Keeping device

Abstract

To provide a keeping device including a keeping substrate having a plurality of lateral flow channel parts with excellent workability having different depths.SOLUTION: A keeping device 100 of the present invention includes a keeping substrate 10 including a plate-shaped member 11 having a first surface S1 and a second surface S2, and a gas flow channel 12 including a gas outflow port 12b that opens on the first surface S1 side and a gas inflow port 12a that opens on the second surface S2 side and formed inside the plate-shaped member 11. The gas flow channel 12 includes a first lateral flow channel part 131 and a second lateral flow channel part 132 extending in parallel to the first surface S1. In a cross section 110 obtained by cutting the first lateral flow channel part 131 and the second lateral flow channel part 132 in a thickness direction of the keeping substrate 10, the depth D1 of the first lateral flow channel part 131 is deeper than the depth D2 of the second lateral flow channel part 132. A bottom surface 131a of the first lateral flow channel part 131 has an arc-like shape or an elliptical arc-like shape that swells to the second surface S2 side. A bottom surface 132a of the second lateral flow channel part 132 has a linear shape.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a retaining device. [Background technology]

[0002] An example of a holding device that holds a wafer (semiconductor wafer) during semiconductor manufacturing is an electrostatic chuck (see Patent Document 1). The electrostatic chuck includes a holding substrate (ceramic substrate) made primarily of insulating ceramics (e.g., alumina), and the wafer is held on the surface of the holding substrate by electrostatic attraction. The electrostatic attraction is generated by applying a voltage to a chuck electrode provided inside the holding substrate.

[0003] In this type of electrostatic chuck, a heat transfer gas such as helium gas is supplied between the holding substrate and the wafer during plasma processing such as plasma etching to remove heat from the wafer. For this reason, a gas flow path is formed inside the holding substrate of the electrostatic chuck to allow the heat transfer gas supplied from the outside to flow toward the wafer.

[0004] The gas flow path includes a vertical flow path portion extending in the thickness direction of the holding substrate and a horizontal flow path portion extending in the planar direction (i.e., the direction perpendicular to the thickness direction). As shown in Patent Document 2, the horizontal flow path portion in the holding substrate has a flat top surface and an arc-shaped or elliptical bottom surface in a cross section cut in the thickness direction.

[0005] Conventionally, the bottom surfaces of the horizontal flow passages provided inside the support substrate were all processed to have the same shape (arc-shaped, etc.) regardless of differences in flow passage size (flow passage width, depth, etc.) This was because, when forming the gas flow passages (horizontal flow passages, etc.), unsintered green sheets were processed using a common processing tool of the same shape for the purpose of simplifying the process. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4959905 [Patent Document 2] Japanese Patent Publication No. 2022-68650 Summary of the Invention [Problem to be solved by the invention]

[0007] It may be necessary to adjust the flow rate of the heat transfer gas flowing through the horizontal flow passage depending on the location where the horizontal flow passage is formed. For example, a horizontal flow passage provided in a location of the holding substrate where heat is likely to build up is desired to be deeper than other horizontal flow passages. Horizontal flow passages requiring such depth have traditionally been formed using a processing tool with a rounded tip, with an arc-shaped bottom that bulges out significantly. However, if a processing tool suitable for a deep horizontal flow passage is used to form a shallow horizontal flow passage, for example, the processing accuracy of the shallow horizontal flow passage deteriorates.

[0008] An object of the present invention is to provide a holding device including a holding substrate having a plurality of lateral flow passage portions which are different in depth from one another and which can be processed with excellent precision. [Means for solving the problem]

[0009] The means for solving the above problems are as follows: <1> a holding device including a holding substrate having a plate-like member including a first surface and a second surface disposed on the opposite side of the first surface, and a gas flow path formed inside the plate-like member, the gas flow path including a gas outlet opening on the first surface side and a gas inlet opening on the second surface side, wherein the gas flow path has a first lateral flow path section and a second lateral flow path section extending parallel to the first surface, and in a cross section obtained by cutting the first lateral flow path section and the second lateral flow path section in a thickness direction of the holding substrate, the depth of the first lateral flow path section is deeper than the depth of the second lateral flow path section, and the bottom surface of the first lateral flow path section has a circular arc shape or an elliptical arc shape that bulges toward the second surface side; The bottom surface of the second horizontal flow path portion is a linear holding device.

[0010] <2> When viewed from the first surface side, the width of the second horizontal flow path portion is larger than the width of the first horizontal flow path portion. <1> The holding device according to claim 1.

[0011] <3> The first horizontal flow path portion and the second horizontal flow path portion are connected to each other and communicate with each other. <1> or <2> The holding device according to claim 1. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a holding device including a holding substrate having a plurality of lateral flow passage portions which are different in depth from one another and have excellent processing precision. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view schematically illustrating an external configuration of a holding device according to a first embodiment; [Figure 2] FIG. 1 is a cross-sectional view schematically illustrating the internal structure of a holding device according to a first embodiment. [Figure 3] FIG. 10 is an explanatory view showing a state in which the first lateral flow path section and the second lateral flow path section formed in the plate-shaped member of the holding substrate are seen through a plan view from the first surface side. [Figure 4] 1 is a schematic explanatory diagram showing cross sections of the first horizontal flow path section and the second horizontal flow path section cut in the thickness direction of the holding substrate; [Figure 5] Schematic explanatory diagram showing a manufacturing method of a holding substrate [Figure 6] Schematic explanatory diagram showing a manufacturing method of a holding substrate [Figure 7] FIG. 1 is an explanatory diagram schematically illustrating a processing tool for forming a groove for a first horizontal flow path portion in a laminate of green sheets, and a processing tool for forming a groove for a second horizontal flow path portion. [Figure 8] FIG. 1 is an explanatory diagram showing a state in which grooves for a first horizontal flow path section and grooves for a second horizontal flow path section are formed in a laminate of green sheets. [Figure 9]FIG. 1 is an explanatory diagram showing a state in which a filler material is filled into a groove for a first horizontal flow path portion and a groove for a second horizontal flow path portion formed in a laminate of green sheets. [Figure 10] FIG. 1 is an explanatory diagram showing a state in which a second laminate is formed by laminating another green sheet laminate on a green sheet laminate. [Figure 11] 10A and 10B are explanatory views each showing a cross section of a first horizontal flow path section and a second horizontal flow path section according to a second embodiment, the cross section being cut in the thickness direction of a holding substrate. [Figure 12] FIG. 10 is an explanatory view showing a state in which a first lateral flow path section and a second lateral flow path section formed in a plate-like member of a holding substrate according to a third embodiment are seen through a plan view from a first surface side. [Figure 13] FIG. 10 is an explanatory diagram showing the positional relationship in the height direction between the first horizontal flow path section and the second horizontal flow path section according to another embodiment. [Figure 14] FIG. 10 is a cross-sectional view schematically illustrating the internal structure of a holding device according to Reference Example 1. [Figure 15] FIG. 10 is a cross-sectional view schematically illustrating the internal structure of a holding device according to Reference Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0014] <Embodiment 1> A holding device 100 according to a first embodiment will be described below with reference to Figs. 1 to 10. The holding device 100 is an electrostatic chuck that attracts and holds an object (e.g., a wafer W) by electrostatic attraction. The electrostatic chuck is used as a table on which the wafer W is placed, for example, in a process of performing etching using plasma in a decompressed chamber.

[0015] FIG. 1 is a perspective view schematically illustrating the external configuration of a holding device 100 according to the first embodiment, and FIG. 2 is a cross-sectional view schematically illustrating the internal structure of the holding device 100 according to the first embodiment. The holding device 100 includes a disk-shaped holding substrate (ceramic substrate) 10 and a disk-shaped base member 20 that is larger than the holding substrate 10. For example, if the holding substrate 10 is disk-shaped with a diameter of 300 mm and a thickness of 3 mm, the base member 20 is set to be disk-shaped with a diameter of 340 mm and a thickness of 20 mm. Note that the holding substrate 10 and the base member 20 may each be provided with a positioning portion (such as a recess or projection) for mutual alignment.

[0016] The holding substrate 10 and the base member 20 are stacked one on top of the other in the vertical direction, with the holding substrate 10 disposed on the upper side and the base member 20 disposed on the lower side. The holding substrate 10 and the base member 20 are bonded to each other by a bonding material 30 interposed therebetween.

[0017] The holding substrate 10 has a substantially circular first surface S1 disposed on the upper side, and a substantially circular second surface S2 disposed on the opposite side (i.e., the lower side) of the first surface S1 and facing the base member 20. The base member 20 has a substantially circular third surface S3 disposed on the upper side and facing the second surface S2 of the holding substrate 10, and a substantially circular fourth surface S4 disposed on the opposite side (i.e., the lower side) of the third surface S3. The above-mentioned bonding material 30 is sandwiched between the second surface S2 of the holding substrate 10 and the third surface S3 of the base member 20 and is spread out in a layer.

[0018] The holding substrate 10 includes a disk-shaped plate-like member 11 and a substrate-side gas flow path (an example of a gas flow path) 12 formed inside the plate-like member 11. The upper surface of the plate-like member 11 serves as a first surface S1 of the holding substrate 10. The lower surface of the plate-like member 11 serves as a second surface S2 of the holding substrate 10.

[0019] The plate-shaped member 11 is a plate-shaped (disk-shaped) insulating member whose main component is ceramic. In this specification, the term "main component" refers to the component with the highest content (for example, a content of 50% by volume or more). In this embodiment, the plate-shaped member 11 is made of alumina (Al2O3). In other embodiments, the plate-shaped member 11 may be made of other ceramics such as aluminum nitride (AlN).

[0020] The substrate-side gas flow path (an example of a gas flow path) 12 constitutes a part of a flow path 60 provided in the holding device 100 for flowing an inert gas (for example, helium gas, which is a heat-conductive gas). The substrate-side gas flow path 12 is formed inside the plate-like member 11 of the holding substrate 10. The substrate-side gas flow path 12 is made up of holes penetrating the holding substrate 10, including a gas inlet 12a opening to the second surface S2 of the holding substrate 10 and a gas outlet 12b opening to the first surface S1. When an inert gas is supplied from the gas inlet 12a, the inert gas passes through the substrate-side gas flow path 12 and is finally discharged to the outside from the gas outlet 12b.

[0021] As shown in FIG. 2, the substrate-side gas flow path 12 includes a first vertical flow path section 120, a horizontal flow path section 130, and a second vertical flow path section 140.

[0022] The first vertical flow path section 120 includes a gas outlet 12b that opens on the first surface S1 side, and is a flow path that extends from the gas outlet 12b to the second surface S2 side along the thickness direction of the plate-like member 11. The first vertical flow path section 120 has a substantially cylindrical shape that extends in the vertical direction.

[0023] The horizontal flow path section 130 is a flow path that is connected to the first vertical flow path section 120 and extends parallel to the first surface S1. The downstream side of the horizontal flow path section 130 is connected to the upstream side of the first vertical flow path section 120. In the substrate-side gas flow path 12, the gas inlet 12a side is the upstream side, and the gas outlet 12b is the downstream side. As will be described later, the horizontal flow path section 130 includes a first horizontal flow path section 131 and a second horizontal flow path section 132.

[0024] The second vertical flow path section 140 includes a gas inlet 12a that opens to the second surface S2, and is a flow path that extends from the gas inlet 12a to the first surface S1 side along the thickness direction of the plate-like member 11 (the direction from the first surface S1 side to the second surface S2 side). The downstream side of the second vertical flow path section 140 is connected to the upstream side of the horizontal flow path section 130. The gas inlet 12a forms the inlet of the substrate-side gas flow path 12. The second vertical flow path section 140 has a substantially cylindrical shape that extends in the vertical direction.

[0025] The holding substrate 10 also includes a gas-permeable porous body 70, primarily composed of ceramic, which fills the first vertical flow path section 120, which is part of the substrate-side gas flow path 12. The porous body 70 is a gas-permeable member primarily composed of insulating ceramic and containing a large number of pores. The porous body 70 fills each of the first vertical flow path sections 120 in the substrate-side gas flow path 12. The porous body 70 is generally cylindrical and extends in the vertical direction (thickness direction of the holding substrate 10), and has a network-like ventilation path formed therein for passing an inert gas. The ventilation path is composed of a large number of interconnected pores within the porous body 70. The pores are formed as traces left by the burning (disappearance) of a particulate pore-forming material during the manufacturing (firing) of the porous body 70. Examples of the pore-forming material include synthetic resin beads and carbon powder.

[0026] The porous body 70 is filled in the first vertical flow path section 120 so as to form a space below it. The upper end surface 70a of the porous body 70 is circular and exposed from the gas outlet port 12b. The space is formed on the downstream side of the horizontal flow path section 130. In this embodiment, the first surface S1 and the upper end surface 70a are arranged to be flush with each other. The porous body 70 and the peripheral wall portion constituting the first vertical flow path section 120 are joined together by sintering. The lower end surface of the porous body 70 faces the space within the horizontal flow path section 130, and the inert gas supplied from the upstream side of the substrate-side gas flow path (gas flow path) 12 is supplied into the porous body 70 from the lower end surface.

[0027] The holding substrate 10 further includes a chuck electrode 40, which is an electrode member. The chuck electrode 40 is generally planar (layered) and substantially parallel to the first surface S1. The chuck electrode 40 is made of a conductive material, such as tungsten, molybdenum, or platinum. As shown in FIG. 2, the chuck electrode 40 is disposed inside the holding substrate 10 (plate-like member 11) on the first surface S1 side. The chuck electrode 40 is connected to an external power supply via a terminal or the like. When power is supplied to the chuck electrode 40, an electrostatic attraction force is generated, and the wafer W is attracted and held to the first surface S1 of the holding substrate 10 by this electrostatic attraction force. In other embodiments, a high-frequency electrode or a heater electrode may be provided as the electrode member.

[0028] 1 and 2, a plurality of gas outlet ports 12b are provided on the first surface S1 of the holding substrate 10. The outer peripheral edge of the first surface S1 is formed in a circular ring shape and protrudes slightly upward compared to the inner portion thereof. Therefore, when a wafer W is held by suction on the first surface S1, a gap G is formed between the wafer W and the inner portion of the first surface S1, as shown in FIG. 2. A plurality of protrusions (mesas) (not shown) are formed on the first surface S1.

[0029] The base member 20 is mainly made of, for example, a metal (aluminum, aluminum alloy, etc.), a composite of metal and ceramics (Al-SiC), or ceramics (SiC).

[0030] 2, a coolant flow path 21 is provided inside the base member 20. A coolant (e.g., a fluorine-based inert liquid, water, etc.) is caused to flow through the coolant flow path 21, thereby cooling plasma heat. When the coolant flows through the coolant flow path 21, the base member 20 is cooled, and the holding substrate 10 is cooled by heat transfer (heat dissipation) between the base member 20 and the holding substrate 10 via the bonding material 30. As a result, the wafer W held on the first surface S1 of the holding substrate 10 is cooled.

[0031] A base-side gas flow path 22 that constitutes a part of the flow path 60 is provided inside the base member 20. The base-side gas flow path 22 is generally in the form of a through hole extending in the thickness direction of the base member 20, and includes an inlet 22a that opens to the fourth surface S4 of the base member 20 and an outlet 22b that opens to the third surface S3 of the base member 20. The inlet 22a serves as the inlet of the base-side gas flow path 22, and also serves as the inlet of the entire flow path 60 provided in the holding device 100.

[0032] The bonding material 30 is made of, for example, a bonding sheet containing a silicone-based organic bonding agent, an inorganic bonding agent, or an Al-based metal adhesive. The bonding material 30 preferably has high adhesive strength to both the holding substrate 10 and the base member 20, as well as high pressure resistance and thermal conductivity.

[0033] The bonding material 30 also has a bonding-side gas flow passage 31 that constitutes part of the flow passage 60. The bonding-side gas flow passage 31 is made of a hole that penetrates the layer-like bonding material 30 in the thickness direction.

[0034] The flow path 60 supplies an inert gas (such as helium gas) to the first surface S1 side of the holding device 100. As described above, the first surface S1 is provided with a large number of gas outlets 12b, which are outlets of the flow path 60, and the inert gas is supplied to the first surface S1 side by being discharged from each gas outlet 12b. As described above, the flow path 60 includes the base-side gas flow path 22, the bonding-side gas flow path 31, and the substrate-side gas flow path (gas flow path) 12.

[0035] A plurality of inlets 22a of the flow path 60 are provided on the fourth surface S4 of the base member 20. When an inert gas (arrow H in FIG. 2) is supplied from each inlet 22a, the inert gas sequentially passes through the base-side gas flow path 22, the bonding-side gas flow path 31, and the substrate-side gas flow path (gas flow path) 12 connected to each inlet 22a, and is finally discharged from a plurality of gas outlets 12b provided on the first surface S1.

[0036] The outlet 22b of the base-side gas flow passage 22 is connected to an opening on the lower side (base member 20 side) of the bonding-side gas flow passage 31. In addition, an opening on the upper side (holding substrate 10 side) of the bonding-side gas flow passage 31 is connected to a gas inlet 12a of the substrate-side gas flow passage (gas flow passage) 12. A plurality of gas inlet 12a of the substrate-side gas flow passage (gas flow passage) 12 is provided on the second surface S2 of the holding substrate 10.

[0037] The second vertical flow path section 140, which includes the gas inlet 12a of the substrate-side gas flow path (gas flow path) 12, is connected to a plurality of horizontal flow path sections 130 on its downstream side. Each horizontal flow path section 130 is connected to a first vertical flow path section 120. In other words, the substrate-side gas flow path (gas flow path) 12 is branched into a plurality of paths from the upstream side to the downstream side inside the holding substrate 10 (plate-like member 11).

[0038] 3 and 4, the first horizontal flow path section 131 and the second horizontal flow path section 132 included in the horizontal flow path section 130 will be described in detail. Fig. 3 is an explanatory diagram showing the first horizontal flow path section 131 and the second horizontal flow path section 132 formed in the plate-like member 11 of the holding substrate 10 as seen perspectively from the first surface S1 side, and Fig. 4 is an explanatory diagram schematically showing cross sections 110 of the first horizontal flow path section 131 and the second horizontal flow path section 132 cut in the thickness direction of the holding substrate 10.

[0039] The first horizontal flow path section 131 and the second horizontal flow path section 132 each extend parallel to the first surface S1. On a cut surface 110 obtained by cutting the first horizontal flow path section 131 and the second horizontal flow path section 132 in the thickness direction of the holding substrate 10 (plate-like member 11), as shown in Fig. 4, the depth D1 of the first horizontal flow path section 131 is formed to be deeper than the depth D2 of the second horizontal flow path section.

[0040] The depth D1 of the first cross-flow path portion 131 is the length (maximum length) from the ceiling surface 131b to the bottom surface 131a of the first cross-flow path portion 131. Also, the depth D2 of the second cross-flow path portion 132 is the length (maximum length) from the ceiling surface 132b to the bottom surface 132a of the second cross-flow path portion 132. Note that the depth D1 (mm) of the first cross-flow path portion 131 is set, for example, to 0.2 < D1 ≤ 1.3, and the depth D2 (mm) of the second cross-flow path portion 132 is set, for example, to 0 < D2 ≤ 0.2.

[0041] And, in the cut surface 110, the bottom surface 131a of the first cross-flow path portion 131 has an arc shape that bulges toward the second surface S2 side (the lower side in FIG. 4). In other embodiments, the bottom surface of the first cross-flow path portion 131 may have an elliptical arc shape that bulges toward the second surface S2 side. Also, in the cut surface 110, the bottom surface 132a of the second cross-flow path portion 132 has a linear shape extending in the width direction (the left-right direction in FIG. 4).

[0042] Also, as shown in FIGS. 3 and 4, when viewed in plan from the first surface S1 side, the width L2 of the second cross-flow path portion 132 is formed to be larger than the width L1 of the first cross-flow path portion 131.

[0043] The width L1 of the first cross-flow path portion 131 is the length of the first cross-flow path portion 131 in the direction orthogonal to the longitudinal direction when the direction in which the first cross-flow path portion 131 extends is taken as the longitudinal direction when viewed in plan from the first surface S1 side. The width L1 (mm) of the first cross-flow path portion 131 is set, for example, to 1.5 ≤ L1 ≤ 2.0. The width L2 of the second cross-flow path portion 132 is the length of the second cross-flow path portion 132 in the direction orthogonal to the longitudinal direction when the direction in which the second cross-flow path portion 132 extends is taken as the longitudinal direction when viewed in plan from the first surface S1 side. The width L2 (mm) of the second cross-flow path portion 132 is set, for example, to 5.2 ≤ L2 ≤ 6.2.

[0044] The first cross-flow path portion 131 is formed using a processing tool with a rounded tip, as will be described later. In contrast, the second cross-flow path portion 132 is formed using a processing tool with a pointed tip, as will be described later.

[0045] 4, the first horizontal flow path section 131 and the second horizontal flow path section 132 are arranged to be at approximately the same height on the cross section 110. In this embodiment, the height position of the ceiling surface 131b of the first horizontal flow path section 131 and the height position of the ceiling surface 132b of the second horizontal flow path section 132 are arranged to be approximately the same. Note that in other embodiments, the height position of the bottom surface 131a (the lowest part) of the first horizontal flow path section 131 and the height position of the bottom surface 132a of the second horizontal flow path section 132 may be arranged to be approximately the same.

[0046] Next, an example of a manufacturing method for the holding device 100 of this embodiment will be described. First, a manufacturing method for the holding substrate 10 constituting the holding device 100 will be described with reference to Figs. 5 to 10. Figs. 5 and 6 are explanatory diagrams that schematically show a manufacturing method for the holding substrate 10. This manufacturing method for the holding substrate 10 is an application of a sheet lamination method that uses green sheets (ceramic green sheets). In Figs. 5 and 6, the lower side (second surface S2 side) of the holding substrate 10 corresponds to the upper side of each figure, and the upper side (first surface S1 side) of the holding substrate 10 corresponds to the lower side of each figure.

[0047] 5(A), a first laminate 80a is formed by laminating a plurality of green sheets for forming the plate-like members 11 of the holding substrate 10. Note that a conductor layer 9 is formed on a predetermined green sheet constituting the first laminate 80a, and such a green sheet is laminated on other green sheets.

[0048] The slurry for the green sheets can be obtained by, for example, mixing a mixture containing alumina powder, an acrylic binder, a dispersant, a plasticizer, etc., with an organic solvent added, using a ball mill. This slurry is formed into a sheet using a casting device, and then the formed product is dried to obtain multiple green sheets.

[0049] The metallization paste for forming the conductor layer 9 can be obtained by adding conductive powder such as tungsten or molybdenum to a mixture of alumina powder, an acrylic binder, and an organic solvent, and kneading the mixture. The metallization paste is printed using, for example, a screen printing device, to form the conductor layer 9 on a specific green sheet.

[0050] 5(B), holes 81 for forming first vertical flow path sections 120 are formed in predetermined locations of the first laminate 80a. The holes 81 are cylindrical and penetrate the first laminate 80a in the thickness direction. The holes 81 are formed in predetermined locations of the first laminate 80a using a known processing device (router, etc.).

[0051] Next, as shown in FIG. 5(C), the holes 81 of the first laminate 80a are filled with a porous body paste 7 for forming the porous bodies 70. The porous body paste 7 is obtained, for example, by kneading a mixture containing alumina powder, a pore-forming material, a binder, an organic solvent, etc. Methods for filling the holes 81 with the porous body paste 7 include, for example, a method using an injection molding device and a method using a screen printing device. The first laminate 80a, in which the holes 81 have been filled with the porous body paste 7, is then dried as appropriate.

[0052] 6(D), the first laminate 80a and the second laminate 80b are laminated together. The second laminate 80b is made of a plurality of green sheets laminated together. The second laminate 80b has holes 82 for forming the second vertical flow path section 140 and grooves 83 for forming the horizontal flow path section 130 at predetermined locations.

[0053] 7 to 10, a method for manufacturing the second laminate 80b having grooves 83 for forming the horizontal flow path section 130 will be described. Fig. 7 is an explanatory diagram schematically showing a processing tool 91 for forming grooves 183 for the first horizontal flow path section 131 in a laminate 80b1 of green sheets, and a processing tool 92 for forming grooves 283 for the second horizontal flow path section 132.

[0054] 7, above a stack 80b1 of a plurality of (for example, about 10) green sheets, a processing tool 91 for forming the grooves 183 for the first horizontal flow path section 131 and a processing tool 92 for forming the grooves 283 for the second horizontal flow path section 132 are arranged. In the case of this embodiment, the grooves 183 for the first horizontal flow path section 131 and the grooves 283 for the second horizontal flow path section 132, which have different depths and bottom shapes, are formed using different processing tools.

[0055] The processing tool 91 is used to form the grooves 183 for the first horizontal flow path section 131 in the green sheet stack 80b1, and has a rod shape with a rounded tip 91a. The processing tool 91 is suitable for forming relatively deep flow paths. In contrast, the processing tool 92 is used to form the grooves 283 for the second horizontal flow path section 132 in the green sheet stack 80b1, and has a rod shape (e.g., a flat plate shape) with an angular tip 92a. The processing tool 92 is suitable for forming relatively shallow flow paths. In FIG. 7, the area below the processing tool 91 where the grooves 183 for the first horizontal flow path section 131 will be formed is indicated by a dashed line, and the area below the processing tool 92 where the grooves 283 for the second horizontal flow path section 132 will be formed is indicated by a dashed line.

[0056] The processing tool 91 and the processing tool 92 can be moved independently. The processing tool 91 and the processing tool 92 can be moved vertically and horizontally. The processing tool 91 and the processing tool 92 can also be moved in a direction from the front side of the paper to the back side of the paper (front-to-back direction on the paper).

[0057] 8 is an explanatory diagram schematically illustrating a state in which a groove 183 for the first horizontal flow path section 131 and a groove 283 for the second horizontal flow path section 132 are formed in a laminate 80b1 of green sheets. As shown in FIG. 8, the laminate 80b1 is formed with the groove 183 for the first horizontal flow path section 131 and the groove 283 for the second horizontal flow path section 132. The groove 183 is formed by scraping the surface of the laminate 80b1 with the rounded tip 91a of the processing tool 91, and the bottom surface 183a of the groove 183 is arc-shaped and bulges downward. The groove 283 is formed by scraping the surface of the laminate 80b1 with the angular tip 92a of the processing tool 92, and the bottom surface 283a of the groove 283 is linear.

[0058] 9 is an explanatory diagram schematically illustrating a state in which a groove 183 for the first horizontal flow path section 131 and a groove 283 for the second horizontal flow path section 132 formed in a laminate 80b1 of green sheets are filled with a filler 84. The filler 84 is, for example, a carbon paste or the like, and is a material that is burned (disappears) during firing. By filling the grooves 83 (groove 183, groove 283) with the filler 84 in this manner, the grooves 83 are prevented from being crushed, and the shape of the grooves 83 is maintained.

[0059] 10 is an explanatory diagram showing a state in which a laminate 80b2 of another green sheet is laminated on a laminate 80b1 of green sheets to form a second laminate 80b. Note that the laminate 80b2 has holes 82 and the like formed therein to form the second vertical flow path section 140.

[0060] Returning to FIG. 6(D), the laminate of the first laminate 80a and the second laminate 80b will now be described. The laminate consisting of the first laminate 80a and the second laminate 80b is made of, for example, a stack of 20 green sheets, which are thermocompression bonded together. The outer periphery of the laminate may be cut as appropriate. The laminate is then machined to produce a disk-shaped compact. The resulting compact is then degreased and fired, and the degreased and fired compact is then fired (main firing) to obtain a fired body.

[0061] Then, a mask is placed on the surface of the sintered body to shield the portion corresponding to the convex outer periphery, and the surface is subjected to shot blasting, for example, by projecting ceramic particles, to form a convex outer periphery on the surface of the sintered body. The surface of the sintered body is then polished or otherwise processed to obtain a holding substrate 10 having a plate-like member 11, as shown in FIG. 6(E).

[0062] The manufacturing method of the base member 20 is basically the same as the manufacturing method of the conventional product. Therefore, a detailed description thereof will be omitted. After the holding substrate 10 and the base member 20 are manufactured, they are bonded together using a bonding material 30. The bonding of the holding substrate 10 and the base member 20 with the bonding material 30 is basically the same as the bonding in the conventional product. Therefore, a detailed description thereof will be omitted. In this way, the holding device 100 is manufactured.

[0063] As described above, in the holding device 100 of this embodiment, the first horizontal flow path section 131 and the second horizontal flow path section 132, which have different depths and excellent processing accuracy, are formed inside the holding substrate 10 (plate-like member 11). This is because the depth D1 of the first horizontal flow path section 131 is deeper than the depth D2 of the second horizontal flow path section 132, and the first horizontal flow path section 131 is formed with a rod-shaped processing tool 91 having a rounded tip 91a, and the second horizontal flow path section 132 is formed with a rod-shaped processing tool 92 having an angular tip 92a, so that the bottom surface 131a of the first horizontal flow path section 131 is arc-shaped and the bottom surface 132a of the second horizontal flow path section 132 is linear.

[0064] <Embodiment 2> Next, a first horizontal channel section 131A and a second horizontal channel section 132A formed in a holding substrate 10A included in a holding device according to a second embodiment will be described with reference to FIG. 11. FIG. 11 is an explanatory diagram schematically illustrating a cross section 110A of the first horizontal channel section 131A and the second horizontal channel section 132A according to the second embodiment, cut in the thickness direction of the holding substrate 10A. In this embodiment, as in the first embodiment, the depth D1 of the first horizontal channel section 131A is greater than the depth D2 of the second horizontal channel section 132A. The bottom surface 131Aa of the first horizontal channel section 131A has an elliptical arc shape that bulges toward the second surface S2 (the lower side of FIG. 11), and the bottom surface 132Aa of the second horizontal channel section 132A has a linear shape.

[0065] The depth D1 of the first horizontal flow path section 131A is the length (maximum length) from the ceiling surface 131Ab to the bottom surface 131Aa of the first horizontal flow path section 131A. The depth D2 of the second horizontal flow path section 132A is the length (maximum length) from the ceiling surface 132Ab to the bottom surface 132Aa of the second horizontal flow path section 132A.

[0066] In this embodiment, when viewed in plan from the first surface S1 side, the width L2 of the second horizontal flow path section 132A is larger than the width L1 of the first horizontal flow path section 131A. As in the first embodiment, when viewed in plan from the first surface S1 side (upper side in FIG. 11), the width L1 of the first horizontal flow path section 131A is the length of the first horizontal flow path section 131A in a direction perpendicular to the longitudinal direction, where the direction in which the first horizontal flow path section 131A extends is the longitudinal direction. Furthermore, the width L2 of the second horizontal flow path section 132A is the length of the second horizontal flow path section 132A in a direction perpendicular to the longitudinal direction, where the direction in which the second horizontal flow path section 132A extends is the longitudinal direction, where ...

[0067] As in this embodiment, the bottom surface 131Aa of the first horizontal flow path section 131A may have an elliptical arc shape on the cross section 110A. Furthermore, on the cross section 110A, both ends of the bottom surface 132Aa of the second horizontal flow path section 132A may be rounded.

[0068] As described above, in the holding device of this embodiment, the first horizontal flow path section 131A and the second horizontal flow path section 132A, which have different depths and excellent processing accuracy, are formed inside the holding substrate 10A (plate-like member 11A). This is because the depth D1 of the first horizontal flow path section 131A is deeper than the depth D2 of the second horizontal flow path section 132A, and the first horizontal flow path section 131A is formed with a rod-shaped processing tool including a rounded tip, and the second horizontal flow path section 132 is formed with a rod-shaped processing tool with an angular tip, so that the bottom surface 131Aa of the first horizontal flow path section 131A is elliptical arc-shaped and the bottom surface 132Aa of the second horizontal flow path section 132A is linear.

[0069] <Embodiment 3> Next, a first horizontal flow path section 131B and a second horizontal flow path section 132B formed in a holding substrate included in a holding device according to embodiment 3 will be described with reference to Fig. 12. Fig. 12 is an explanatory diagram showing the first horizontal flow path section 131B and the second horizontal flow path section 132B formed in a plate-like member of the holding substrate according to embodiment 3, as seen perspectively from the first surface S1 side. In the above-described first and second embodiments, the first horizontal flow path section and the second horizontal flow path section constitute inert gas supply paths of separate systems that are not connected to each other, but the first horizontal flow path section 131B and the second horizontal flow path section 132B in this embodiment are connected to each other and communicate with each other.

[0070] As shown in FIG. 12 , the first horizontal flow path section 131B includes an outer first horizontal flow path section 131B1 having a large-diameter annular shape in plan view and a first horizontal flow path section 131B2 having a small-diameter annular shape disposed inside the first horizontal flow path section 131B1. In this embodiment, the outer first horizontal flow path section 131B1 and the inner first horizontal flow path section 131B2 are concentrically arranged. A plurality of second horizontal flow path sections 132B are provided to connect the first horizontal flow path section 131B and the first horizontal flow path section 131B2 to each other. Furthermore, as shown in FIG. 12 , a set of second horizontal flow path sections 132B is provided inside the inner annular first horizontal flow path section 131B2 to connect the first horizontal flow path sections 131B2 to each other. The pair of second horizontal flow path sections 132B are arranged so as to intersect with each other inside the first horizontal flow path section 131B2.

[0071] The first horizontal flow path section 131B and the second horizontal flow path section 132B are appropriately disposed at predetermined positions on the plate-like member depending on the flow rate of the inert gas to be passed through the inside thereof.

[0072] In this embodiment, the first vertical flow path section 120B is provided so as to overlap in plan view with the second horizontal flow path section 132B that connects the outer first horizontal flow path section 131B1 and the inner first horizontal flow path section 131B2. The first vertical flow path section 120B is connected to and communicates with the second horizontal flow path section 132B, and the inert gas supplied from the first horizontal flow path section 131B1 or the first horizontal flow path section 131B2 passes through the first vertical flow path section 120B and is discharged from a gas outlet.

[0073] In this embodiment, as in Embodiment 1, the depth of the first horizontal flow path section 131B (131B1, 131B2) is formed to be deeper than the depth of the second horizontal flow path section 132B. The bottom surface of the first horizontal flow path section 131B (131B1, 131B2) has a circular shape that bulges toward the second surface side (toward the back of the paper in FIG. 12) in a cross section cut in the thickness direction of the holding substrate, while the bottom surface of the second horizontal flow path section 132B is flat and linear in a cross section cut in the thickness direction of the holding substrate.

[0074] As in the first embodiment, the width of the second horizontal flow path section 132B is greater than the width of the first horizontal flow path section 131B (131B1, 131B2) when viewed in plan from the first surface side. The width of the second horizontal flow path section 132B is the length of the second horizontal flow path section 132B in a direction perpendicular to the longitudinal direction when the direction in which the second horizontal flow path section 132B extends when viewed in plan from the first surface side is defined as the longitudinal direction.

[0075] As described above, the first horizontal flow path section 131B and the second horizontal flow path section 132B, which are different in depth from each other, may be connected to each other so as to communicate with each other.

[0076] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention.

[0077] (1) As shown in Fig. 13, in another embodiment, the first horizontal flow path section 131C and the second horizontal flow path section 132C may be provided at different heights on a cut surface 110C cut in the thickness direction of the holding substrate 10C. Fig. 13 shows a state in which the first horizontal flow path section 131C is located higher (closer to the first surface) than the second horizontal flow path section 132C. In another embodiment, the second horizontal flow path section may be provided higher than the first horizontal flow path section.

[0078] (2) The gas flow path for passing the inert gas does not have to be formed in the base member, but may be formed only in the holding substrate.

[0079] (3) The manufacturing method of the holding device shown in the above embodiment is merely an example, and other manufacturing methods may be used as long as they do not impair the object of the present invention.

[0080] (4) Here, a holding device 100D according to Reference Example 1 will be described with reference to FIG. 14. FIG. 14 is a cross-sectional view schematically illustrating the internal structure of the holding device 100D according to Reference Example 1. The basic configuration of the holding device 100D is similar to that of the above-described first embodiment, and includes a holding substrate 10D and a base member 20D, which are bonded together with a bonding material 30D. The holding substrate 10D includes a ceramic plate-shaped member 11D and a substrate-side gas flow path 12D formed therein. The upper surface of the plate-shaped member 11D constitutes a first surface SD1 of the holding substrate 10D, and the lower surface of the plate-shaped member 11D constitutes a second surface SD2 of the holding substrate 10D. The substrate-side gas flow path 12D includes a first horizontal flow path portion 131D and a second horizontal flow path portion 132D as horizontal flow path portions 130D. The horizontal flow path section 130D of this reference example is provided on the lower surface (second surface SD2) of the holding substrate 10D (plate-like member 11D). In a cross section obtained by cutting the first horizontal flow path section 131D and the second horizontal flow path section 132D in the thickness direction of the holding substrate 10D, the depth of the first horizontal flow path section 131D is deeper than the depth of the second horizontal flow path section 132D, the ceiling surface of the first horizontal flow path section 131D has an arc-like or elliptical arc-like shape that bulges toward the second surface SD1, and the ceiling surface of the second horizontal flow path section 132D has a linear shape. Furthermore, when viewed from the first surface SD1 side (or the second surface SD2 side), the width of the second horizontal flow path section 132D is greater than the width of the first horizontal flow path section 131D. A base-side gas flow path 22D is formed in the base member 20D, and a bonding-side gas flow path 31D is formed in the bonding material 30D. As in this reference example, the shapes of the first and second horizontal flow path sections of the first embodiment and the like may be applied to the horizontal flow path section 130D (first horizontal flow path section 131D, second horizontal flow path section 132D) provided on the lower surface (second surface SD2) of the holding substrate 10D (plate-like member 11D) with the ceiling surface and bottom surface reversed upside down. The bottom surface of the second horizontal flow path section 132D is made up of a part of the bonding material 30D. The bottom surface of the first horizontal flow path section 131D is also made up of a part of the bonding material 30D.

[0081] (5) Next, a holding device 100E according to Reference Example 2 will be described with reference to FIG. 15. FIG. 15 is a cross-sectional view schematically illustrating the internal structure of the holding device 100E according to Reference Example 2. The basic configuration of the holding device 100E is similar to that of the above-described first embodiment, and includes a holding substrate 10E and a base member 20E, which are bonded together with a bonding material 30E. The holding substrate 10E includes a ceramic plate-shaped member 11E and a substrate-side gas flow path 12E formed therein. The upper surface of the plate-shaped member 11E constitutes a first surface SE1 of the holding substrate 10E, and the lower surface of the plate-shaped member 11E constitutes a second surface SE2 of the holding substrate 10E. The base member 20E has a generally circular third surface SE3 disposed on the upper side and facing the second surface SE2 of the holding substrate 10E, and a generally circular fourth surface SE4 disposed on the opposite side (i.e., the lower side) of the third surface SE3. The base member 20E has a base-side gas flow path 22E, and the bonding member 30E has a bonding-side gas flow path 31E. The base-side gas flow path 22E includes a first horizontal flow path portion 231E and a second horizontal flow path portion 232E as horizontal flow path portions 230E. In this reference example, the horizontal flow path portions 230E (the first horizontal flow path portion 231E and the second horizontal flow path portion 232E) are provided on the upper surface (third surface SE3) of the base member 20E. In cross sections obtained by cutting the first horizontal flow path portion 231E and the second horizontal flow path portion 232E in the thickness direction of the base member 20E, the depth of the first horizontal flow path portion 231E is deeper than the depth of the second horizontal flow path portion 232E, the bottom surface of the first horizontal flow path portion 231E has an arc-like or elliptical arc-like shape that bulges toward the fourth surface SE2, and the bottom surface of the second horizontal flow path portion 232E has a linear shape. Furthermore, in a plan view from the third surface SE3 side, the width of the second horizontal flow path section 232E is larger than the width of the first horizontal flow path section 231E. As in the first embodiment and the like, the first horizontal flow path section 231E and the second horizontal flow path section 232E, each having a predetermined bottom shape, width, and the like, may be applied to the horizontal flow path section 230E provided on the upper surface (third surface SE3) of the base member 20E as in this reference example. Note that the ceiling surface of the second horizontal flow path section 232E is made of a part of the bonding material 30E. Similarly, the ceiling surface of the first horizontal flow path section 231E is also made of a part of the bonding material 30E. [Explanation of symbols]

[0082] 100...holding device, 110...cut surface of holding substrate, 10...holding substrate, 11...plate-shaped member, 12...substrate-side gas flow path (gas flow path), 12a...gas inlet, 12b...gas outlet, 120...first vertical flow path section, 130...horizontal flow path section, 131...first horizontal flow path section, 131a...bottom surface of first horizontal flow path section, 132...second horizontal flow path section, 132a...bottom surface of second horizontal flow path section, 140...second vertical flow path section, 70...porous body, D1...depth D1 of first horizontal flow path section, D2...depth D2 of second horizontal flow path section, S1...first surface, S2...second surface, W...wafer (object)

Claims

1. A holding device including a holding substrate having a plate-like member including a first surface and a second surface disposed on an opposite side of the first surface, and a gas flow path formed inside the plate-like member, the gas flow path including a gas outlet opening on the first surface side and a gas inlet opening on the second surface side, the gas flow path has a first lateral flow path portion and a second lateral flow path portion extending parallel to the first surface, In a cut surface obtained by cutting each of the first horizontal flow path section and the second horizontal flow path section in a thickness direction of the holding substrate, a depth of the first horizontal flow path section is greater than a depth of the second horizontal flow path section, and a bottom surface of the first horizontal flow path section has an arc shape or an elliptical arc shape that bulges toward the second surface side, The bottom surface of the second horizontal flow path portion is a linear holding device.

2. The holding device according to claim 1 , wherein, in a plan view from the first surface side, the width of the second horizontal flow path portion is larger than the width of the first horizontal flow path portion.

3. The holding device according to claim 1 or 2, wherein the first horizontal flow path section and the second horizontal flow path section are connected to each other and communicate with each other.

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