrate P is shifted in the direction of inclination (direction θX, θY). As a result, the dimension of the pattern formed on the substrate P may be nonuniform.

For example, when the surface of the substrate P is exposed with respect to the image plane of the projection optical system PL arranged in the first position in the Z-axis direction, the dimension of the pattern formed on the substrate P and the first position There is a possibility that the dimension of the pattern formed on the substrate P will be different when exposed in a state of being arranged at a different second position.

Therefore, in the present embodiment, even when the position of the surface of the substrate P with respect to the image plane of the projection optical system PL in the Z-axis direction fluctuates, the process includes an exposure condition and a development condition that can prevent the pattern from becoming non-uniform. A case where conditions are determined will be described. An exposure process and a development process for manufacturing a device on the substrate P are executed based on the determined process conditions.

As in the first embodiment described above, the exposure conditions include the integrated exposure amount of the exposure light EL that is irradiated onto the projection area where the substrate P is disposed. The development conditions include the development time of the substrate P irradiated with the exposure light EL (the time during which the developer and the photosensitive film of the substrate P are in contact), the type (physical properties) of the developer to be used, and the like.

That is, the predetermined exposure condition includes an integrated exposure amount at which the dimension of the pattern formed on the substrate P becomes uniform. In the present embodiment, the accumulated exposure amount is determined by the exposure light EL emitted from the projection optical system PL in a state where the surface of the substrate P is disposed at the first position with respect to the image plane of the projection optical system PL. Formed on the substrate P by the exposure light EL emitted from the projection optical system PL in a state where the surface of the substrate P is disposed at the second position with respect to the dimension of the pattern formed on the projection optical system PL. The integrated exposure amount in the projection region PR in which the dimension of the pattern to be substantially matched is included. The predetermined development conditions include a development time in which the dimension of the pattern formed on the substrate P is a target value.

Hereinafter, the optimum integrated exposure amount and the optimum development time that can make the pattern uniform on the substrate P according to the present embodiment will be described.

FIG. 19 shows exposure in a state where the surface of the substrate P is disposed at each of the first position, the second position, the third position, the fourth position, and the fifth position, which are different from each other with respect to the image plane of the projection optical system PL. The relationship between the pattern of the mask M and the integrated exposure amount on the surface of the substrate P in the case where it is done is shown. The pattern of the mask M is a line and space pattern, and a transmission part (space part) 21 that transmits the exposure light EL from the illumination system IS and a light shielding part (line part) that blocks the exposure light EL from the illumination system IS. ) 22. In the graph shown in FIG. 19, the horizontal axis indicates the position of the surface of the substrate P, and the vertical axis indicates the value of the integrated exposure amount in the projection region PR disposed on the surface of the substrate P.

In the graph shown in FIG. 19, the line LF1 indicates the substrate when the exposure light EL is irradiated to the projection region PR in a state where the surface of the substrate P is disposed at the first position with respect to the image plane of the projection optical system PL. An example of the distribution of accumulated exposure on the surface of P is shown. Similarly, the lines LF2 to LF5 are obtained when the projection region PR is irradiated with the exposure light EL in a state where the surface of the substrate P is disposed at the second to fifth positions with respect to the image plane of the projection optical system PL. An example of the distribution of the integrated exposure amount on the surface of the substrate P is shown.

In the following description, the state in which the surface of the substrate P is disposed at the first position with respect to the image plane of the projection optical system PL is appropriately referred to as a first focus state. Similarly, the state where the surface of the substrate P is disposed at the second to fifth positions with respect to the image plane of the projection optical system PL will be appropriately referred to as second to fifth focus states, respectively.

As an example, the first position is a position (best focus position) where the surface of the substrate P coincides with the image plane of the projection optical system PL. The second to fifth positions are positions (defocus positions) where the surface of the substrate P is displaced from the image plane of the projection optical system PL. In the following description, a state in which the surface of the substrate P coincides with the image plane of the projection optical system PL is referred to as a best focus state as appropriate, and a state in which the surface of the substrate P is displaced from the image plane of the projection optical system PL. This will be referred to as a defocused state as appropriate.

Therefore, in the example shown in FIG. 19, the first focus state is the best focus state, and the first position is the position of the surface of the substrate P in the best focus state. The second to fifth focus states are defocus states, and the second to fifth positions are the positions of the surface of the substrate P in the defocus state. In the present embodiment, as an example, the second position is a position shifted by 10 μm with respect to the image plane of the projection optical system PL, and the third position is shifted by 20 μm with respect to the image plane of the projection optical system PL. The fourth position is a position shifted by 30 μm with respect to the image plane of the projection optical system PL, and the fifth position is a position shifted by 40 μm with respect to the image plane of the projection optical system PL.

As shown in FIG. 19, the integrated exposure amount in the first focus state, the integrated exposure amount in the second focus state, the integrated exposure amount in the third focus state, the integrated exposure amount in the fourth focus state, and the fifth focus There is a value Jk that matches the integrated exposure amount in the state. That is, by setting the integrated exposure amount in the best focus state to the value Jh, even if the position of the surface of the substrate P changes with respect to the image plane of the projection optical system PL, the integrated exposure amount matches the value Jk.

Accordingly, as the photosensitive film used for the substrate P, when the integrated exposure amount of the exposure light EL is greater than or equal to the value Jk, it is removed by development, and when it is less than the value Jk, it remains on the substrate P even after development (the pattern is changed). By using a photosensitive film having characteristics (photosensitive characteristics and solubility), the dimensions of the pattern of the photosensitive film formed on the substrate P can be matched in each of the first to fifth focus states.

As described above, the value Jh of the integrated exposure amount in the best focus state is determined according to the photosensitive characteristic (solubility) of the substrate P (photosensitive film), and the projection region is set so that the integrated exposure amount in the best focus state becomes the value Jh. By irradiating PR with exposure light EL, a pattern (see FIG. 10) having the same dimension Wa is formed on the substrate P in each of the first to fifth focus states, as in the first embodiment.

That is, even in the defocused state, it is formed on the substrate P by the dimension of the pattern formed on the substrate P by the exposure light EL irradiated in the best focus state and the exposure light EL irradiated in the defocused state. The dimension of the pattern is the same. Therefore, it is possible to prevent the pattern formed on the substrate P from becoming non-uniform.

FIG. 20 shows distributions of the integrated exposure amounts in the best focus state and the defocus state when the value of the integrated exposure amount in the best focus state is changed. Line LODB indicates the best focus state when the integrated exposure value in the best focus state is Jh1, and line LODD indicates the defocus state, and the integrated exposure value in the best focus state is Jh1. The case is shown. Line LBDB indicates the best focus state, and the value of the integrated exposure amount in the best focus state is Jh2, which is different from Jh1, and line LBDD is the defocus state, and indicates the integrated exposure amount in the best focus state. The case where the value is Jh2 is shown. Line LUDB indicates the best focus state, and the value of the integrated exposure amount in the best focus state is Jh3 different from Jh1 and Jh2. Line LUDD is the defocus state, and the integrated exposure in the best focus state. The case where the value of the quantity is Jh3 is shown.

As shown in FIG. 20, even when the integrated exposure value in the best focus state changes to the values Jh1, Jh2, and Jh3, the integrated exposure amount in the best focus state and the integrated exposure amount in the defocus state match. Jk1, Jk2, and Jk3 exist. Thereby, according to the photosensitive characteristic of the substrate P (photosensitive film), for example, an optimum value is determined from the values Jh1, Jh2, and Jh3, thereby making the pattern formed on the substrate P after development uniform. be able to.

For example, when the photosensitive film of the substrate P has a photosensitive characteristic that is removed by development when the integrated exposure amount of the irradiated exposure light EL is equal to or greater than the value Jk1, the value Jh1 is the integrated exposure amount in the best focus state. It is determined. Similarly, when the photosensitive film of the substrate P has a photosensitive characteristic that is removed by development when the integrated exposure amount of the irradiated exposure light EL is equal to or greater than the value Jk2, the value Jh2 is used as the integrated exposure amount in the best focus state. Is determined. When the photosensitive film on the substrate P has a photosensitive characteristic that is removed by development when the integrated exposure amount of the irradiated exposure light EL is equal to or greater than the value Jk3, the value Jh3 is the integrated exposure amount in the best focus state. It is determined.

In the following description, the integrated exposure amount that can suppress the pattern non-uniformity on the substrate P is appropriately referred to as an optimal integrated exposure amount JOPT.

Also, as described with reference to FIG. 10, the pattern dimension Wa is different from the target dimension WT. That is, in the substrate P, the pattern dimension Wa is uniform, but the dimension Wa is different from the target dimension WT. Therefore, as in the first embodiment described above, in this embodiment as well, by adjusting the development time T, the dimension of the pattern on the substrate P (photosensitive film pattern) is set to the target dimension WT. For example, as described with reference to FIG. 12, in the development process, the contour (outer shape) of the photosensitive film changes isotropically. Therefore, by adjusting the developing time T, the pattern of the photosensitive film having the dimension Wa can be changed to the pattern of the photosensitive film having the dimension WT.

As described above, the optimum integrated exposure amount JOPT corresponding to the predetermined exposure condition and the optimum development time TOPT corresponding to the predetermined development condition have been described.

In the pattern forming method according to the present embodiment, as shown in the flowchart of FIG. 13, a predetermined exposure condition (optimum integrated exposure amount JOPT) and a predetermined development condition (optimal development time) that can prevent the pattern from becoming non-uniform. (TOPT) is determined (step SP1), the substrate P is exposed with the determined predetermined exposure condition (optimum integrated exposure amount JOPT), and the substrate is determined with the determined predetermined development condition (optimum development time TOPT). Developing P (step SP2).

In the test exposure, the test substrate Pt is exposed. As the test board Pt, the first test board Pt1 and the second test board Pt2 are used.

In the present embodiment, as shown in the flowchart of FIG. 21, in the test exposure, the surface of the first area AR1 of the first test substrate Pt1 is set to the first position (for example, the best focus position) with respect to the image plane of the projection optical system PL. And exposing the first area AR1 of the first test substrate Pt1 by the exposure light EL irradiated to the projection area PR so that the integrated exposure amount in the projection area PR of the projection optical system PL becomes the first value Ja. (Step SC1) and disposing the surface of the second area AR2 of the first test substrate Pt1 at a second position (for example, a defocus position) different from the first position with respect to the image plane of the projection optical system PL, The second area AR2 of the first test substrate Pt1 is exposed by the exposure light EL irradiated to the projection area PR so that the integrated exposure amount in the projection area PR of the projection optical system PL becomes the first value Ja. (Step SC2), the third area AR3 of the first test substrate Pt1 is arranged at the first position with respect to the image plane of the projection optical system PL, and the integrated exposure amount in the projection area PR of the projection optical system PL is Exposing the third area AR3 of the first test substrate Pt1 with the exposure light EL irradiated to the projection area PR of the projection optical system PL so that the second value Jb is different from the first value Ja (step SC3); The fourth area AR4 of the first test substrate Pt1 is arranged at the second position with respect to the image plane of the projection optical system PL so that the integrated exposure amount in the projection area PR of the projection optical system PL becomes the second value Jb. In addition, the fourth area AR4 of the first test substrate Pt1 is exposed by the exposure light EL irradiated to the projection area PR of the projection optical system PL (step SC4), and the second image area of the projection optical system PL is second. Test board Pt Exposure light irradiated to the projection region PR of the projection optical system PL so that the integrated exposure amount in the projection region PR of the projection optical system PL becomes the first value Ja. The fifth area AR5 of the second test substrate Pt2 is exposed by EL (step SC5), and the sixth area AR6 of the second test substrate Pt2 is disposed at the second position with respect to the image plane of the projection optical system PL. The sixth area AR6 of the second test substrate Pt2 is exposed by the exposure light EL irradiated to the projection area PR of the projection optical system PL so that the integrated exposure amount in the projection area PR of the projection optical system PL becomes the first value Ja. Exposing (step SC6).

In this embodiment, as shown in the flowchart of FIG. 15, the test development is performed by developing the first test substrate Pt1 on which the first to fourth areas AR1 to AR4 are exposed for the first time Ta, A pattern of a photosensitive film is formed on each of the first to fourth areas AR1 to AR4 of the substrate Pt1 (step SB1), and the second test substrate Pt2 on which the fifth and sixth areas AR5 and AR6 are exposed is formed on the second test substrate Pt2. And developing in a second time Tb different from 1 hour Ta to form a pattern of a photosensitive film in each of the fifth and sixth regions AR5 and AR6 of the second test substrate Pt2 (step SB2).

FIG. 22 is a schematic diagram illustrating an example of the first test board Pt1, and FIG. 23 is a schematic diagram illustrating an example of the second test board Pt2. In FIGS. 22 and 23, the shape of the projection region PR is a rectangle.

In the present embodiment, as shown in FIG. 22, in the best focus state, the exposure light EL from the mask M irradiated to the projection region PR is set so that the integrated exposure amount in the projection region PR becomes the first value Ja. The first area AR1 of the first test substrate Pt1 is exposed (Step SC1).

Further, in a predetermined defocus state, the second region of the first test substrate Pt1 is exposed by the exposure light EL from the mask M irradiated to the projection region PR so that the integrated exposure amount in the projection region PR becomes the first value Ja. AR2 is exposed (step SC2).

In the best focus state, the third area AR3 of the first test substrate Pt1 is exposed by the exposure light EL from the mask M irradiated to the projection area PR so that the integrated exposure amount in the projection area PR becomes the second value Jb. Exposure is performed (step SC3). The second value Jb is different from the first value Ja. In the present embodiment, the second value Jb is, for example, 1.2 times the first value Ja.

Further, in a predetermined defocus state (for example, the same defocus state as in step SC2), the exposure light from the mask M irradiated to the projection region PR so that the integrated exposure amount in the projection region PR becomes the second value Jb. The fourth area AR4 of the first test substrate Pt1 is exposed by EL (step SC4).

Further, as shown in FIG. 23, in the best focus state, the second test substrate is irradiated with the exposure light EL from the mask M irradiated on the projection region PR so that the integrated exposure amount in the projection region PR becomes the first value Ja. The fifth area AR5 of Pt2 is exposed (step SC5).

Further, in a predetermined defocus state (for example, the same defocus state as in step SC2), the exposure light from the mask M irradiated on the projection region PR so that the integrated exposure amount in the projection region PR becomes the first value Ja. The sixth area AR6 of the second test substrate Pt2 is exposed by EL (step SC6).

Further, development processing is performed on the second test substrate Pt2 (step SB2). The development time of the second test substrate Pt2 is the second time Tb. The first time Ta and the second time Tb are different. In the present embodiment, the second time Tb is, for example, 0.8 times the first time Ta.

The dimension of the first pattern measured by the measuring device is W1. The dimension of the second pattern is W1 '. The dimension of the third pattern is W2. The dimension of the fourth pattern is W2 '. The dimension of the fifth pattern is W3. The dimension of the sixth pattern is W3 '.

Hereinafter, an example of a method for determining the optimum integrated exposure amount JOPT and the optimum development time TOPT will be described. The determination method according to the present embodiment is substantially the same as the procedure described with reference to FIG. 18 in the first embodiment described above. Hereinafter, a description will be given with reference to FIG.

Line L1 represents the contour of the pattern of the photosensitive film in the best focus state when the exposure and development are performed with the integrated exposure amount Ja and the development time Ta. A line L1 'represents the outline of the pattern of the photosensitive film when the exposure and development are performed in the defocus state where the integrated exposure amount is Ja and the development time is Ta. That is, the line L1 represents the contour of the pattern of the photosensitive film formed in the first area AR1 shown in FIG. 22, and the line L1 ′ represents the contour of the pattern of the photosensitive film formed in the second area AR2 shown in FIG. Represents.

Suppose that the line L1 is represented by the following equation (1B), and the line L1 'is represented by the following equation (2B).

y = a1x + b1 (1B)
y = a1′x + b1 ′ (2B)

Line L2 represents the contour of the pattern of the photosensitive film when the exposure and development are performed in the best focus state where the integrated exposure amount is Jb and the development time is Ta. A line L2 'represents the contour of the pattern of the photosensitive film when the exposure and development are performed in the defocus state where the integrated exposure amount is Jb and the development time is Ta. That is, the line L2 represents the contour of the pattern of the photosensitive film formed in the third area AR3 shown in FIG. 22, and the line L2 ′ represents the contour of the pattern of the photosensitive film formed in the fourth area AR4 shown in FIG. Represents.

Suppose that the line L2 is represented by the following equation (3B), and the line L2 'is represented by the following equation (4B).

y = a2x + b2 (3B)
y = a2′x + b2 ′ (4B)

A2, b2, a2 ', b2' are proportional to the integrated exposure amount. Expressions (3B) and (4B) can be transformed into the following expressions (3B) and (4B).

y = (a1x + b1) × (Jb / Ja) (3B)
y = (a1′x + b1 ′) × (Jb / Ja) (4B)

Line L3 represents the contour of the pattern of the photosensitive film when the exposure and development are performed in the best focus state where the integrated exposure amount is Ja and the development time is Tb. A line L3 'represents the contour of the pattern of the photosensitive film when the exposure and development are performed in the defocus state where the integrated exposure amount is Ja and the development time is Tb. That is, the line L3 represents the outline of the pattern of the photosensitive film formed in the fifth area AR5 shown in FIG. 23, and the line L3 ′ represents the outline of the pattern of the photosensitive film formed in the sixth area AR6 shown in FIG. Represents.

The line L3 is represented by the following expression (5B), and the line L3 'is represented by the following expression (6B). Here, it is assumed that a1 and a1 'do not change even if the development time changes.

y = a1x + b3 (5B)
y = a1′x + b3 ′ (6B)

Suppose that the line L4 is represented by the following formula (7B), and the line L4 'is represented by the following formula (8B).

y = aOPT + bOPT (7B)
y = aOPT ′ + bOPT ′ (8B)

h0 = a1W1 / 2 + b1 (9B)
h0 = a1′W1 ′ / 2 + b1 ′ (10B)
h0 = a1 (Jb / Ja) W2 / 2 + b1 (Jb / Ja) (11B)
h0 = a1 ′ (Jb / Ja) W2 ′ / 2 + b1 ′ (Jb / Ja) (12B)
h0 = a1W3 / 2 + b3 (13B)
h0 = a1′W3 ′ / 2 + b3 ′ (14B)

The following equations are derived from the equations (9B), (10B), (13B), and (14B).

The following formula (15B) is derived from the formulas (9B) and (11B), and the following formula (16B) is derived from the formulas (10B) and (12B), and the formulas (9B) and (15B) are derived. From the equation, the following equation (17B) is derived, from the equations (10B) and (16B), the following equation (18B) is derived, and from the equations (13B) and (15B), the following (19B) The following equation (20B) is derived from the equations (14B) and (16B).

a1 = h0 × {1- (Jb / Ja)} / {(Jb / Ja) × (W2 / 2-W1 / 2)} (15B)
a1 ′ = h0 × {1- (Jb / Ja)} / {(Jb / Ja) × (W2 ′ / 2−W1 ′ / 2)} (16B)
b1 = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 / 2-W1 / 2)} × W1 / 2] (17B)
b1 ′ = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 ′ / 2−W1 ′ / 2) × W1 ′ / 2} (18B)
b3 = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 / 2-W1 / 2)} × W3 / 2] (19B)
b3 ′ = h0 × [1- {1- (Jb / Ja)} / {(Jb / Ja) × (W2 ′ / 2−W1 ′ / 2) × W3 ′ / 2} (20B)

Since the line L1 and the line L1 'pass through the intersection (WP / 2, hP), the following expressions (21B) and (22B) are established.

hP = a1WP / 2 + b1 (21B)
hP = a1′WP / 2 + b1 ′ (22B)

Therefore, the following equations (23B) and (24B) are derived.

WP = 2 × (b1′−b1) / (a1−a1 ′) (23B)
hP = (a1b1′−a1′b1) / (a1−a1 ′) (24B)

Since the line L3 and the line L3 'pass through the intersection (WQ / 2, hQ), the following expressions (25B) and (26B) are established.

hQ = a1WQ / 2 + b3 (25B)
hQ = a1′WQ / 2 + b3 ′ (26B)

Therefore, the following equations (27B) and (28B) are derived.

WQ = 2 × (b3′−b3) / (a1−a1 ′) (27B)
hQ = (a1b3′−a1′b3) / (a1−a1 ′) (28B)

The coordinates of a point on the straight line passing through the point (WP / 2, hP) and the point (WQ / 2, hQ), where the half value of the dimension (line width) is equal to the half value WT / 2 of the target dimension WT, Assuming that WT / 2, hR), the point (WP / 2, hP), the point (WQ / 2, hQ), and the point (WT / 2, hR) are on the same straight line, so the following equation (29B) Holds.

(HQ-hP) / (WQ / 2-WP / 2) = (hR-hP) / (WT / 2-WP / 2) ... (29B)

(29B) is rearranged for hR, the following (30B) is derived.

HR = hP + (WT-WP) × (hQ-hP) / (WQ-WP) ... (30B)

The following equation (31B) is established for the optimum integrated exposure amount JOPT.

JOPT / Ja = h0 / hR (31B)

The following equation (32B) is derived from equations (30B) and (31B).

JOPT = Ja × [h0 / {hP + (WT−WP) × (hQ−hP) / (WQ−WP)}]… (32B)

Substituting (23B), (24B), (27B), and (28B) into (32B) yields the following (33B).

JOPT = Ja × h0 / [(a1b1′−a1′b1) / (a1−a1 ′) + {WT / 2− (b1′−b1) / (a1−a1 ′)} × (a1b3′−a1′b3 -A1b1'-a1'b1) / (b3'-b3-b1 '+ b1) (33B)

The following equation (34B) holds for the optimum development time TOPT.
(TOPT-Ta) / (Tb-Ta) = (WT / 2-WP / 2) / (WQ / 2-WP / 2) (34B)

When the equation (34B) is expanded for TOPT, the following equation (35B) is derived.

TOPT = Ta + (Tb−Ta) × (WT−WP) / (WQ−WP) (35B)

Substituting (23B) and (27B) into (35B), the following (36B) is derived.

TOPT = Ta + (Tb−Ta) × {(a1−a1 ′) × WT / 2− (b1′−b1)} / (b3′−b3−b1 ′ + b1) (36B)

When substituting the formulas (15B) to (20B) into a1 to b3 'in the formula (33B) representing the optimum integrated exposure amount JOPT and the formula (36B) representing the optimum development time TOPT, h0 is deleted. Thus, the optimum integrated exposure amount JOPT and the optimum development time TOPT are derived.

In the present embodiment, the first to fourth patterns are formed on the first test substrate Pt1, and the fifth and sixth patterns are formed on the second test substrate Pt2. Each of the first to sixth patterns may be formed on different first to sixth test substrates. For example, the first and second patterns are formed on the first test substrate, and the third and fourth patterns are the second. The fifth and sixth patterns may be formed on the test substrate, and the fifth and sixth patterns may be formed on the third test substrate.

[Third Embodiment]
According to the pattern forming methods of the first and second embodiments described above, it is possible to calculate the optimum integrated exposure amount JOPT that can form a uniform pattern having a desired dimension on the substrate P. However, when the calculated optimum integrated exposure amount JOPT is very large, it is necessary to increase the intensity of light emitted from the mercury lamp 5, and the cost for forming the pattern increases. Further, depending on the sensitivity of the photosensitive film, it may be expected that a large integrated exposure amount is required before the test exposure described above. In such a case as well, since it is necessary to increase the intensity of light emitted from the mercury lamp 5, the cost for forming the pattern increases. Therefore, it is desirable that the nonuniformity of the pattern formed on the substrate P can be suppressed without increasing the integrated exposure amount. Therefore, the inventors of the present invention have conducted extensive research, and as a result, the value Jk and the L & S ratio of the mask pattern (the line width of the line part (line pattern) and the line width and ratio of the space part (space pattern)) It was found that there is a relationship as shown below.

FIG. 24A shows the defocus amount (0, 10, 20 [pitch]) when the line widths of the line pattern and the space pattern are 4.0 [μm] and 2.0 [μm], respectively (pitch 6 [μm]). It is a figure which shows the change of the integrated exposure amount accompanying the change of (micrometer)]. As shown in FIG. 24-1, when the line widths of the line pattern and the space pattern are 4.0 [μm] and 2.0 [μm], the value Jk1 is at the position of the relative intensity H1 = 0.18. The bottom width D1 is 2.80 [μm].

FIG. 24-2 illustrates the defocus amounts (0, 10, 20 [pitch]) when the line widths of the line pattern and the space pattern are 3.7 [μm] and 2.3 [μm], respectively (pitch 6 [μm]). It is a figure which shows the change of the integrated exposure amount accompanying the change of (micrometer)]. As shown in FIG. 24-2, when the line widths of the line pattern and the space pattern are 3.7 [μm] and 2.3 [μm] respectively, the value Jk2 is at the position of the relative intensity H2 = 0.226. The bottom width D2 is 2.82 [μm].

FIG. 24-3 illustrates the defocus amounts (0, 10, 20 [pitch]) when the line widths of the line pattern and the space pattern are 3.5 [μm] and 2.5 [μm], respectively (pitch 6 [μm]). It is a figure which shows the change of the integrated exposure amount accompanying the change of (micrometer)]. As shown in FIG. 24-3, when the line widths of the line pattern and the space pattern are 3.5 [μm] and 2.5 [μm], the value Jk3 is at the relative intensity H3 = 0.26. The bottom width D3 is 2.82 [μm].

FIG. 24-4 is accompanied by a change in defocus amount (0, 10, 20 [μm]) when the line widths of the line pattern and the space pattern are both 3.0 [μm] (pitch 6 [μm]). It is a figure which shows the change of integrated exposure amount. As shown in FIG. 24-4, when the line widths of the line pattern and the space pattern are both 3.0 [μm], the value Jk4 is at the position of the relative intensity H4 = 0.348, and the bottom width D4 is 2 .90 [μm].

FIG. 25 is a diagram in which changes in the accumulated exposure amount shown in FIGS. 24-1, 24-3, and 24-4 are superimposed and displayed. As is apparent from FIG. 25, when the L & S ratio of the mask pattern is changed with the pitch fixed, the bottom width D does not change greatly, but the value Jk changes greatly. Specifically, if the line width of the line pattern is reduced (the line width of the space pattern is increased) with the pitch fixed, the value Jk increases. Therefore, it can be seen that when the line width of the line pattern is reduced with the pitch fixed, the same effect as that obtained when the integrated exposure amount is increased can be obtained. On the other hand, as shown in FIG. 26, the value Jk increases as the light intensity increases. Accordingly, it is found that the values Jk1 to Jk4 shown in FIGS. 24-1 to 4 can be matched by changing the light intensity. FIG. 27 shows a state in which the integrated exposure values Jk1, Jk3, and Jk4 shown in FIGS. 24-1, 24-3, and 24-4 are matched by changing the light intensity. As shown in FIG. 27, it can be seen that the values Jk1, Jk3, and Jk4 match.

In summary, since the value Jk changes by changing the L & S ratio of the mask pattern without changing the pitch, the integrated exposure amount changes by changing the L & S ratio of the mask pattern without changing the pitch. It can be seen that the same effect as obtained can be obtained. Accordingly, when the calculated optimum integrated exposure amount JOPT is very large or when it is expected that a large integrated exposure amount is required before the test exposure is performed due to the sensitivity of the photosensitive film, the L & S of the mask pattern is performed. It is preferable to increase the value Jk by changing the ratio and suppress the nonuniformity of the pattern formed on the substrate without increasing the integrated exposure amount.

Hereinafter, a pattern forming method according to the third embodiment based on the above-described knowledge will be described with reference to a flowchart shown in FIG. FIG. 28 is a flowchart illustrating an example of a pattern forming method according to the third embodiment. In the present embodiment, first, an optimum integrated exposure amount JOPT for a pattern is calculated by performing test exposure and test development in the same manner as the pattern forming method according to the first and second embodiments (step SP11). Next, it is determined whether or not the calculated optimum integrated exposure amount JOPT is within a predetermined range (step SP12). As a result of the determination, when the optimum integrated exposure amount JOPT is within a predetermined range, the main exposure and the main development are performed in the same manner as the pattern forming method according to the first and second embodiments (step SP13). On the other hand, when the optimum integrated path light amount JOPT is not within the predetermined range, a mask pattern with a changed L & S ratio is prepared (SP14). Specifically, when the optimum integrated exposure amount JOPT is greater than or equal to a predetermined range, another mask pattern having the same pitch as the mask pattern used in step SP11 and having a smaller line width is used. prepare. Then, step SP11 is performed again using another prepared mask pattern, and the optimum exposure amount JOPT for the other mask pattern is calculated. If it is anticipated that a large integrated exposure amount will be required before the test exposure is performed due to the sensitivity of the photosensitive film, the process may be started from step SP14 described above.

As is clear from the above description, according to the pattern forming method of the third embodiment of the present invention, another mask pattern in which the L & S ratio is changed based on the magnitude of the optimum integrated exposure amount JOPT is prepared and prepared. Since the test exposure, test development, main exposure, and main development are performed using the different mask patterns, the non-uniformity of the pattern formed on the substrate can be suppressed without increasing the exposure amount.

The substrate P in the first and second embodiments described above is not only a glass substrate for display devices, but also a semiconductor wafer for manufacturing semiconductor devices, a ceramic wafer for thin film magnetic heads, or a mask used in an exposure apparatus. Alternatively, a reticle original (synthetic quartz, silicon wafer) or the like is applied.

As the exposure apparatus EX, a step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the substrate P with the exposure light EL through the pattern of the mask M by moving the mask M and the substrate P synchronously. In addition, the pattern of the mask M is collectively exposed while the mask M and the substrate P are stationary, and is applied to a step-and-repeat type projection exposure apparatus (stepper) that sequentially moves the substrate P stepwise. Can do.

Further, the present invention relates to a twin stage type exposure having a plurality of substrate stages as disclosed in US Pat. No. 6,341,007, US Pat. No. 6,208,407, US Pat. No. 6,262,796 and the like. It can also be applied to devices.

Further, the present invention relates to a substrate stage for holding a substrate as disclosed in US Pat. No. 6,897,963 and European Patent Application No. 1713113, and a reference mark without holding the substrate. The present invention can also be applied to an exposure apparatus that includes a formed reference member and / or a measurement stage on which various photoelectric sensors are mounted. An exposure apparatus including a plurality of substrate stages and measurement stages can be employed.

The type of the exposure apparatus EX is not limited to an exposure apparatus for manufacturing a liquid crystal display element or a display, but an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on a substrate P, a thin film magnetic head, an image sensor (CCD) In addition, the present invention can be widely applied to an exposure apparatus for manufacturing a micromachine, MEMS, DNA chip, reticle, mask, or the like.

In each of the above-described embodiments, the position information of each stage is measured using an interferometer system including a laser interferometer. However, the present invention is not limited to this. For example, a scale (diffraction grating) provided in each stage You may use the encoder system which detects this.

In the above-described embodiment, a light-transmitting mask in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. As disclosed in US Pat. No. 6,778,257, a variable shaped mask (also called an electronic mask, an active mask, or an image generator) that forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed. ) May be used. Further, a pattern forming apparatus including a self-luminous image display element may be provided instead of the variable molding mask including the non-luminous image display element.

The exposure apparatus EX of the above-described embodiment is manufactured by assembling various subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Is done. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. After the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room in which the temperature and cleanliness are controlled.

As shown in FIG. 29, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate which is a base material of the device. In step 203, the substrate processing includes exposing the substrate with the exposure light from the mask to project an image of the pattern onto the substrate and developing the exposed substrate (photosensitive film) according to the above-described embodiment. The substrate is manufactured through a substrate processing step 204 including an exposure process, a device assembly step (including processing processes such as a dicing process, a bonding process, and a package process) 205, an inspection step 206, and the like. Step 204 includes developing the photosensitive film to form an exposure pattern layer (development of the developed photosensitive film) corresponding to the mask pattern, and processing the substrate through the exposure pattern layer. It is. For example, processing the substrate includes etching the developed substrate.

It should be noted that the requirements of the above-described embodiments and modifications can be combined as appropriate. Some components may not be used. In addition, as long as it is permitted by law, the disclosure of all published publications and US patents related to the exposure apparatus and the like cited in the above-described embodiments and modifications are incorporated herein by reference.

In the above-described embodiment, the present invention has been described as being applied to an exposure apparatus. However, the present invention is not limited to an exposure apparatus, and for example, a plurality of processing regions provided on a substrate P are sequentially used with a microscope or the like. The present invention can also be applied to an inspection apparatus that observes and inspects.

DESCRIPTION OF SYMBOLS 1 Mask stage 2 Substrate stage 4 Control apparatus M Mask P Substrate Pt Test substrate PL1-PL7 Projection optical system PR1-PR7 Projection area

Claims

A pattern forming method for forming a pattern on a photosensitive substrate by irradiating a photosensitive substrate with exposure light from a projection optical system through a mask pattern having a line portion and a space portion,
Determining whether or not an integrated exposure amount in a projection area of a projection optical system necessary for forming the pattern on the substrate is within a predetermined range;
When the integrated exposure amount is not within a predetermined range, the mask pattern is different in that the pitch between the line portion and the space portion is the same, and the ratio between the line width of the line portion and the line width of the space portion is different. Changing to the mask pattern of
Determining exposure conditions and development conditions using the different mask pattern;
Exposing the substrate with exposure light applied to the projection region under the exposure conditions;
Developing the substrate under the development conditions;
A pattern forming method comprising:
In the mask pattern change, when the integrated exposure amount is not less than a predetermined range, the mask pattern has the same pitch between the line portion and the space portion, and the line width of the line portion is shortened. The pattern forming method according to claim 1, further comprising changing to another mask pattern.
Determining exposure conditions and development conditions using the other mask pattern,
The exposure surface of the first substrate is arranged at a first position with respect to the image plane of the projection optical system, and the projection area is irradiated so that the integrated exposure amount in the projection area of the projection optical system becomes a first value. Exposing the first substrate with the exposed exposure light;
The exposure area of the second substrate is arranged at a second position different from the first position with respect to the image plane, and the projection area is irradiated so that the integrated exposure amount in the projection area becomes the first value. Exposing the second substrate with the exposure light;
The exposure irradiated to the projection area such that the third substrate is disposed at the first position with respect to the image plane, and the integrated exposure amount in the projection area becomes a second value different from the first value. Exposing the third substrate with light;
The fourth substrate is arranged at the second position with respect to the image plane, and the fourth exposure light irradiated onto the projection area is set to the fourth value so that the integrated exposure amount in the projection area becomes the second value. Exposing the substrate;
A fifth substrate is arranged at the first position with respect to the image plane, and the fifth exposure light irradiated onto the projection area causes the fifth exposure light to irradiate the projection area so that the integrated exposure amount in the projection area becomes the first value. Exposing the substrate;
A sixth substrate is arranged at the second position with respect to the image plane, and the sixth exposure light is applied to the projection area so that the integrated exposure amount in the projection area becomes the first value. Exposing the substrate;
Developing the first substrate in a first time to form a first pattern on the first substrate;
Developing the second substrate in the first time to form a second pattern on the second substrate;
Developing the third substrate in the first time to form a third pattern on the third substrate;
Developing the fourth substrate in the first time to form a fourth pattern on the fourth substrate;
Developing the fifth substrate at a second time different from the first time to form a fifth pattern on the fifth substrate;
Developing the sixth substrate in the second time to form a sixth pattern on the sixth substrate;
Determining exposure conditions and development conditions based on the first to sixth patterns;
The pattern forming method according to claim 1, further comprising:
Measuring the dimensions of the first pattern, the second pattern, the third pattern, the fourth pattern, the fifth pattern, and the sixth pattern, and determining the exposure condition and the development condition is a measurement 4. The pattern forming method according to claim 3, wherein the pattern forming method is performed based on a measurement result of the measured dimension, the first value, the second value, the first time, the second time, and the dimension. .
The at least two of the first substrate, the second substrate, the third substrate, the fourth substrate, the fifth substrate, and the sixth substrate are the same substrate. Or the pattern formation method of 4.
The exposure condition is that the dimension of the pattern formed on the substrate disposed at the first position relative to the image plane and the dimension of the pattern formed on the substrate disposed at the second position are approximately 6. The pattern forming method according to claim 3, further comprising an exposure amount in the matching projection region.
7. The pattern forming method according to claim 3, wherein the developing condition includes a developing time in which a dimension of the pattern formed on the substrate is a target value.
Forming a pattern on a substrate using the pattern forming method according to any one of claims 1 to 7,
Processing the substrate on which the pattern is formed;
A device manufacturing method comprising: