Exposure apparatus, exposure method, and method for producing article

Abstract

To provide a master holder that is advantageous in conducting exposure.SOLUTION: A master holder that holds a master, the master holder including a holder section that holds at least a part of a lower surface of the master, and a sealing member that seals gas flowing between the master and the holder section.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an exposure apparatus, an exposure method, and a method for manufacturing an article. [Background technology]

[0002] Exposure apparatus are known as one type of lithography equipment used in the manufacturing process of semiconductor devices, flat panel displays (FPDs), etc. Exposure apparatuses perform an exposure process in which a substrate is exposed to light through an original, thereby transferring (forming) the circuit pattern formed on the original onto the substrate.

[0003] In recent years, the miniaturization of circuit patterns has created a demand for chucks that can maintain the flatness of originals with high precision. However, it is difficult to achieve this with a chuck that can hold originals of multiple sizes. For this reason, recent exposure apparatuses generally support only one type of original size. However, as disclosed in Patent Document 1, a technology is disclosed that provides an original attachment (original holder) that enables exposure even with different original sizes.

[0004] Furthermore, in recent exposure apparatuses, as originals become larger, they tend to bend under their own weight, which can reduce exposure accuracy. To address this issue, a known technique is to position a deflection correction unit above the original, forming an airtight space capable of controlling the pressure, and to correct the deflection of the original by controlling the pressure in the airtight space. Patent Document 2 discloses details regarding the deflection correction unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 162396 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-128646 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the original attachment described in Patent Document 1 is used, a space exists between the original and the original attachment. As a result, it is not possible to form an airtight space above the original in which pressure can be controlled, and when the deflection correction unit described in Patent Document 2 is applied, it may be difficult to correct the deflection of the original. This may result in a decrease in exposure accuracy.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an original holder that is advantageous for exposure. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, one aspect of the present invention is an original plate holder that holds an original plate, characterized in that it has a holder portion that holds at least a portion of the underside of the original plate, and a sealing member that seals off gas flowing between the original plate and the holder portion. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an original holder that is advantageous for exposure. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus. [Figure 2] FIG. 10 is a diagram showing an example in which an original is placed on an original stage. [Figure 3] FIG. 2 is a perspective view showing the configuration of an original holder. [Figure 4] FIG. 2 is a top view showing a state in which the original is mounted on the original holder. [Figure 5] FIG. 10 is a diagram showing a state in which the master holder on which the master is mounted is placed on the master stage. [Figure 6] FIG. 2 is a diagram showing an original holder and a deflection correction unit. [Figure 7] FIG. 2 is a diagram illustrating the configuration of an original holder. [Figure 8] FIG. 10 is a diagram for explaining an example in which a sealing member is provided at a different location. [Figure 9] 1 is a flowchart of a method for manufacturing an article. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same components, and redundant explanations will be omitted.

[0012] FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus 100. The exposure apparatus 100 includes an illumination optical system 1, a detection unit 2, an original stage 4 on which an original 3 is placed, a projection optical system 5, a substrate stage 7 on which a substrate 6 is placed, and a control unit 8. The exposure apparatus 100 also includes an original drive mechanism 9, a first measurement unit 10 that measures the position of the original stage 4, reflecting mirrors 10a and 12a, a substrate drive mechanism 11, and a second measurement unit 12 that measures the position of the substrate stage 7. The original 3 and the substrate 6 are positioned at approximately optically conjugate positions (the object plane and image plane of the projection optical system 5) via the projection optical system 5. The exposure apparatus 100 is a lithography apparatus used, for example, in a lithography process in the manufacturing process of FPDs and semiconductor devices. The exposure apparatus 100 is an apparatus that performs an exposure process on, for example, a glass or silicon substrate 6 having a resist (photosensitive agent) applied to its surface.

[0013] In this specification and drawings, the substrate holding surface of the substrate stage 7 is shown as an XYZ coordinate system in which the XY plane is the substrate scanning direction, the X direction is the direction parallel to the substrate holding surface and orthogonal to the Y direction, and the Z direction is the direction perpendicular to the XY plane. Furthermore, rotation around the Z direction is θ. Figure 1 shows exposure apparatus 100 on the XZ plane as viewed from the Y direction.

[0014] The illumination optical system 1 illuminates the original 3 with light emitted from a light source (not shown), such as an ultra-high pressure mercury lamp or an LED. For example, the illumination optical system 1 may have a wavelength adjustment filter, a lens group, a shutter, etc., and may shape the light from the light source into exposure light with a wavelength and shape suitable for exposing the substrate 6, and illuminate the original 3. The original stage 4 is configured to hold the original 3 and be movable in the X and Y directions, and is driven in the X and Y directions by an original driving mechanism 9 under the control of a control unit 8.

[0015] The position of the original stage 4 can be constantly or periodically measured (monitored) by the first measurement unit 10. The first measurement unit 10 can include, for example, a laser interferometer. In this case, the first measurement unit 10 irradiates a reflecting mirror 10a arranged on the original stage 4 with measurement light and measures the position of the original stage 4 based on the measurement light reflected by the reflecting mirror 10a. This allows the control unit 8 to control the position of the original 3 placed on the original stage 4 based on the position of the original stage 4 measured by the first measurement unit 10. Furthermore, the control unit 8 can control the speed of the original 3 placed on the original stage 4 based on the change over time in the position of the original stage 4 measured by the first measurement unit 10.

[0016] The projection optical system 5 has multiple optical elements such as mirrors and lenses. The projection optical system 5 projects an image of the circuit pattern formed on the original 3 onto the substrate 6 at a predetermined magnification by reflecting and refracting the exposure light that has passed through the original 3 using multiple optical elements. The substrate stage 7 holds the substrate 6, and is driven in each of the X, Y, Z, ωX, ωY, and ωZ directions by a substrate driving mechanism 11 under the control of a control unit 8.

[0017] The position of the substrate stage 7 can be constantly or periodically measured (monitored) by the second measurement unit 12. The second measurement unit 12 can include, for example, a laser interferometer. In this case, the second measurement unit 12 irradiates a reflecting mirror 12a configured on the substrate stage 7 with measurement light and measures the position of the substrate stage 7 based on the measurement light reflected by the reflecting mirror 12a. This allows the control unit 8 to control the position of the substrate 6 placed on the substrate stage 7 based on the position of the substrate stage 7 measured by the second measurement unit 12. Furthermore, the control unit 8 can control the speed of the substrate 6 placed on the substrate stage 7 based on the change over time in the position of the substrate stage 7 measured by the second measurement unit 12.

[0018] FIG. 2 shows an example in which a master 3a of a specified size is placed on a master stage 4. The master stage 4 may include a main body 4a and a master chuck 4b. The main body 4a is driven in the X and Y directions by a master drive mechanism 9, and the master chuck 4b is a mechanism that attracts and holds the master 3a using vacuum suction, electrostatic suction, or the like. Because the master 3a is configured so that only the vicinity of its side surface is held by the master chuck 4b, it may bend due to its own weight. The deflection correction unit 15 corrects this deflection. The deflection correction unit 15 is placed on the master 3a and is a space above the master. By creating a deflection control space S between the master 3a and the deflection correction unit 15 at a negative pressure relative to atmospheric pressure (the air pressure outside the deflection control space S), the amount of deflection of the master 3a due to its own weight can be corrected. The deflection correction unit 15 performs the above-described deflection correction during exposure, thereby reducing the deterioration of exposure accuracy caused by the deflection of the original 3 a. The deflection correction unit 15 has an airtight member that covers the upper side of the original (specifically, the top and side surfaces in the deflection control space S), and a pressure control unit (not shown) that controls the pressure in the deflection control space S.

[0019] In the exposure apparatus 100 of this embodiment, only originals of a predetermined size can be placed on the original stage 4. Since the size of the original may vary depending on the product being produced, this can be disadvantageous for users of the exposure apparatus 100 in terms of cost, etc. Therefore, by using an original holder that can be attached as an attachment to the original 3a, exposure can be performed even if the original size varies. Specifically, it becomes possible to use originals that are smaller than those that can be applied to the original stage 4.

[0020] However, when an original holder is used, there is a risk of a space being formed between the original and the original holder. Therefore, it is not possible to form an airtight space above the original in which pressure can be controlled. Therefore, when the above-described deflection correction unit is applied, it may be difficult to correct the deflection of the original. This may result in a decrease in exposure accuracy. In this embodiment, a description is given of an original holder 21 in which deflection can be corrected by a deflection correction unit.

[0021] FIG. 3 is a perspective view showing the configuration of the master holder 21 of this embodiment. The master holder 21 has a holder unit 20 that holds (supports) at least a portion of the underside of the master. The holder unit 20 holds the vicinity of the edge of the master. Specifically, the holder unit 20 may include a first member 20a that holds (supports) at least a portion of the underside of the master, and a second member 20b that is arranged at a different level from the first member and is suction-held by the master stage 4 (master chuck 4b). This different level arrangement ensures that the height of the master 3a does not change whether the master holder 21 is used or not, which can be advantageous when adjusting the height position during exposure. Note that the design does not need to be completely height-invariant as described above; it is sufficient that the holder unit 20 has a surface that is higher than the contact surface that holds at least a portion of the underside of the master 3a. This reduces the amount of correction required for the height position of the original 3 a compared to a configuration in which the holder 20 does not have a surface that is higher than the contact surface that holds at least a portion of the underside of the original 3 a. For convenience of explanation, the first member 20 a and the second member 20 b are described as separate members, but they can also be interpreted as an integrated member.

[0022] The first member 20a may be formed by arranging a plurality of members with gaps therebetween, as shown in Fig. 3. The gaps may be provided so that a transport device (not shown), which transports the master 3a while holding it, does not interfere with the master holder 21 when the master 3a is mounted on the master holder 21. Alternatively, the gaps may be provided from the perspective of reducing costs for the members. The number of members is not limited to eight as shown in Fig. 3, and may be any number.

[0023] FIG. 4 is a top view of the original holder 21 with an original 3b smaller than the specified size placed on it. FIG. 5 shows an example in which the original holder 21 with the original 3b mounted thereon is placed on the original stage 4. During exposure in the exposure apparatus 100, the original stage 4 undergoes accelerated motion, causing inertial forces to act on the original 3b and the holder unit 20, resulting in a large force. The holder unit 20 (second member 20b) is held by suction by the original chuck 4b and therefore does not shift position. However, since the original 3b is placed on the holder unit 20 (first member 20a), it may shift position depending on the magnitude of the acceleration. In other words, a mechanism for fixing the original 3b is required, separate from the original chuck 4b.

[0024] 6 is a diagram showing the master holder 21 placed on the master stage 4 and the deflection correction unit 15 arranged above the master 3b. As described above, the deflection correction unit 15 corrects deflection due to its own weight by creating a negative pressure in the deflection control space S, but there is a gap between the master 3b and the holder part 20 (first member 20a). Therefore, when attempting to create a negative pressure in the deflection control space S, gas leaks from the gap (air leak occurs), and the deflection correction unit 15 cannot create a negative pressure in the deflection control space S.

[0025] Therefore, the master holder 21 in this embodiment has a sealing member 34 that seals the gas flowing between the master 3b and the holder unit 20, as described below, thereby forming the deflection control space S. That is, the sealing member 34 seals the gas flowing from below the master 3b to above the master 3b through the gap between the master 3b and the holder unit 20. In this invention, sealing the gas does not necessarily mean reducing the amount of gas flowing above the master 3b to zero, but also means reducing the amount of gas flowing in to a level that allows a negative pressure to be created in the deflection control space S above the master. The sealing member 34 may be any member that can reduce the amount of gas flowing in compared to when the sealing member 34 is not provided. The sealing member 34 is preferably a member that reduces the amount of gas flowing in to 10% or less, more preferably 1% or less. FIG. 7 is a diagram showing the configuration of the master holder 21 in this embodiment. The original holder 21 has a holding member 30 that holds the upper surface of the original 3b and holds (fixes) the original 3b to the original holder 21.

[0026] The holding member 30 may include a metal plate portion 31, an original-side spacer 32, and a holder-side spacer 33. As shown in FIG. 7, the metal plate portion 31 is arranged to cover the space between the original 3b and the holder portion 20 (second member 20b). The metal plate portion 31 has a frame shape and is provided to cover the side of the original 3b so as not to block light irradiated onto the circuit pattern surface of the original 3b during exposure. The metal plate portion 31 is provided continuously around the edge of the original 3b, which strengthens the force with which the original 3b is fixed to the original holder 21 compared to when it is not continuous, which is advantageous for exposing the original 3b while scanning it. The metal plate portion 31 may be a leaf spring. The original-side spacer 32 is fixed to the inner edge of the metal plate portion 31 and is configured to come into contact with the original 3b. The holder-side spacer 33 is disposed on the outer edge of the sheet metal part 31 and is screwed together with the sheet metal part 31 to the holder part 20 (second member 20b). The original-side spacer 32 is designed to be thicker than the holder-side spacer 33. Therefore, the sheet metal part 31 bends when screwed together, and the resulting elastic force exerts a -Z direction force on the original 3b. By mounting the holding member 30 on the original holder 21 with the original 3b placed thereon, the original 3b is fixed, and exposure processing can be performed without misalignment even when the original stage 4 accelerates. Furthermore, since the holding member 30 does not require power or air piping, it can be mounted on the original holder 21 outside the exposure apparatus. Since the original 3b is fixed in place beforehand, the original holder 21 with the original 3b mounted thereon can be transported to the original stage 4 using a transport device. The same applies to removing the original from the original holder 21.

[0027] The sealing member 34 includes a first sealing member 34a that contacts the original 3b and a second sealing member 34b that contacts the holder part 20 (second member 20b). The sealing member 34 is provided in contact with the sheet metal part 31 and, like the sheet metal part 31, is provided so as to cover the side surface of the original 3b. The first sealing member 34a is preferably designed to be thicker than the original-side spacer 32. This defines a predetermined crushing margin for the first sealing member 34a, ensuring sufficient sealing force when the sheet metal part 31 applies a force in the -Z direction to the original 3b. The sealing member 34 is provided in the gap between the original 3b and the sheet metal part 31. The sealing member 34 is also provided so as to contact the edge of the original 3b and extend continuously around the entire circumference.

[0028] The second sealing member 34b is preferably designed to be thicker than the holder-side spacer 33. This provides a predetermined crushing margin for the second sealing member 34b, ensuring sufficient sealing force when the sheet metal part 31 and the holder-side spacer 33 are screwed to the holder part 20. The sealing member 34 may have any configuration, as long as it is configured in the air leakage flow path so that a deflection control space S is formed above the master 3b. For example, as shown in FIG. 8, the sealing member 34 (third sealing member 34c) may be provided on the side of the second member 20b in the holder part 20. More specifically, as shown in FIG. 8, the sealing member 34 (third sealing member 34c) may be provided between the first member 20a and the second member 20b.

[0029] The sealing member 34 may be made of a material containing rubber or resin in order to ensure sufficient sealing force as described above. The sealing member 34 is also called a seal material.

[0030] The above describes the inability to form a space due to gaps created by the divided arrangement of the first member 20a, but the cause of air leakage is not limited to this configuration. For example, even if the first member 20a is not divided and there are no gaps between the first members 20a (the first member 20a is configured as a single member), a small gap may still occur between the first member 20a and the original plate 3b. In this embodiment, the above configuration allows the formation of the deflection control space S even in such a configuration.

[0031] As described above, the holding member 30 is provided to fix the original 3b to the original holder 21. Furthermore, in this embodiment, the sealing member 34 is provided on the original holder 21, which is advantageous in correcting deflection of the original.

[0032] <Embodiments of manufacturing methods of articles> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing articles such as flat panel displays (FPDs), semiconductor devices, sensors, and optical elements. FIG. 9 is a flowchart of the method for manufacturing an article according to this embodiment. The method for manufacturing an article according to this embodiment includes a step of forming a latent image pattern on a photosensitive material coated on a substrate by exposure using the exposure apparatus 100 described above to obtain an exposed substrate (exposure step, step S11). The method also includes a step of developing the substrate exposed in this step to obtain a developed substrate (development step, step S12). Furthermore, the manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.) (processing step, step S13). The method for manufacturing an article according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0033] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0034] The disclosure of the present specification includes at least the following master holder, exposure apparatus, and article manufacturing method.

[0035] (Item 1) A master holder for holding a master, a holder portion that holds at least a portion of the lower surface of the master; a sealing member that seals off gas flowing between the master and the holder portion.

[0036] (Item 2) The original plate holder described in item 1 is characterized in that the sealing member reduces the amount of gas flowing from below the original plate to above the original plate through the gap between the original plate and the holder portion compared to when the sealing member is not provided.

[0037] (Item 3) 3. The master holder according to item 2, wherein the sealing member reduces the amount of the gas to 10% or less.

[0038] (Item 4) 4. The master holder according to any one of items 1 to 3, wherein the holder portion holds the vicinity of the edge of the master.

[0039] (Item 5) 5. The master holder according to any one of items 1 to 4, further comprising a holding member for holding the upper surface of the master.

[0040] (Item 6) 6. The master holder according to item 5, wherein the sealing member is provided on the holding member.

[0041] (Item 7) 7. The master holder according to item 5 or 6, wherein the sealing member is provided in a gap between the master and the holding member.

[0042] (Item 8) 8. The master holder according to any one of items 5 to 7, wherein the sealing member is provided in contact with the edge of the master and extends continuously around the entire circumference.

[0043] (Item 9) 9. The master holder according to any one of items 1 to 8, wherein the holder portion has a surface that is higher than a contact surface that holds at least a part of the lower surface of the master.

[0044] (Item 10) 7. The master holder according to item 6, wherein the sealing member is provided in a gap between the master and the holder part.

[0045] (Item 11) 11. The original holder according to any one of items 1 to 10, wherein the original holder is used in an exposure apparatus that exposes an image of a pattern of an original onto a substrate.

[0046] (Item 12) Item 12. The original holder according to item 11, wherein the original holder forms an airtight space between the original and a deflection correction unit that corrects deflection of the original.

[0047] (Item 13) The master holder according to any one of items 1 to 12, an original stage on which the original holder is placed; a deflection correction unit that corrects deflection of the original held by the original holder; and An exposure apparatus, wherein the deflection correction unit controls the pressure in the space above the original.

[0048] (Item 14) an exposure step of exposing a substrate using the exposure apparatus according to item 13 to obtain an exposed substrate; a developing step of developing the exposed substrate to obtain a developed substrate, A method for manufacturing an article, comprising manufacturing an article from the developed substrate. [Explanation of symbols]

[0049] 3, 3a, 3b original version 20 Holder part 21 Master holder 34 Sealing member

Claims

1. A master holder for holding a master, a holder portion that holds at least a portion of the lower surface of the master; a sealing member that seals off gas flowing between the master and the holder portion.

2. A master holder as described in claim 1, characterized in that the sealing member reduces the amount of gas flowing from below the master to above the master through the gap between the master and the holder portion compared to when the sealing member is not provided.

3. 3. The master holder according to claim 2, wherein the sealing member reduces the amount of the gas to 10% or less.

4. 2. The master holder according to claim 1, wherein the holder portion holds the vicinity of an edge of the master.

5. 2. The master holder according to claim 1, further comprising a holding member for holding the upper surface of the master.

6. 6. The master holder according to claim 5, wherein the sealing member is provided on the holding member.

7. 6. The original holder according to claim 5, wherein the sealing member is provided in a gap between the original and the holding member.

8. 6. The master holder according to claim 5, wherein the sealing member is provided so as to contact the edge of the master and to extend continuously around the entire circumference.

9. 2. The master holder according to claim 1, wherein the holder portion has a surface that is higher than a contact surface that holds at least a part of the lower surface of the master.

10. 7. The master holder according to claim 6, wherein the sealing member is provided in a gap between the master and the holder portion.

11. 2. The original holder according to claim 1, wherein the original holder is used in an exposure apparatus that exposes an image of a pattern of an original onto a substrate.

12. 12. The original holder according to claim 11, wherein the original holder forms an airtight space between the original and a deflection correction unit that corrects deflection of the original.

13. a master holder according to any one of claims 1 to 12; an original stage on which the original holder is placed; a deflection correction unit that corrects deflection of the original held by the original holder; and An exposure apparatus, wherein the deflection correction unit controls the pressure in the space above the original.

14. an exposure step of exposing a substrate using the exposure apparatus according to claim 13 to obtain an exposed substrate; a developing step of developing the exposed substrate to obtain a developed substrate, A method for manufacturing an article, comprising manufacturing an article from the developed substrate.

Images