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JP-7856411-B2 - Substrate holding plate, device manufacturing method, and exposure apparatus

JP7856411B2JP 7856411 B2JP7856411 B2JP 7856411B2JP-7856411-B2

Inventors

  • 宮内 裕樹

Assignees

  • キヤノン株式会社

Dates

Publication Date
20260511
Application Date
20211129

Claims (20)

  1. A substrate holder having a plurality of pin portions for supporting the substrate and a wall portion arranged around the plurality of pin portions, The wall portion has four corners and four sides connecting the corners, and the height of the corners is smaller than that of the sides. The density of the wall portion in the first region, which includes the first pin portion among the plurality of pin portions and the first wall portion among the wall portions , is smaller than the density of the wall portion in the second region, which includes the second pin portion among the plurality of pin portions and the second wall portion among the wall portions, and which has a shape congruent to the first region. In the first region, the first wall portion is formed lower than the first pin portion, and the portion from the first wall portion to the first pin portion is formed lower than the first wall portion. In the second region, the second wall portion is formed lower than the second pin portion, and the portion from the second wall portion to the second pin portion is formed lower than the second wall portion. A substrate holder characterized in that the height difference between the second wall portion and the second pin portion in the second region is greater than the height difference between the first wall portion and the first pin portion in the first region.
  2. The first region and the second region are square in shape, with sides of 50 mm or more and 80 mm or less. The substrate holding plate according to claim 1, characterized in that the density is 4.0% or more and 20.0% or less.
  3. The substrate holding plate according to claim 1 or 2, characterized in that the wall portion has a quadrilateral shape.
  4. The substrate holding plate has four substrate holding sections, each having the aforementioned wall section . The substrate holding plate according to any one of claims 1 to 3, characterized in that the substrate holding portions of the four substrate holding portions that are adjacent to each other are separated from each other by grooves .
  5. The wall portion has a quadrilateral shape with side length L, The substrate holding plate according to any one of claims 1 to 4, characterized in that the corner portion is a wall portion located within L/3 from the vertex of the wall portion, and the side portion is a wall portion other than the corner portion.
  6. The substrate holding plate according to any one of claims 1 to 5, characterized in that the height difference between the corner and the edge is 0.10 μm or more and 1.2 μm or less.
  7. The aforementioned wall portion is inclined, as described in any one of claims 1 to 6.
  8. The substrate holder plate has a first portion and a second portion in which the corners are more densely packed than in the first portion. The substrate holding plate according to any one of claims 1 to 7, characterized in that the height of the wall portion of the second portion is smaller than that of the first portion.
  9. The substrate holder according to any one of claims 1 to 8, characterized in that it has a suction hole for drawing air from the lower part of the substrate holder.
  10. The substrate holding plate according to any one of claims 1 to 9, characterized in that the height difference between the second wall portion and the second pin portion is 0.30 μm or more and 1.5 μm or less.
  11. The substrate holder according to any one of claims 1 to 10, characterized in that the height difference between the first pin portion and the second pin portion is smaller than the height difference between the first wall portion and the second wall portion.
  12. The substrate holder according to any one of claims 1 to 11, characterized in that the distance from the second wall portion to the second pin portion in the second region is 1.0 mm or more and 3.0 mm or less.
  13. The substrate holder according to any one of claims 1 to 12, characterized in that the height of the first pin portion and the second pin portion is 0.10 mm or more and 1.6 mm or less, and the distance between two adjacent pin portions among the plurality of pin portions is 1.0 mm or more and 20 mm or less.
  14. The substrate holding plate according to any one of claims 1 to 13, characterized in that the height of the first wall and the second wall is 0.10 mm or more and 1.5 mm or less, and the width of the first wall and the second wall is 0.50 mm or more and 2.0 mm or less.
  15. The substrate holder according to any one of claims 1 to 14, characterized in that the first pin portion and the second pin portion are cylindrical or truncated cone-shaped.
  16. The substrate holder according to any one of claims 1 to 15, characterized in that the substrate holder has a base portion with a substrate holding surface, and the plurality of pin portions and the wall portion are provided on the side of the base portion that faces the substrate holding surface.
  17. The substrate holder according to claim 16, characterized in that the base, the wall, and the plurality of pins are made of alumina.
  18. The substrate holder according to claim 16 or 17, characterized in that at least one of the surfaces of the base on the substrate holding surface, the uppermost surface of the plurality of pin portions, or the side surfaces of the plurality of pin portions is a rough surface.
  19. The substrate holding plate according to claim 18, characterized in that the rough surface has an arithmetic mean roughness Ra of 0.40 μm or more and 4.0 μm or less.
  20. A method for manufacturing a device, characterized by placing a substrate on a substrate holding plate according to any one of claims 1 to 19, and exposing the substrate to light.

Description

This invention relates to a substrate holding plate. Exposure equipment performs exposure processing on substrates made of glass, silicon, SiC, etc. When performing exposure processing on a substrate, it is desirable that no focus shift occurs during exposure, and this focus shift often depends on the flatness of the substrate holder. Therefore, a technique is known for correcting the flatness of the substrate by following the tip of the peripheral wall surrounding the outer circumference of the pins and chuck. For example, Patent Document 1 proposes an object holding device comprising a peripheral wall surrounding the outer circumference of a chuck and pins that contact a substrate, in which the height of the pins is designed to be the same as the height of the peripheral wall. Japanese Patent Publication No. 2021-81740 This is a perspective view of the circuit board holder.This is a perspective view showing the circuit board holders lined up.This is a magnified view of the circuit board holder.(a) is an enlarged view of the outer periphery 11 of the substrate holder shown in Figure 2, and (b) is a cross-sectional view of the portion indicated by line 7 in (a).(a) is an enlarged view of the corner portion 12 of the substrate holder plate shown in Figure 2, and (b) is a cross-sectional view of the portion indicated by line 8 in (a).(a) is an enlarged view of the central part 13 of the substrate holder shown in Figure 2, and (b) is a cross-sectional view of the portion indicated by line 9 in (a).This is a top view of the substrate holder according to the second embodiment.This is a perspective view of the substrate holding plate according to the third embodiment.This is a schematic diagram of the exposure apparatus according to this embodiment.Figure 2 is a top view of the substrate holder plate shown in Figure 2.A graph showing the relationship between the height difference between the wall and the pin section and the density of the wall section.A graph showing the results of Example 1.A graph showing the results of Comparative Example 1. The following describes embodiments for carrying out the present invention with reference to the drawings. However, the embodiments described below are only one embodiment of the invention and are not limited thereto. Common components will be described with reference to multiple drawings, and components with common reference numerals will be omitted from description as appropriate. Different items with the same name can be distinguished by adding "item number ○," such as "item number 1," "item number 2," etc. Figure 1 shows a perspective view of the substrate holder 1 according to this embodiment. The substrate holder 1 in this embodiment has a base portion 2, and on the base portion 2, a wall portion 3 and a plurality of pin portions 4. The wall portion 3 and pin portions 4 support the substrate 10. The wall portion 3 is arranged around the pin portions 4 so as to surround them, but gaps are acceptable as long as the substrate 10 can be held in place. By supporting the substrate 10 with the wall portion 3 and pin portions 4, the contact area between the substrate holder 1 and the substrate 10 is reduced, and damage to the substrate 10 can be suppressed compared to a case where the pin portions 4 are not provided. One of the two main surfaces (front and back) of the substrate holder plate 1 (referred to as the front for convenience) is the substrate holder surface. The base portion 2 has a wall portion 3 and a pin portion 4 on the side facing the substrate holder surface. At least the uppermost surface of the wall portion 3 and the uppermost and side surfaces of the pin portion 4 constitute the substrate holder surface. In this embodiment, the base portion 2, the wall portion 3, and the pin portion 4 are made of the same material, and the material constituting them is black alumina. However, it is not limited to black alumina; alumina, ceramics, zirconia, glass, plastic, metal, etc., may also be used. Furthermore, the substrate holder 1 has a suction hole 5 that draws air from the bottom, creating a low-pressure environment in the space separated by the wall 3. Vacuum suction of the substrate 10 is performed through the suction hole 5. If there are areas with high density in the wall portion 3, the contact area between the substrate 10 and the wall portion 3 increases in those areas. When the substrate 10 is held by suction, the substrate 10 will bend in areas other than the pin portion 4 and the wall portion 3, causing the substrate 10 to warp upwards in the pin portion 4 and the wall portion 3. This is thought to worsen the flatness of the substrate 10. Furthermore, when the contact area between the substrate 10 and the wall portion 3 is large, the amount by which the substrate 10 is warped by the wall portion 3 also increases. Because the contact area between the substrate 10 and the wall portion 3 varies depending on the density of the wall portion 3, the amount of wa