Electrostatic chuck, substrate holding device, and method for manufacturing electrostatic chuck

Abstract

An electrostatic chuck, a substrate fixing device, and a method for manufacturing the electrostatic chuck are disclosed. The electrostatic chuck (30) comprises: an insulating substrate (40) having a mounting surface (40A) for placing an object to be adsorbed and an opposite surface (40B) disposed on the opposite side of the mounting surface; and an air hole (60) that penetrates the insulating substrate in the thickness direction. The air hole comprises: a hole portion (61) extending from the opposite surface toward the mounting surface; an enlarged space (62) communicating with the hole portion (61) and expanding the space of the air hole in the planar direction; and a hole portion (63) communicating with the enlarged space and extending from the enlarged space toward the mounting surface. The hole portion (61) is configured not to overlap with the hole portion (63) when viewed from above. The planar dimension of the enlarged space is larger than the combined planar dimension of the hole portion (61) and the planar dimension of the hole portion (63). The dimension of the enlarged space along the thickness direction is smaller than the dimension of the hole portion (61) along the planar direction.

Description

Technical Field

[0001] This invention relates to an electrostatic chuck, a substrate fixing device, and a method for manufacturing an electrostatic chuck. Background Technology

[0002] Currently, film deposition apparatuses and plasma etching apparatuses used in the manufacture of semiconductor devices have stages for holding wafers in a vacuum processing chamber with high precision. As such stages, for example, a substrate fixing device has been proposed that uses an electrostatic chuck mounted on a base plate to hold the wafer.

[0003] As an example of a substrate fixing device, a configuration in which a gas supply section for cooling the wafer can be provided can be cited (see, for example, Patent Document 1). The gas supply section supplies gas to the surface of the electrostatic chuck via a gas flow path provided on the base plate and an air hole provided on the electrostatic chuck. The gas flow path is formed to extend linearly along the thickness direction of the base plate. The air hole is formed to extend linearly along the thickness direction of the electrostatic chuck.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-218352

[0005] However, regarding the aforementioned substrate fixing device, it is desirable to suppress abnormal discharge within the gas supply section. Summary of the Invention

[0006] According to one aspect of the present invention, an insulating substrate has: an insulating substrate having a mounting surface for placing an adsorbed object and an opposite surface disposed on the opposite side of the mounting surface; and a pore penetrating the insulating substrate in the thickness direction, the pore having: a first pore portion extending from the opposite surface toward the mounting surface; a first enlarged space communicating with the first pore portion and extending the space of the pore in a plane direction orthogonal to the thickness direction; and a second pore portion communicating with the first enlarged space and extending from the first enlarged space toward the mounting surface, the first pore portion being configured not to overlap with the second pore portion when viewed from above, the planar dimension of the first enlarged space being larger than the combined planar dimension of the first pore portion and the second pore portion, and the dimension of the first enlarged space along the thickness direction being smaller than the dimension of the first pore portion along the planar direction.

[0007] The effects of the invention

[0008] According to one aspect of the present invention, it has the effect of suppressing the generation of abnormal discharges. Attached Figure Description

[0009] Figure 1 This is a schematic cross-sectional view showing one embodiment of the substrate fixing device. Figure 2(1-1 line cross-section).

[0010] Figure 2 This is a schematic top view of a substrate fixing device according to one embodiment.

[0011] Figure 3 This is an exploded perspective view showing one embodiment of an electrostatic chuck.

[0012] Figure 4 This is a schematic top view of the insulating layers of an electrostatic chuck according to one embodiment.

[0013] Figure 5 This is a schematic cross-sectional view showing a method for manufacturing an electrostatic chuck according to one embodiment.

[0014] Figure 6 This is a schematic cross-sectional view showing a method for manufacturing an electrostatic chuck according to one embodiment.

[0015] Figure 7 This is a schematic cross-sectional view showing a method for manufacturing an electrostatic chuck according to one embodiment.

[0016] Figure 8 This is a schematic cross-sectional view showing a method for manufacturing an electrostatic chuck according to one embodiment.

[0017] Figure 9 This is a schematic cross-sectional view showing a method for manufacturing an electrostatic chuck according to one embodiment.

[0018] Figure 10 This is a schematic cross-sectional view showing a method for manufacturing an electrostatic chuck according to one embodiment.

[0019] Figure 11 This is an exploded perspective view showing a modified electrostatic chuck. Detailed Implementation

[0020] Hereinafter, one embodiment will be described with reference to the accompanying drawings.

[0021] Furthermore, for the accompanying drawings, feature parts are sometimes enlarged for ease of understanding, and the dimensional ratios of various structural elements may differ between drawings. Additionally, in sectional views, to facilitate understanding of the cross-sectional structure of each component, some section lines are represented by a pear-skin texture, while others are omitted. Moreover, in this specification, "top view" refers to... Figure 1 When observing an object from the vertical direction (the up and down direction in the diagram), "planar shape" refers to the shape observed from the vertical direction. Figure 1The shape of the object is observed in a vertical direction. In this specification, "vertical direction" and "left-right direction" refer to directions where the orientation of the reference numerals indicating each component in the accompanying drawings is set to the positive position. Furthermore, unless otherwise stated in other paragraphs, the numerical range of "X1 to X2" defined by the upper limit value X1 and the lower limit value X2 in the description of this invention refers to a range greater than or equal to X1 and less than or equal to X2.

[0022] (Overall structure of substrate fixing device 10)

[0023] like Figure 1 As shown, the substrate holding device 10 includes: a base plate 20; an electrostatic chuck 30 disposed on the base plate 20; and a gas supply unit 50. The electrostatic chuck 30 is bonded to the upper surface of the base plate 20, for example, by an adhesive such as silicone resin. Alternatively, the electrostatic chuck 30 can be fixed to the base plate 20 using screws. An object to be adsorbed (not shown) is placed on the upper surface of the electrostatic chuck 30. For example, a wafer can be held up as the object to be adsorbed. The diameter of the wafer can be, for example, approximately 8 inches, 12 inches, or 18 inches. The substrate holding device 10 adsorbs and holds the object to be adsorbed placed on the electrostatic chuck 30.

[0024] (Structure of base plate 20)

[0025] The base plate 20 is a substrate (base) for mounting the electrostatic chuck 30. The base plate 20 has rigidity to support the electrostatic chuck 30. Materials for the base plate 20 can include, for example, metallic materials such as aluminum, superhard alloys, or composite materials of these metallic materials and ceramic materials. In this embodiment, aluminum or an aluminum alloy is used from the viewpoints of easy availability, easy processing, and good thermal conductivity, and the surface of the aluminum alloy is anodized.

[0026] The shape and size of the base plate 20 can be arbitrary. For example, the base plate 20 may be formed into a circular plate shape to match the shape of the object to be adsorbed on the electrostatic chuck 30. The diameter of the base plate 20 can be, for example, approximately 150 mm to 500 mm. The thickness of the base plate 20 can be, for example, approximately 10 mm to 50 mm. Here, in this specification, "circular plate shape" refers to a planar shape that is circular and has a specified thickness. Furthermore, regarding "circular plate shape," the thickness relative to the diameter is arbitrary. Additionally, "circular plate shape" also includes shapes with locally formed concave or convex portions.

[0027] (Structure of electrostatic chuck 30)

[0028] The electrostatic chuck 30 includes: an insulating substrate 40 having a mounting surface 40A for placing an object to be adsorbed and an opposite surface 40B disposed on the opposite side of the mounting surface 40A; and an electrode (not shown) embedded in the insulating substrate 40. The electrostatic chuck 30 is a holding body for adsorbing and holding a wafer, which is an object to be adsorbed. Furthermore, the electrode (not shown) is, for example, an electrostatic electrode for adsorbing an object placed on the mounting surface 40A of the insulating substrate 40. The electrode, for example, utilizes the electrostatic force generated by a voltage applied from an adsorption power source disposed outside the substrate holding device 10 to adsorb and hold the object to be adsorbed on the mounting surface 40A. The electrostatic chuck 30 is, for example, a Johnson-Rahbek type electrostatic chuck. Alternatively, the electrostatic chuck 30 may also be a Coulomb force type electrostatic chuck.

[0029] (Structure of insulating substrate 40)

[0030] The shape and size of the insulating substrate 40 can be arbitrary. For example, the insulating substrate 40 can be formed as a circular plate. The diameter of the insulating substrate 40 can be equal to or smaller than the diameter of the base plate 20. For example, the diameter of the insulating substrate 40 can be approximately 150 mm to 500 mm. The thickness of the insulating substrate 40 can be approximately 1 mm to 10 mm.

[0031] As the material for the insulating substrate 40, materials with insulating properties can be used. For example, ceramic materials such as alumina (Al2O3), aluminum nitride (AlN), and silicon nitride, as well as organic materials such as silicone resin and polyimide resin, can be used as the material for the insulating substrate 40. In this embodiment, from the viewpoints of easy availability, easy processing, and high resistance to plasma, ceramic materials such as alumina and aluminum nitride are used as the material for the insulating substrate 40. That is, the insulating substrate 40 of this embodiment is a ceramic substrate made of ceramic materials.

[0032] The insulating substrate 40 has, for example, a structure having multiple layers (four layers in this case) of insulating layers 41, 42, 43, and 44 stacked together. Each insulating layer 41, 42, 43, and 44 is, for example, a sintered body formed by sintering a green sheet composed of a mixture of alumina and organic materials. In the figures, solid lines indicate the interfaces between insulating layers 41 and 42, between insulating layers 42 and 43, and between insulating layers 43 and 44. These interfaces are formed by stacking multiple green sheets, and depending on the stacking state, the interfaces may not be straight in cross-section or may be indistinct.

[0033] The mounting surface 40A of the insulating substrate 40 is, for example, disposed on the upper surface of the insulating layer 44. The opposite surface 40B of the insulating substrate 40 is, for example, disposed on the lower surface of the insulating layer 41. The opposite surface 40B is, for example, bonded to the upper surface of the base plate 20 using an adhesive (not shown).

[0034] (Structure of gas supply unit 50)

[0035] Multiple gas supply sections 50 are provided inside the base plate 20 and the electrostatic chuck 30. Each gas supply section 50 is formed to penetrate the base plate 20 in the thickness direction (vertical direction in the figure) and the electrostatic chuck 30 in the thickness direction (vertical direction in the figure). That is, each gas supply section 50 extends from the lower surface of the base plate 20 to the upper surface (i.e., the mounting surface 40A) of the electrostatic chuck 30. Each gas supply section 50 is formed to open downwards into the base plate 20 and upwards into the electrostatic chuck 30. For example, gas used to cool the adsorbed object held on the mounting surface 40A of the electrostatic chuck 30 is introduced into each gas supply section 50. An inert gas can be used as the cooling gas. For example, helium (He) gas, argon (Ar) gas, etc. can be used as inert gases.

[0036] like Figure 2 As shown, multiple gas supply units 50 are distributed on the mounting surface 40A of the electrostatic chuck 30 when viewed from above. In this example, eight gas supply units 50 are arranged along the outer periphery of the electrostatic chuck 30 when viewed from above. The number of gas supply units 50 can be appropriately determined as needed. For example, the number of gas supply units 50 can be set to approximately several tens to several hundred.

[0037] like Figure 1 As shown, each gas supply unit 50 has: a gas flow path 51 disposed on the base plate 20; and an air hole 60 disposed on the insulating substrate 40 of the electrostatic chuck 30. Each gas supply unit 50 is configured such that the gas flow path 51 and the air hole 60 communicate with each other, thereby extending from the lower surface of the base plate 20 to the mounting surface 40A of the insulating substrate 40. In each gas supply unit 50, the lower end of the gas flow path 51 serves as an inlet (inlet) for introducing inert gas from a gas supply source (not shown). In each gas supply unit 50, the upper end of the air hole 60 serves as an outlet (outlet) for discharging the inert gas introduced into the gas supply unit 50. In each gas supply unit 50, inert gas is introduced into the interior of the gas supply unit 50 through the gas flow path 51, and the inert gas is discharged from the upper end of the air hole 60 through the gas flow path 51 and the air hole 60. The inert gas discharged from the upper end of the vent 60 can, for example, cool the adsorbent by filling the space between the adsorbent placed on the mounting surface 40A and the mounting surface 40A.

[0038] (Structure of gas flow path 51)

[0039] Each gas flow path 51 is formed to penetrate the base plate 20 in the thickness direction. That is, each gas flow path 51 extends from the lower surface of the base plate 20 to the upper surface of the base plate 20. Each gas flow path 51 is formed to open downward and upward into the base plate 20.

[0040] (Structure of pore 60)

[0041] Each vent 60 is formed to penetrate the insulating substrate 40 of the electrostatic chuck 30 in the thickness direction (stack direction). Each vent 60 extends from the opposite side 40B of the insulating substrate 40 to the mounting surface 40A of the insulating substrate 40. Each vent 60 is formed to communicate with each gas flow path 51. Inert gas is introduced from each gas flow path 51 into each vent 60. Furthermore, the plurality of vents 60 have the same structure as each other. Therefore, in the following description, focus is placed on one vent 60 (refer to...). Figure 2 The specific structure of the pores 60 is explained using a single-dot dashed frame.

[0042] Each vent 60 has: one or more vent portions 61 that penetrate the insulating layer 41 in the thickness direction; an enlarged space 62 that expands the space in the planar direction; one or more vent portions 63 that penetrate the insulating layer 42 in the thickness direction; and an enlarged space 64 that expands the space in the planar direction. Each vent 60 also has: one or more vent portions 65 that penetrate the insulating layer 43 in the thickness direction; an enlarged space 66 that expands the space in the planar direction; and one or more vent portions 67 that penetrate the insulating layer 44 in the thickness direction. In this embodiment, each vent 60 has one vent portion 61, one enlarged space 62, one vent portion 63, one enlarged space 64, one vent portion 65, one enlarged space 66, and one vent portion 67. Each pore 60 is formed to extend from the opposite side 40B of the insulating substrate 40 to the mounting surface 40A of the insulating substrate 40 through holes 61, 63, 65, 67 and enlarged spaces 62, 64, 66. Here, the planar direction is a direction orthogonal to the thickness direction of the insulating substrate 40.

[0043] (Structure of hole 61)

[0044] The hole 61 is formed to open downwards towards the insulating substrate 40. The hole 61 communicates with the gas flow path 51. The hole 61 extends from the opposite surface 40B of the insulating substrate 40 towards the mounting surface 40A. For example, the hole 61 is formed to extend linearly along the thickness direction of the insulating substrate 40. The upper end of the hole 61 communicates with the enlarged space 62. The shape and size of the hole 61 can be arbitrary.

[0045] like Figure 3 and Figure 4 As shown, the planar shape of the hole 61 in this embodiment is circular. The planar dimensions of the hole 61 are smaller than the planar dimensions of the enlarged space 62. The diameter (opening diameter) of the hole 61 can be set to approximately 0.05 mm to 0.5 mm, for example.

[0046] (Structure of expanded space 62)

[0047] like Figure 1 As shown, an enlarged space 62 is disposed between insulating layer 41 and insulating layer 42. The enlarged space 62 is formed to be surrounded by insulating layer 41 and insulating layer 42. The enlarged space 62 is, for example, disposed on the upper surface of insulating layer 41. The enlarged space 62 is, for example, recessed upwards from the lower surface of insulating layer 42. The enlarged space 62 is formed not to penetrate insulating layer 42 in the thickness direction. The enlarged space 62 is, for example, open downwards towards insulating layer 42. The depth of the enlarged space 62 is less than the thickness of insulating layer 42. That is, the size of the enlarged space 62 along the thickness direction of insulating substrate 40 is smaller than the size of insulating layer 42 along the thickness direction. The depth of the enlarged space 62 is less than the diameter of hole 61. That is, the size of the enlarged space 62 along the thickness direction is smaller than the size of hole 61 along the planar direction. The size of the enlarged space 62 along the thickness direction can be, for example, set to approximately 0.02 mm to 0.15 mm.

[0048] like Figure 4 As shown, the enlarged space 62 is formed to extend from the hole 61 in the planar direction. The enlarged space 62 is formed to surround the holes 61 and 63 when viewed from above. When viewed from above, the enlarged space 62 extends into the area between the holes 61 and 63, and extends further outward than the holes 61 and 63. The shape and size of the enlarged space 62 can be arbitrary. In this embodiment, the planar shape of the enlarged space 62 is circular. The planar dimension of the enlarged space 62 is larger than the combined planar dimension of the holes 61 and 63. For example, the planar dimension of the enlarged space 62 can be set to approximately 5 to 12 times the planar dimension of the hole 61. The diameter of the enlarged space 62 can be set to approximately 1.0 mm to 3.0 mm.

[0049] (Structure of hole 63)

[0050] like Figure 1As shown, the lower end of the hole 63 communicates with the enlarged space 62. The hole 63 is formed, for example, to extend from the enlarged space 62 toward the mounting surface 40A. The hole 63 is formed, for example, to extend linearly along the thickness direction of the insulating substrate 40. The hole 63 is formed to extend from the enlarged space 62 to the upper surface of the insulating layer 42. The upper end of the hole 63 communicates with the enlarged space 64.

[0051] like Figure 4 As shown, the hole 63 is configured not to overlap with the hole 61 when viewed from above. For example, when viewed from above, the hole 63 is positioned at a position rotated 180 degrees from the hole 61 around the center point of the enlarged space 62. When viewed from above, the area of ​​the hole 63 that overlaps with the enlarged space 62 is configured to maximize the separation distance between the hole 61 and the hole 63.

[0052] The shape and size of the hole 63 can be any shape and size. In this embodiment, the planar shape of the hole 63 is circular. The planar dimensions of the hole 63 are, for example, set to be the same as the planar dimensions of the hole 61. The planar dimensions of the hole 63 are smaller than the planar dimensions of the enlarged space 62. The diameter of the hole 63 can be, for example, set to approximately 0.05 mm to 0.5 mm.

[0053] (Structure of expanded space 64)

[0054] like Figure 1 As shown, an enlarged space 64 is disposed between insulating layer 42 and insulating layer 43. The enlarged space 64 is formed to be surrounded by insulating layers 42 and 43. The enlarged space 64 is, for example, disposed on the upper surface of insulating layer 42. The enlarged space 64 is, for example, formed to be recessed upwards from the lower surface of insulating layer 43. The enlarged space 64 is formed not to penetrate insulating layer 43 in the thickness direction. The enlarged space 64 is, for example, formed to be open downwards towards insulating layer 43. The dimension of the enlarged space 64 along the thickness direction is smaller than the dimension of insulating layer 43 along the thickness direction. The dimension of the enlarged space 64 along the thickness direction is smaller than the dimension of the hole 63 along the planar direction. The dimension of the enlarged space 64 along the thickness direction can be, for example, set to approximately 0.02 mm to 0.15 mm.

[0055] like Figure 4 As shown, the enlarged space 64 is formed to extend from the hole 63 in the planar direction. The enlarged space 64 is formed to surround the holes 63 and 65 when viewed from above. When viewed from above, the enlarged space 64 extends into the region between the holes 63 and 65, and extends further outward than the holes 63 and 65. The shape and size of the enlarged space 64 can be arbitrary. In this embodiment, the planar shape of the enlarged space 64 is circular. Figure 3As shown, the enlarged space 64 is formed to overlap with the enlarged space 62 when viewed from above. For example, the enlarged space 64 is formed to completely overlap with the enlarged space 62 when viewed from above. The planar dimension of the enlarged space 64 is larger than the combined planar dimension of the hole 63 and the hole 65. For example, the planar dimension of the enlarged space 64 can be set to approximately 5 to 12 times the planar dimension of the hole 63. For example, the planar dimension of the enlarged space 64 is set to a size similar to that of the enlarged space 62. The diameter of the enlarged space 64 can be set to approximately 1.0 mm to 3.0 mm.

[0056] (Structure of hole 65)

[0057] like Figure 1 As shown, the lower end of the hole 65 communicates with the enlarged space 64. The hole 65 is formed, for example, to extend from the enlarged space 64 toward the mounting surface 40A. The hole 65 is formed, for example, to extend linearly along the thickness direction of the insulating substrate 40. The hole 65 is formed to extend from the enlarged space 64 to the upper surface of the insulating layer 43. The upper end of the hole 65 communicates with the enlarged space 66.

[0058] like Figure 4 As shown, the hole 65 is configured not to overlap with the hole 63 when viewed from above. For example, when viewed from above, the hole 65 is positioned at a position rotated 180 degrees from the hole 63 around the center point of the enlarged space 64. The area where the hole 65 overlaps with the enlarged space 64 when viewed from above is configured to maximize the separation distance between the hole 63 and the hole 65. For example, the hole 65 is configured to overlap with the hole 61 when viewed from above.

[0059] The shape and size of the hole 65 can be any shape and size. In this embodiment, the planar shape of the hole 65 is circular. The planar dimensions of the hole 65 are, for example, set to be the same as the planar dimensions of the hole 61. The planar dimensions of the hole 65 are smaller than the planar dimensions of the enlarged space 64. The diameter of the hole 65 can be, for example, set to approximately 0.05 mm to 0.5 mm.

[0060] (Structure of expanded space 66)

[0061] like Figure 1As shown, an enlarged space 66 is disposed between insulating layer 43 and insulating layer 44. The enlarged space 66 is formed to be surrounded by insulating layer 43 and insulating layer 44. The enlarged space 66 is, for example, disposed on the upper surface of insulating layer 43. The enlarged space 66 is, for example, formed to be recessed upwards from the lower surface of insulating layer 44. The enlarged space 66 is formed not to penetrate insulating layer 44 in the thickness direction. The enlarged space 66 is, for example, formed to be open downwards towards insulating layer 44. The dimension of the enlarged space 66 along the thickness direction is smaller than the dimension of insulating layer 44 along the thickness direction. The dimension of the enlarged space 66 along the thickness direction is smaller than the dimension of the hole 65 along the planar direction. The dimension of the enlarged space 66 along the thickness direction can be, for example, set to approximately 0.02 mm to 0.15 mm.

[0062] like Figure 4 As shown, the enlarged space 66 is formed to extend from the hole 65 in the planar direction. When viewed from above, the enlarged space 66 is formed to surround the holes 65 and 67. When viewed from above, the enlarged space 66 extends into the region between the holes 65 and 67, and extends further outward than the holes 65 and 67. The shape and size of the enlarged space 66 can be arbitrary. In this embodiment, the planar shape of the enlarged space 66 is circular. Figure 3 As shown, the enlarged space 66 is formed to overlap with enlarged spaces 62 and 64 when viewed from above. For example, the enlarged space 66 is formed to completely overlap with enlarged spaces 62 and 64 when viewed from above. The planar dimension of the enlarged space 66 is larger than the combined planar dimension of the hole 65 and the hole 67. For example, the planar dimension of the enlarged space 66 can be set to approximately 5 to 12 times the planar dimension of the hole 65. For example, the planar dimension of the enlarged space 66 is set to a size similar to that of the enlarged space 62. The diameter of the enlarged space 66 can be set to approximately 1.0 mm to 3.0 mm.

[0063] (Structure of hole 67)

[0064] like Figure 1 As shown, the lower end of the hole 67 communicates with the enlarged space 66. The hole 67 is formed, for example, to extend from the enlarged space 66 toward the mounting surface 40A. The hole 67 is formed, for example, to extend linearly along the thickness direction of the insulating substrate 40. The hole 67 extends from the enlarged space 66 to the upper surface of the insulating layer 44, i.e., the mounting surface 40A. The upper end of the hole 67 is formed to open upwards toward the insulating substrate 40. The upper end of the hole 67 is the outlet of the gas supply section 50, which discharges inert gas to the outside of the gas supply section 50.

[0065] like Figure 4As shown, the hole 67 is configured not to overlap with the hole 65 when viewed from above. For example, when viewed from above, the hole 67 is positioned at a position rotated 180 degrees from the hole 65 around the center point of the enlarged space 66. The area where the hole 67 overlaps with the enlarged space 66 when viewed from above is configured to maximize the separation distance between the hole 65 and the hole 67. For example, the hole 67 is configured to overlap with the hole 63 when viewed from above.

[0066] The shape and size of the hole 67 can be any shape and size. In this embodiment, the planar shape of the hole 67 is circular. The planar dimensions of the hole 67 are, for example, set to be the same as the planar dimensions of the hole 61. The planar dimensions of the hole 67 are smaller than the planar dimensions of the enlarged space 66. The diameter of the hole 67 can be, for example, set to approximately 0.05 mm to 0.5 mm.

[0067] like Figure 1 As shown, regarding the gas supply unit 50 described above, inert gas is introduced into the gas supply unit 50 through the gas flow path 51, causing the inert gas to flow into the orifice 61 through the gas flow path 51. Furthermore, in the gas supply unit 50, after the inert gas flowing into the enlarged space 62 through the orifice 61 moves in the planar direction within the enlarged space 62, it flows into the enlarged space 64 through the orifice 63. In the gas supply unit 50, after the inert gas flowing into the enlarged space 64 moves in the planar direction within the enlarged space 64, it flows into the enlarged space 66 through the orifice 65. In the gas supply unit 50, after the inert gas flowing into the enlarged space 66 moves in the planar direction within the enlarged space 66, it flows into the orifice 67, and is discharged from the gas supply unit 50 through the orifice 67. The inert gas discharged from the orifice 67 can, for example, cool the adsorbent object by filling the space between the lower surface of the adsorbent object placed on the mounting surface 40A and the mounting surface 40A.

[0068] (effect)

[0069] Next, the function of the substrate fixing device 10 will be explained.

[0070] The substrate holding device 10, for example, when disposed in a chamber (not shown), places the object to be adsorbed on the mounting surface 40A of the electrostatic chuck 30. Furthermore, by introducing a raw material gas into the chamber and applying a high-frequency voltage to the base plate 20, plasma is generated, and processing of the object to be adsorbed (e.g., a wafer) is performed. At this time, an inert gas, such as He gas, is introduced from a gas supply source (not shown) into the gas supply section 50, which is composed of a gas flow path 51 and vents 60. The inert gas is supplied sequentially through the gas flow path 51, vent 61, enlarged space 62, vent 63, enlarged space 64, vent 65, enlarged space 66, and vent 67 to the lower surface of the object to be adsorbed placed on the mounting surface 40A. In this plasma generation process, abnormal discharges sometimes occur within the gas supply section 50.

[0071] Here, when the vent is formed in a straight line along the thickness direction of the electrostatic chuck, as in existing electrostatic chucks, the path distance for the inert gas flow is shortened, resulting in a higher concentration of inert gas inside the vent. Therefore, when a high voltage is applied, the probability of collision between the plasma and inert gas trapped inside the vent increases, making it easier for abnormal discharges to occur inside the vent.

[0072] In contrast, in the electrostatic chuck 30 of this embodiment, the vent 60 is configured as follows: it has a hole 61 through which the insulating layer 41 penetrates in the thickness direction; an enlarged space 62 that expands the space of the vent 60 in the planar direction; and a hole 63 through which the insulating layer 42 penetrates in the thickness direction. Furthermore, the hole 61 and the hole 63 are configured not to overlap when viewed from above. According to this structure, by connecting the hole 61 and the hole 63 through the enlarged space 62, the path of the inert gas flow can be extended. As a result, the inert gas flows a longer distance than in the prior art, thus reducing the probability of collision between plasma and inert gas trapped inside the vent 60 compared to the prior art. Consequently, abnormal discharge within the vent 60 can be appropriately suppressed, and insulation damage caused by abnormal discharge can be appropriately suppressed.

[0073] Furthermore, the size of the enlarged space 62 along the thickness direction is set to be smaller than the size of the hole 61 along the planar direction. According to this structure, the enlarged space 62 can be formed narrowly in the thickness direction. Therefore, for example, when He gas is used as an inert gas, the movement of He molecules can be suppressed in the enlarged space 62, thus reducing the probability of He molecules colliding with each other. Specifically, compared to the case where the enlarged space 62 is formed to penetrate the insulating layer 42 in the thickness direction, the movement of He molecules within the enlarged space 62 can be suppressed, thus reducing the probability of He molecules colliding with each other. As a result, abnormal discharge within the pore 60 can be appropriately suppressed, and insulation damage caused by abnormal discharge can be appropriately suppressed.

[0074] (Manufacturing method of substrate fixing device 10)

[0075] Next, the manufacturing method of the substrate fixing device 10 will be described. Here, the manufacturing method of the electrostatic chuck 30 will be described in detail.

[0076] First of all, Figure 5 In the process shown, green sheets 71, 72, 73, and 74, composed of ceramic and organic materials, are prepared. Each green sheet 71, 72, 73, and 74 is, for example, a sheet-like structure formed by mixing alumina (alumina trioxide) with a binder, solvent, etc. The planar dimensions of each green sheet 71, 72, 73, and 74 are... Figure 1 The planar dimensions of the insulating substrate 40 shown correspond to those of the substrate. The green sheets 71, 72, 73, and 74 are respectively formed by firing in the processes described later. Figure 1 Insulating layers 41, 42, 43, and 44 are shown.

[0077] Next, in Figure 6 In the process shown, through holes 71X, 72X, 73X, and 74X are formed on the green sheets 71, 72, 73, and 74, respectively, through the green sheets 71, 72, 73, and 74 in the thickness direction. The through hole 71X is provided at the... Figure 1 The position corresponding to the hole 61 shown. The through hole 72X is provided at the position corresponding to... Figure 1 The position corresponding to the hole 63 shown. The through hole 73X is provided at the location corresponding to... Figure 1 The position corresponding to the hole 65 shown. The through hole 74X is provided at the location corresponding to... Figure 1 The position corresponding to the hole 67 shown. Furthermore, the through holes 71X, 72X, 73X, and 74X can be formed, for example, by laser processing or machining.

[0078] Next, in Figure 7In the process shown, resin slurry 81 is filled into the through hole 71X using a scraper or the like, and resin slurry 83 is filled into the through hole 72X. Similarly, resin slurry 85 is filled into the through hole 73X using a scraper or the like, and resin slurry 87 is filled into the through hole 74X. Resin slurries 81, 83, 85, and 87 are, for example, made of materials that can volatilize during the firing process described later. As materials for resin slurries 81, 83, 85, and 87, a mixture of resin and carbon can be used, for example.

[0079] Next, in Figure 8 In the illustrated process, resin paste 92 is formed on the upper surface of the green sheet 71, for example, by a printing method (screen printing), and resin paste 94 is formed on the upper surface of the green sheet 72. Similarly, resin paste 96 is formed on the upper surface of the green sheet 73, for example, by a printing method. The resin paste 92 is disposed on the surface of the green sheet 73. Figure 1 The position corresponding to the enlarged space 62 shown. Resin slurry 92 is positioned to overlap with resin slurries 81 and 83 when viewed from above. Resin slurry 94 is positioned relative to... Figure 1 The position corresponding to the enlarged space 64 shown. Resin slurry 94 is positioned to overlap with resin slurries 83 and 85 when viewed from above. Resin slurry 96 is positioned relative to... Figure 1 The position corresponding to the enlarged space 66 shown. Resin slurry 96 is positioned to overlap with resin slurries 85 and 87 when viewed from above. Similar to resin slurries 81, 83, 85, and 87, resin slurries 92, 94, and 96 are made of materials capable of volatilizing during the firing process described later. For example, a mixture of resin and carbon can be used as the material for resin slurries 92, 94, and 96. Furthermore, resin slurry 92 can be formed on the lower surface of green sheet 72. Additionally, resin slurry 94 can be formed on the lower surface of green sheet 73, and resin slurry 96 can also be formed on the lower surface of green sheet 74.

[0080] Next, in Figure 9 In the process shown, green sheets 72, 73, and 74 are sequentially placed on top of green sheet 71. At this time, green sheets 71, 72, 73, and 74 are aligned such that resin slurries 81, 83, 85, 87 and resin slurries 92, 94, and 96 overlap when viewed from above. Furthermore, green sheets 71, 72, 73, and 74 are layered to form structure 70. For example, green sheets 71, 72, 73, and 74 are bonded together by heating and pressurizing. Through this process, resin slurry 92 is placed between green sheets 71 and 72 (green sheets 72 are layered on top of green sheet 71 by sandwiching resin slurry 92 in the middle), resin slurry 94 is placed between green sheets 72 and 73, and resin slurry 96 is placed between green sheets 73 and 74.

[0081] Next, in Figure 10In the process shown, for Figure 9 The structure 70 shown is fired. As a result, the green sheets 71, 72, 73, and 74 are sintered to form insulating layers 41, 42, 43, and 44, respectively, forming an insulating substrate 40 with the aforementioned insulating layers 41, 42, 43, and 44 stacked on top of each other. The firing temperature is, for example, around 1500°C to 1600°C. Through this firing process, the... Figure 9 The resin slurries 81, 83, 85, 87, 92, 94, and 96 shown are evaporated and removed. As a result, a pore 60 is formed inside the insulating substrate 40, which connects the hole 61, the enlarged space 62, the hole 63, the enlarged space 64, the hole 65, the enlarged space 66, and the hole 67.

[0082] The electrostatic chuck 30 can be manufactured through the above manufacturing process.

[0083] In this embodiment, insulating layer 41 is an example of a first insulating layer, insulating layer 42 is an example of a second insulating layer, hole 61 is an example of a first hole, hole 63 is an example of a second hole, and hole 64 is an example of a third hole. Enlarged space 62 is an example of a first enlarged space, and enlarged space 64 is an example of a second enlarged space. Furthermore, green sheet 71 is an example of a first green sheet, green sheet 72 is an example of a second green sheet, through hole 71X is an example of a first through hole, and through hole 72X is an example of a second through hole. Resin slurry 81 is an example of a first resin slurry, resin slurry 83 is an example of a second resin slurry, and resin slurry 92 is an example of a third resin slurry.

[0084] (Effects of this implementation method)

[0085] Next, the effects of this implementation method will be explained.

[0086] (1) The electrostatic chuck 30 includes: an insulating substrate 40 having a mounting surface 40A for placing an object to be adsorbed and an opposite surface 40B disposed on the opposite side of the mounting surface 40A; and an air hole 60 that penetrates the insulating substrate 40 in the thickness direction. The air hole 60 includes: a hole portion 61 extending from the opposite surface 40B toward the mounting surface 40A; an enlarged space 62 communicating with the hole portion 61 and expanding the space of the air hole 60 in the planar direction; and a hole portion 63 communicating with the enlarged space 62 and extending from the enlarged space 62 toward the mounting surface 40A. The hole portion 61 is configured not to overlap with the hole portion 63 when viewed from above. The planar dimension of the enlarged space 62 is larger than the combined planar dimension of the hole portion 61 and the hole portion 63. The dimension of the enlarged space 62 along the thickness direction is smaller than the dimension of the hole portion 61 along the planar direction.

[0087] According to this structure, the aperture 61 and aperture 63 are connected by an enlarged space 62 that expands the space of the aperture 60 in the planar direction. This makes the path of the aperture 60 more complex and extends the flow distance of the inert gas. Therefore, the inert gas flows over a greater distance than in the prior art, thus reducing the probability of collision between plasma and inert gas trapped inside the aperture 60. As a result, abnormal discharges within the aperture 60 can be appropriately suppressed, and insulation damage caused by abnormal discharges can be appropriately suppressed.

[0088] (2) Furthermore, the size of the enlarged space 62 along the thickness direction is set to be smaller than the size of the hole 61 along the planar direction. According to this structure, the enlarged space 62 can be formed narrowly in the thickness direction. Therefore, for example, when He gas is used as an inert gas, the movement of He molecules within the enlarged space 62 can be suppressed, thus reducing the probability of He molecules colliding with each other. Specifically, compared to the case where the enlarged space 62 is formed to penetrate the insulating layer 42 in the thickness direction, the movement of He molecules within the enlarged space 62 can be suppressed, thus reducing the probability of He molecules colliding with each other. In this way, by providing the enlarged space 62, the path of the pore 60 can be extended, and by forming the enlarged space 62 narrowly in the thickness direction, the movement of He molecules within the enlarged space 62 can be suppressed. As a result, abnormal discharge within the pore 60 can be appropriately suppressed, and insulation damage caused by abnormal discharge can be appropriately suppressed.

[0089] (3) However, if the orifice 61 and orifice 63 are formed so that they do not overlap when viewed from above, it is also possible to form the overall shape of the vent 60 as a spiral. In this case, the enlarged space 62 is formed as a curved shape extending from the orifice 61 toward the orifice 63 when viewed from above. In this case, the inert gas flows in one direction in the spiral path.

[0090] In contrast, regarding the electrostatic chuck 30 of this embodiment, the enlarged space 62 is formed such that, when viewed from above, it extends into the region between the holes 61 and 63, and further outward than the holes 61 and 63. Therefore, compared to the case where the vent 60 is formed in a spiral shape, the planar dimension of the enlarged space 62 can be increased, allowing the enlarged space 62 to be formed wider in the planar direction. Thus, the space of the enlarged space 62 can be ensured to be wider relative to the amount of He molecules introduced into the vent 60. Therefore, the probability of He molecules colliding with each other within the enlarged space 62 can be appropriately reduced.

[0091] (4) The vent 60 also has: an enlarged space 64 that communicates with the vent portion 63 and expands the space of the vent 60 in the planar direction; and a vent portion 65 that communicates with the enlarged space 64 and extends from the enlarged space 64 toward the mounting surface 40A. The vent portion 65 is configured not to overlap with the vent portion 63 when viewed from above, and is configured to overlap with the vent portion 61.

[0092] According to this structure, the vent 60 is configured to connect the vent portion 61, the enlarged space 62, the vent portion 63, the enlarged space 64, and the vent portion 65. This allows for a more complex path for the vent 60, further extending the flow distance of the inert gas. Therefore, the inert gas flows over a longer distance compared to existing technologies, thus reducing the probability of collisions between plasma and inert gas trapped inside the vent 60.

[0093] (Example of amendment)

[0094] The above-described embodiments can be modified and implemented in the following ways. The above-described embodiments and the following modifications can be combined and implemented within the scope that are not technically contradictory.

[0095] • In the above embodiment, the planar shape of the expanded spaces 62, 64, and 66 is formed as a circle, but it is not limited to this. For example, the planar shape of the expanded spaces 62, 64, and 66 may also be formed as a polygon or an ellipse.

[0096] In the above embodiments, the planar shapes of the enlarged spaces 62, 64, and 66 are formed to be the same as each other, but this is not a limitation. For example, the planar shapes of the enlarged spaces 62, 64, and 66 may also be formed to be different from each other.

[0097] In the above embodiment, the number of holes 61 and 63 communicating with one enlarged space 62 is set to one, but the number of holes 61 and 63 is not particularly limited. Similarly, the number of holes 63 and 65 communicating with one enlarged space 64, and the number of holes 65 and 67 communicating with one enlarged space 66 are not particularly limited.

[0098] For example Figure 11 As shown, two or more holes 61 can be connected to one enlarged space 62, and two or more holes 63 can be connected to one enlarged space 62. Alternatively, two or more holes 63 can be connected to one enlarged space 64, and two or more holes 65 can be connected to one enlarged space 64. Furthermore, two or more holes 65 can be connected to one enlarged space 66, and two or more holes 67 can be connected to one enlarged space 66.

[0099] In this case, the two holes 61 are respectively configured not to overlap with the two holes 63 when viewed from above. The two holes 63 are respectively positioned, for example, when viewed from above, at a position rotated 90 degrees from the center point of each hole 61 about the center point of the enlarged space 62. The two holes 65 are respectively configured not to overlap with the two holes 63 when viewed from above, and are also configured to overlap with each of the two holes 61 when viewed from above. The two holes 65 are respectively positioned, for example, when viewed from above, at a position rotated 90 degrees from the center point of each hole 63 about the center point of the enlarged space 64. The two holes 67 are respectively configured not to overlap with the two holes 65 when viewed from above, and are also configured to overlap with each of the two holes 63 when viewed from above. The two holes 67 are respectively positioned, for example, when viewed from above, at a position rotated 90 degrees from the center point of each hole 65 about the center point of the enlarged space 66.

[0100] In the above embodiments, each vent 60 is configured to have three enlarged spaces 62, 64, and 66, but the number of enlarged spaces in each vent 60 is not limited to this. For example, the number of enlarged spaces in each vent 60 may be set to one or two, or to more than or equal to four. For example, the enlarged space in each vent 60 may be set to only be an enlarged space 62.

[0101] In the above embodiments, an adhesive layer can be used to bond insulating layer 41 and insulating layer 42 to each other. An adhesive layer can be used to bond insulating layer 42 and insulating layer 43 to each other. An adhesive layer can be used to bond insulating layer 43 and insulating layer 44 to each other.

[0102] In the above embodiments, the insulating substrate 40 may be configured with four insulating layers 41, 42, 43, and 44 stacked on top of each other, but it is not limited to this. For example, the insulating substrate 40 may be configured with two or three insulating layers stacked on top of each other. For example, the insulating substrate 40 may be configured with five or more insulating layers stacked on top of each other.

[0103] The structure of the electrostatic chuck 30 in the above embodiment is not particularly limited. For example, a heating element (heater) can be provided inside the insulating substrate 40, that is, heat is generated by applying voltage from outside the substrate fixing device 10, so that the mounting surface 40A of the insulating substrate 40 reaches a predetermined temperature. For example, an embossed structure can be provided on the mounting surface 40A of the insulating substrate 40.

[0104] The construction of the base plate 20 in the above embodiment is not particularly limited. For example, the shape of the gas flow path 51 is not particularly limited. In addition, a heater may be provided inside the base plate 20.

[0105] The substrate fixing device 10 described above is applied to semiconductor manufacturing apparatuses, such as dry etching apparatuses. Examples of dry etching apparatuses include parallel-plate type reactive ion etching (RIE) apparatuses. Furthermore, the substrate fixing device 10 can also be applied to semiconductor manufacturing apparatuses such as plasma CVD (Chemical Vapor Deposition) apparatuses and sputtering apparatuses.

[0106] Explanation of the label

[0107] 10. Substrate fixing device

[0108] 20 Base Plate

[0109] 30 electrostatic chucks

[0110] 40 Insulating substrate

[0111] 40A mounting surface

[0112] 40B Opposite side

[0113] 41 Insulation layer (first insulation layer)

[0114] 42 Insulation layer (second insulation layer)

[0115] 43 Insulation layer

[0116] 44 Insulation layer

[0117] 50 Gas Supply Department

[0118] 51 Gas Flow Path

[0119] 60 pores

[0120] Hole 61 (Hole 1)

[0121] 62 Expanding Space (First Expanding Space)

[0122] 63 Hole Section (Second Hole Section)

[0123] 64. Expanding Space (Second Expanding Space)

[0124] 65 Hole Section (3rd Hole Section)

[0125] 66 Expand space

[0126] 67 Hole

[0127] 71 raw film (first raw film)

[0128] 71X Through Hole (First Through Hole)

[0129] 72 raw slices (2nd raw slice)

[0130] 72X Through Hole (Second Through Hole)

[0131] 73, 74 raw slices

[0132] 73X, 74X Through Holes

[0133] 81 Resin Slurry (First Resin Slurry)

[0134] 83 Resin Slurry (Second Resin Slurry)

[0135] 85, 87, 94, 96 resin slurries

[0136] 92 Resin Slurry (Third Resin Slurry)

Claims

1. An electrostatic chuck, comprising: An insulating substrate having a mounting surface for placing an adsorbed object and an opposite surface disposed on the opposite side of the mounting surface; and The pores penetrate the insulating substrate in the thickness direction. The pores have: The first hole extends from the opposite side toward the mounting surface; A first enlarged space, which communicates with the first aperture, and expands the space of the vent in a plane orthogonal to the thickness direction; and The second hole communicates with the first enlarged space and extends from the first enlarged space toward the mounting surface. The first hole is configured so that it does not overlap with the second hole when viewed from above. The planar dimension of the first enlarged space is larger than the combined planar dimension of the first hole and the second hole. The size of the first enlarged space along the thickness direction is smaller than the size of the first hole along the planar direction.

2. The electrostatic chuck according to claim 1, wherein, The first expanded space is circular in planar shape. The first enlarged space is formed such that, when viewed from above, it extends into the area between the first hole and the second hole, and extends into an area further outward than the first hole and the second hole.

3. The electrostatic chuck according to claim 2, wherein, The pores have: The second enlarged space communicates with the second hole and expands the space of the vent in the planar direction; as well as The third hole communicates with the second enlarged space and extends from the second enlarged space toward the mounting surface. The third hole is configured not to overlap with the second hole when viewed from above, but to overlap with the first hole.

4. The electrostatic chuck according to claim 3, wherein, When viewed from above, the second enlarged space is configured to completely overlap with the first enlarged space.

5. The electrostatic chuck according to claim 1, wherein, The vent has one first vent portion, one first enlarged space, and one second vent portion. When viewed from above, the second hole is positioned at a point 180 degrees rotated from the first hole around the center point of the first enlarged space.

6. The electrostatic chuck according to claim 1, wherein, The insulating substrate has: a first insulating layer having the opposite side; and a second insulating layer stacked on the first insulating layer. The first hole is formed such that the first insulating layer penetrates through it in the thickness direction. The first enlarged space is formed on the upper surface of the first insulating layer, and is formed to be recessed from the lower surface of the second insulating layer upwards. The second hole is formed to penetrate the second insulating layer in the thickness direction.

7. The electrostatic chuck according to claim 6, wherein, The pores have: Two of the first holes penetrate the first insulating layer in the thickness direction; A first enlarged space is disposed between the first insulating layer and the second insulating layer; and Two of the second holes penetrate the second insulating layer in the thickness direction. The two first holes are connected to the one first enlarged space. The two second holes are connected to the one first enlarged space. The two first holes are respectively configured so that they do not overlap with the two second holes when viewed from above.

8. A substrate fixing device, comprising: The electrostatic chuck according to any one of claims 1 to 7; and A base plate that engages with the opposite side of the electrostatic chuck.

9. A method for manufacturing an electrostatic chuck, comprising the following steps: Prepare the first and second raw films; A first through hole is formed in the thickness direction to penetrate the first green sheet, and a second through hole is formed in the thickness direction to penetrate the second green sheet; The first resin slurry is filled into the first through hole, and the second resin slurry is filled into the second through hole; A third resin slurry is formed on the upper surface of the first green sheet or the lower surface of the second green sheet, such that it overlaps with the first resin slurry and the second resin slurry when viewed from above. The second green sheet is laminated on the first green sheet by sandwiching the third resin slurry in between; and The first and second green sheets, which are stacked on top of each other, are fired. In the firing process, the first resin slurry, the second resin slurry, and the third resin slurry are volatilized, thereby forming pores having a first pore, a first enlarged space, and a second pore. The first pore penetrates the first green sheet in the thickness direction. The first enlarged space communicates with the first pore. The second pore communicates with the first enlarged space and penetrates the second green sheet in the thickness direction.

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