Holding device

Abstract

According to the present invention, there is provided a holding device including a holding substrate having a plurality of lateral flow passage portions each having a different depth and excellent processing accuracy. [Solution] A holding device 100 of the present invention includes a holding substrate 10 having a plate-like member 11 including a first surface S1 and a second surface S2, and a gas flow path 12 including a gas outlet 12b opening on the first surface S1 side and a gas inlet 12a opening on the second surface S2 side and formed inside the plate-like member 11. The gas flow path 12 has a first horizontal flow path section 131 and a second horizontal flow path section 132 extending parallel to the first surface S1, and 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, a depth D1 of the first horizontal flow path section 131 is deeper than a depth D2 of the second horizontal flow path section 132, a bottom surface 131a of the first horizontal flow path section 131 has a circular or elliptical arc shape that bulges toward the second surface S2 side, and a bottom surface 132a of the second horizontal flow path section 132 has a straight line shape.

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) mainly made 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, in plasma processing such as plasma etching, a thermally conductive gas such as helium gas is supplied between the holding substrate and the wafer 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 thermally conductive 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 a planar direction (i.e., a direction perpendicular to the thickness direction). As shown in Patent Document 2, the horizontal flow path portion in the holding substrate has a flat upper surface and an arc-shaped or elliptical bottom surface in a cross section cut in the thickness direction.

[0005] Conventionally, the bottom side of the horizontal flow passage parts provided inside the holding substrate was always processed to have the same shape (arc shape, etc.) regardless of the difference in the flow passage size (flow passage width, depth, etc.) This is because, when forming the gas flow passages (horizontal flow passage parts, 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] Patent Publication No. 2022-68650 Summary of the Invention [Problem to be solved by the invention]

[0007] There are cases where it is desired to appropriately adjust the flow rate of the thermally conductive gas flowing inside the horizontal flow passage portion depending on the location where the horizontal flow passage portion is formed. For example, in the case of a horizontal flow passage portion provided in a location of the holding substrate where heat is likely to accumulate, it is desired to make the depth deeper than other horizontal flow passage portions. Horizontal flow passage portions that require such depth have been formed into an arc shape with a large bulge on the bottom side using a processing tool with a rounded tip. However, if an attempt is made to form a horizontal flow passage portion with a shallow depth, for example, using a processing tool suitable for a horizontal flow passage portion with a large depth, the processing accuracy of the horizontal flow passage portion with a shallow depth will deteriorate.

[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 machined 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 an opposite side to 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 horizontal flow path section and a second horizontal flow path section extending parallel to the first surface, the first horizontal flow path section has a depth greater than a depth of the second horizontal flow path section on a cut surface obtained by cutting the first horizontal flow path section and the second horizontal flow path section in a thickness direction of the holding substrate, and the first horizontal flow path section has a bottom surface that forms a circular or 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 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. <1> A holding device as described in

[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> A holding device as described in Effect 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 accuracy. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view showing a schematic external configuration of a holding device according to a first embodiment; [Diagram 2] FIG. 1 is a cross-sectional view showing a schematic internal structure of a holding device according to a first embodiment; [Diagram 3] FIG. 1 is an explanatory diagram showing a first lateral flow path section and a second lateral flow path section formed in a plate-like member of a holding substrate, as seen through a plan view from a first surface side; [Figure 4] FIG. 1 is an explanatory diagram showing a schematic cross section of a first horizontal flow path section and a second horizontal flow path section cut in the thickness direction of a holding substrate; [Diagram 5] FIG. 1 is a schematic diagram illustrating a method for manufacturing a holding substrate; [Figure 6] FIG. 1 is a schematic diagram illustrating a method for manufacturing a holding substrate; [Figure 7] FIG. 1 is an explanatory diagram showing a schematic diagram of 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 in the laminate of green sheets; [Figure 8] FIG. 1 is a schematic diagram illustrating a state in which a groove for a first transverse flow path portion and a groove for a second transverse flow path portion are formed in a laminate of green sheets; [Figure 9]FIG. 1 is a schematic diagram illustrating a state in which a groove for a first transverse flow path portion and a groove for a second transverse flow path portion formed in a laminate of green sheets are filled with a filler material. [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] FIG. 11 is an explanatory diagram showing a schematic 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. 11 is an explanatory view showing 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, as seen through the first surface side in a planar view; [Figure 13] FIG. 11 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. 1 is a cross-sectional view showing a schematic internal structure of a holding device according to a first embodiment; [Figure 15] FIG. 11 is a cross-sectional view showing a schematic internal structure of a holding device according to a second embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <Embodiment 1> A holding device 100 according to a first embodiment will be described below with reference to Fig. 1 to Fig. 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 in a process of performing etching using plasma in a reduced pressure chamber, for example.

[0015] Fig. 1 is a perspective view showing a schematic external configuration of a holding device 100 according to the first embodiment, and Fig. 2 is a cross-sectional view showing a schematic 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 larger than the holding substrate 10. For example, when 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 a disk-shaped with a diameter of 340 mm and a thickness of 20 mm. The holding substrate 10 and the base member 20 may each be provided with a positioning portion (such as a projection or recess) for mutual alignment.

[0016] The holding substrate 10 and the base member 20 are stacked on top of each 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 spread out in a layered state.

[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-like member 11 is a plate-like (disk-like) insulating member whose main component is ceramic. In this specification, the term "main component" means the component with the highest content (e.g., a content of 50 volume % or more). The plate-like member 11 in this embodiment is made of alumina (Al2O3). In other embodiments, the plate-like member 11 may be made of other ceramics such as aluminum nitride (AlN).

[0020] The substrate-side gas flow passage (an example of a gas flow passage) 12 constitutes a part of a flow passage 60 for flowing an inert gas (for example, helium gas, which is a thermally conductive gas) provided in the holding device 100. The substrate-side gas flow passage 12 is formed inside the plate-like member 11 of the holding substrate 10. The substrate-side gas flow passage 12 is made of holes penetrating the holding substrate 10, including a gas inlet 12a opening on the second surface S2 of the holding substrate 10 and a gas outlet 12b opening on 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 passage 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 flow outlet 12b that opens on the first surface S1 side, and is a flow path extending from the gas flow 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. The horizontal flow path section 130 includes a first horizontal flow path section 131 and a second horizontal flow path section 132, as described later.

[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, which is filled in the first vertical flow passage section 120, which is a part of the substrate-side gas flow passage 12, and is mainly composed of ceramics. The porous body 70 is a gas-permeable member mainly composed of insulating ceramics and containing a large number of pores. The porous body 70 is filled in each of the first vertical flow passage sections 120 in the substrate-side gas flow passage 12. The porous body 70 is generally cylindrical and extends in the vertical direction (thickness direction of the holding substrate 10), and a ventilation path for passing an inert gas is formed in the inside in a mesh-like shape. The ventilation path is composed of a large number of pores connected to each other in the porous body 70. The pores are formed as traces of a particulate pore-forming material burned (disappeared) during the manufacture (firing) of the porous body 70. For example, synthetic resin beads, carbon powder, etc. are used as the pore-forming material.

[0026] The porous body 70 is filled in the first vertical flow path section 120 so that a space is formed below the porous body 70. The upper end surface 70a of the porous body 70 is circular and exposed from the gas outlet 12b. The space is formed on the downstream side of the horizontal flow path section 130. In the case of 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 to each other by sintering. The lower end surface of the porous body 70 faces the space in 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 generally parallel to the first surface S1. The chuck electrode 40 is made of a conductive material such as tungsten, molybdenum, platinum, or the like. As shown in FIG. 2, the chuck electrode 40 is disposed on the first surface S1 side inside the holding substrate 10 (plate-like member 11). The chuck electrode 40 is connected to an external power source via a terminal or the like. When power is supplied to the chuck electrode 40, an electrostatic attraction is generated, and the wafer W is attracted and held on the first surface S1 of the holding substrate 10 by the electrostatic attraction. In other embodiments, a high-frequency electrode or a heater electrode may be provided as the electrode member.

[0028] 1 and 2, a first surface S1 of the holding substrate 10 is provided with a plurality of gas outlets 12b. The outer peripheral edge of the first surface S1 is formed in an annular shape and protrudes slightly upward compared to the inner portion thereof. Therefore, when the 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. Note that a plurality of convex portions (mesas) (not shown) are formed on the first surface S1.

[0029] The base member 20 is mainly composed 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 to cool the plasma heat. When the coolant is caused to flow through the coolant flow path 21, the base member 20 is cooled, and the holding substrate 10 is cooled by heat transfer (heat withdrawal) 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 passage 22 constituting a part of the flow passage 60 is provided inside the base member 20. The base-side gas flow passage 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 opening on the fourth surface S4 of the base member 20 and an outlet 22b opening on the third surface S3. The inlet 22a serves as an inlet for the base-side gas flow passage 22, and also serves as an inlet for the entire flow passage 60 provided in the holding device 100.

[0032] The bonding material 30 is composed 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 is preferably one that 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 a part of the flow passage 60. The bonding-side gas flow passage 31 is formed of a hole that penetrates the layered bonding material 30 in the thickness direction.

[0034] The flow path 60 supplies an inert gas (helium gas, etc.) 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, such a 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 passage 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 passes through the base-side gas passage 22, the bonding-side gas passage 31, and the substrate-side gas passage (gas passage) 12 connected to each inlet 22a in this order, 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 a lower (base member 20 side) opening of the bonding-side gas flow passage 31. In addition, an upper (holding substrate 10 side) opening 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 inlets 12a of the substrate-side gas flow passage (gas flow passage) 12 are provided on the second surface S2 of the holding substrate 10.

[0037] The second vertical flow path section 140 including 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 the downstream side. The first vertical flow path section 120 is connected to each horizontal flow path section 130. 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] Here, 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 with reference to Fig. 3 and Fig. 4. 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 in a see-through plan view from the first surface S1 side, and Fig. 4 is an explanatory diagram showing a schematic representation of a cut surface 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. In 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, such that 0.2 < D1 ≤ 1.3, and the depth D2 (mm) of the second cross-flow path portion 132 is set, for example, such that 0 < D2 ≤ 0.2.

[0041] And, in the cut surface 110, the bottom surface 131a of the first cross-flow path portion 131 forms an arc shape that bulges toward the second surface S2 side (the lower side in FIG. 4). Note that in other embodiments, the bottom surface of the first cross-flow path portion 131 may form 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 forms a straight line 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, such that 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, such that 5.2 ≤ L2 ≤ 6.2.

[0044] The first cross-flow path portion 131 is formed using a machining tool with a rounded tip, as will be described later. In contrast, the second cross-flow path portion 132 is formed using a machining 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 provided to be at substantially the same height on the cut surface 110. In the present 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 provided to be substantially the same. Note that in other embodiments, the height position of the bottom surface 131a (the lowermost portion) 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 provided to be substantially the same.

[0046] Next, an example of a manufacturing method of the holding device 100 of this embodiment will be described. First, a manufacturing method of 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 diagrammatically show a manufacturing method of the holding substrate 10. This manufacturing method of 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 member 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 another green sheet.

[0048] The slurry for the green sheets is obtained by, for example, mixing a mixture containing alumina powder, an acrylic binder, a dispersant, a plasticizer, etc., with an organic solvent added thereto, using a ball mill. This slurry is formed into a sheet shape 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 is obtained by, for example, 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, for example, using a screen printing device, to form the conductor layer 9 on a specific green sheet.

[0050] 5(B), holes 81 for forming the first vertical flow path portions 120 are formed at predetermined locations of the first laminate 80a. The holes 81 are provided in a cylindrical shape penetrating the first laminate 80a in the thickness direction. The holes 81 are formed at 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 paste 7 for a porous body for forming a porous body 70. The paste 7 for a porous body is obtained by kneading a mixture containing, for example, alumina powder, a pore former, a binder, an organic solvent, and the like. Methods for filling the paste 7 for a porous body into the holes 81 include, for example, a method using an injection molding device, a method using a screen printing device, and the like. The first laminate 80a in which the paste 7 for a porous body has been filled into the holes 81 is dried as appropriate.

[0052] Then, as shown in Fig. 6(D), the first laminate 80a and the second laminate 80b are laminated. The second laminate 80b is made of a plurality of green sheets laminated together. In addition, holes 82 for forming the second vertical flow path section 140 and grooves 83 for forming the horizontal flow path section 130 are provided at predetermined positions of the second laminate 80b.

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

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

[0055] The processing tool 91 is for forming the grooves 183 for the first horizontal passage section 131 in the green sheet laminate 80b1, and has a rod shape with a rounded tip 91a. The processing tool 91 is suitable for forming a passage with a relatively large depth. In contrast, the processing tool 92 is for forming the grooves 283 for the second horizontal passage section 132 in the green sheet laminate 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 a passage with a relatively small depth (shallow). In FIG. 7, the area where the grooves 183 for the first horizontal passage section 131 are to be formed is indicated by a broken line below the processing tool 91, and the area where the grooves 283 for the second horizontal passage section 132 are to be formed is indicated by a broken line below the processing tool 92.

[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-rear direction of the paper).

[0057] FIG. 8 is an explanatory diagram that shows 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 has a groove 183 for the first horizontal flow path section 131 and a groove 283 for the second horizontal flow path section 132 formed therein. The groove 183 is formed by scraping the surface of the laminate 80b1 with a rounded tip 91a of a processing tool 91, and the bottom surface 183a of the groove 183 is arc-shaped so as to bulge downward. The groove 283 is formed by scraping the surface of the laminate 80b1 with a corner-shaped tip 92a of a processing tool 92, and the bottom surface 283a of the groove 283 is linear.

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

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

[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, for example, a laminate of 20 green sheets, which are thermocompression bonded together. The outer periphery of the laminate may be appropriately cut. Then, the laminate is cut by machining to produce a disk-shaped molded body. The obtained molded body is then degreased and fired, and the molded body after degreased and fired is further fired (main firing) to obtain a fired body.

[0061] Then, a mask is placed on the surface of the sintered body to cover the portion corresponding to the convex outer periphery, and a convex outer periphery is formed on the surface of the sintered body by, for example, shot blasting, which projects particles of ceramics, etc. Then, the surface of the sintered body is polished, etc., 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 produced, they are bonded using a bonding material 30. The bonding of the holding substrate 10 and the base member 20 by 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 manner, 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 made deeper than the depth D2 of the second horizontal flow path section 132, and the first horizontal flow path section 131 is formed by a rod-shaped processing tool 91 having a rounded tip 91a, and the second horizontal flow path section 132 is formed by 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, the first horizontal channel section 131A and the second horizontal channel section 132A formed in the holding substrate 10A included in the holding device according to the second embodiment will be described with reference to FIG. 11. FIG. 11 is an explanatory diagram that shows a schematic cross section 110A obtained by cutting the first horizontal channel section 131A and the second horizontal channel section 132A according to the second embodiment in the thickness direction of the holding substrate 10A. In the present embodiment, as in the first embodiment, the depth D1 of the first horizontal channel section 131A is formed to be deeper than the depth D2 of the second horizontal channel section 132A. In addition, the bottom surface 131Aa of the first horizontal channel section 131A is formed in an elliptical arc shape that bulges toward the second surface S2 side (the lower side of FIG. 11), and the bottom surface 132Aa of the second horizontal channel section 132A is formed in a straight line.

[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, 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 when viewed from the first surface S1 side. As in the first embodiment, 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 when the direction in which the first horizontal flow path section 131A extends is taken as the longitudinal direction when viewed from the first surface S1 side (upper side in FIG. 11), and 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 when the direction in which the second horizontal flow path section 132A extends is taken as the longitudinal direction when viewed from the first surface S1 side.

[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 cut surface 110A. Furthermore, on the cut surface 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 made 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 processing tool equipped with a rod-shaped tip with an angular shape, 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, the first horizontal flow path section 131B and the second horizontal flow path section 132B formed in the holding substrate included in the holding device according to the third embodiment 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 the plate-like member of the holding substrate according to the third embodiment, as seen through in a plan view from the first surface S1 side. In the first and second embodiments described above, the first horizontal flow path section and the second horizontal flow path section constitute supply paths for inert gas 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 a plan view, and a small diameter annular first horizontal flow path section 131B2 arranged inside the first horizontal flow path section 131B1. In the present embodiment, the outer first horizontal flow path section 131B1 and the inner first horizontal flow path section 131B2 are arranged concentrically. A plurality of second horizontal flow path sections 132B are provided so as to connect the first horizontal flow path section 131B and the first horizontal flow path section 131B2 to each other. In addition, as shown in FIG. 12, a set of second horizontal flow path sections 132B connecting the first horizontal flow path sections 131B2 to each other is also provided inside the first horizontal flow path section 131B2 arranged inside and having an annular shape. The pair of second horizontal flow path portions 132B are disposed so as to intersect with each other inside the first horizontal flow path portion 131B2.

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

[0072] In this embodiment, the first vertical flow path section 120B is provided so as to overlap in a 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 (the back side of the paper in FIG. 12) in a cross section cut in the thickness direction of the holding substrate, and 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] Similarly to the first embodiment, the width of the second horizontal flow path section 132B is larger 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 is defined as the longitudinal direction when viewed in plan from the first surface side.

[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 channel section 131C and the second horizontal channel section 132C may be provided at different height positions 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 channel section 131C is located higher (on the first surface side) than the second horizontal channel section 132C. In another embodiment, the second horizontal channel section may be provided to be located higher than the first horizontal channel section.

[0078] (2) The gas flow passage for passing the inert gas does not have to be formed in the base member, and 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 that shows a schematic internal structure of the holding device 100D according to Reference Example 1. The basic configuration of the holding device 100D is the same as that of the above-mentioned embodiment 1, and includes a holding substrate 10D and a base member 20D, which are bonded by 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 is the first surface SD1 of the holding substrate 10D, and the lower surface of the plate-shaped member 11D is the 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 a horizontal flow path portion 130D. The horizontal flow passage 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 cut surface obtained by cutting the first horizontal flow passage section 131D and the second horizontal flow passage section 132D in the thickness direction of the holding substrate 10D, the depth of the first horizontal flow passage section 131D is deeper than the depth of the second horizontal flow passage section 132D, the ceiling surface of the first horizontal flow passage section 131D is in the shape of a circular arc or an elliptical arc bulging toward the second surface SD1, and the ceiling surface of the second horizontal flow passage section 132D is in the shape of a straight line. In addition, when viewed in a plan view from the first surface SD1 side (or the second surface SD2 side), the width of the second horizontal flow passage section 132D is larger than the width of the first horizontal flow passage section 131D. Note that a base-side gas flow passage 22D is formed in the base member 20D, and a joint-side gas flow passage 31D is formed in the joint material 30D. As in this reference example, the shapes of the first and second horizontal flow path sections in the above-mentioned embodiment 1 and the like may be applied to a 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 a holding substrate 10D (plate-like member 11D) in a state in which the ceiling surface side and the bottom surface side are inverted upside down. The bottom surface of the second horizontal flow path section 132D is made of a part of the bonding material 30D. The bottom surface of the first horizontal flow path section 131D is also made 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 that shows a schematic internal structure of a holding device 100E according to Reference Example 2. The basic configuration of the holding device 100E is the same as that of the above-mentioned embodiment 1, and includes a holding substrate 10E and a base member 20E, which are bonded by 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 is the first surface SE1 of the holding substrate 10E, and the lower surface of the plate-shaped member 11E is the second surface SE2 of the holding substrate 10E. The base member 20E has a substantially circular third surface SE3 that is disposed on the upper side and faces the second surface SE2 of the holding substrate 10E, and a substantially circular fourth surface SE4 that is 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 passage 22E, and the bonding member 30E has a bonding-side gas flow passage 31E. The base-side gas flow passage 22E includes a first horizontal flow passage portion 231E and a second horizontal flow passage portion 232E as the horizontal flow passage portion 230E. The horizontal flow passage portion 230E (the first horizontal flow passage portion 231E and the second horizontal flow passage portion 232E) of this reference example is provided on the upper surface (the third surface SE3) of the base member 20E. In a cut surface obtained by cutting the first horizontal flow passage portion 231E and the second horizontal flow passage portion 232E in the thickness direction of the base member 20E, the depth of the first horizontal flow passage portion 231E is deeper than the depth of the second horizontal flow passage portion 232E, the bottom surface of the first horizontal flow passage portion 231E has a circular or elliptical arc shape that bulges toward the fourth surface SE2, and the bottom surface of the second horizontal flow passage portion 232E has a straight line shape. In addition, when viewed 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 present reference example, the first horizontal flow path section 231E and the second horizontal flow path section 232E each having a predetermined bottom shape, width, etc. 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 the above-mentioned embodiment 1, etc. Note that the ceiling surface of the second horizontal flow path section 232E is made of a part of the bonding material 30E. 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 to 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 includes a first lateral flow path portion extending parallel to the first surface and a second lateral flow path portion; a depth of the first horizontal flow path portion is greater than a depth of the second horizontal flow path portion in a cut surface obtained by cutting the first horizontal flow path portion and the second horizontal flow path portion in a thickness direction of the holding substrate, and a bottom surface of the first horizontal flow path portion has an arc shape or an elliptical arc shape that bulges toward the second surface side, The bottom surface of the second horizontal flow passage portion is a linear holding device.

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

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

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