Holding device

Abstract

To provide a retainer comprising a holding substrate in which a gas flow channel is filled with a porous body with a good gas permeability.SOLUTION: A retainer 100 of the present invention, comprises: a plate-like member 11 that includes a first front surface S1 holding an object W and a second front surface S2 arranged to the opposite side, and contains ceramic as a main component; a gas flow channel 12 formed in the inner part; and a gas permeable porous body 70 which part of the gas flow channel 12 is filled with and contains ceramic as a main component. The gas flow channel 12 includes: a vertical flow channel part 120 that includes a gas outflow port 12b opened to the first front surface S1 side, and is extended to the second front surface S2 side from the gas outflow port 12b; and a lateral flow channel part 130 that is connected to the vertical flow channel part 120, and is extended in parallel with the first front surface S1. The vertical flow channel part 120 is filled with the porous body 70 so that a space V is formed in the lateral flow channel part 130 on the second front surface S2 side.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] An electrostatic chuck is an example of a holding device that holds a wafer (semiconductor wafer) when manufacturing a semiconductor (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] In addition, the high frequency power applied during plasma processing can cause abnormal discharge (arcing) in the gas flow passage, which can damage the wafer on the holding substrate. Therefore, in order to suppress the occurrence of such abnormal discharge, a gas-permeable porous body made of an insulating ceramic material is provided inside the gas flow passage. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4959905 Summary of the Invention [Problem to be solved by the invention]

[0006] In the case of conventional holding devices, the contact area between the gas (inert gas such as thermally conductive gas) supplied through the gas flow path and the surface of the porous body is small, and the pressure loss of the gas in the porous body is large. Therefore, the amount of gas that can permeate the porous body is smaller than the amount of gas supplied to the gas flow path from the outside.

[0007] An object of the present invention is to provide a holding device including a holding substrate having a gas flow passage filled with a porous material having excellent gas permeability. [Means for solving the problem]

[0008] The means for solving the above problems are as follows. <1> A holding device comprising a holding substrate having a plate-shaped member mainly composed of ceramics, the plate-shaped member including a first surface for holding an object and a second surface disposed opposite the first surface, a gas flow path formed inside the plate-shaped member, and a gas-permeable porous body mainly composed of ceramics filled in a portion of the gas flow path, the gas flow path including a gas outlet opening on the first surface side, a vertical flow path section extending from the gas outlet to the second surface side, and a horizontal flow path section connected to the vertical flow path section and extending parallel to the first surface, the porous body being filled in the vertical flow path section such that a space is formed in the horizontal flow path section on the second surface side of the porous body.

[0009] <2> The porous body has an end face on the second surface side facing the space, and has a convex end face that is raised on the second surface side. <1> A holding device as described in

[0010] <3> The porous body has an end face on the second surface side facing the space, and a concave end face recessed on the first surface side. <1> A holding device as described in

[0011] <4> the horizontal flow path portion includes a bottom surface facing the porous body, and the porous body has a main body portion filled in the vertical flow path portion, and a support portion extending from the main body portion to the bottom surface such that the space is formed on the second surface side of the main body portion and the main body portion is supported on the bottom surface. <1> A holding device as described in

[0012] <5> the porous body is disposed closer to the second surface than the gas outlet and has a wide portion that is wider than the gas outlet in a radial direction; <1> ~ <4> 13. A holding device according to any one of the preceding claims.

[0013] <6> The space is provided at one end of the horizontal flow path. <1> ~ <5> 13. A holding device according to any one of the preceding claims. Effect of the Invention

[0014] According to the present invention, it is possible to provide a holding device including a holding substrate in which a gas flow path is filled with a porous material having excellent gas permeability. [Brief description of the drawings]

[0015] [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] Cross-sectional view of the holding substrate with a portion of the substrate-side gas flow path enlarged. [Figure 4] Cross section of line AA in Figure 3 [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. 11 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path of a holding substrate according to a second embodiment. [Figure 8] FIG. 11 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path of a holding substrate according to a third embodiment. [Figure 9] FIG. 13 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path of a holding substrate according to a fourth embodiment. [Figure 10] FIG. 13 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path of a holding substrate according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <Embodiment 1> A holding device 100 according to a first embodiment will be described below with reference to Fig. 1 to Fig. 6. 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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" means the component with the largest content. The plate-shaped member 11 in this embodiment is made of alumina (Al2O3). In other embodiments, the plate-shaped member 11 may be made of other ceramics such as aluminum nitride (AlN).

[0022] 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 an 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 the inert gas is supplied from the 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.

[0023] Fig. 3 is a cross-sectional view of the holding substrate 10 in which a part of the substrate-side gas flow path 12 is enlarged, and Fig. 4 is a cross-sectional view taken along the line AA in Fig. 3. Fig. 3 shows a cross-sectional structure obtained by cutting the holding substrate 10 along the thickness direction. As shown in Fig. 3 and other figures, the substrate-side gas flow path 12 includes a first vertical flow path portion 120, a horizontal flow path portion 130, and a second vertical flow path portion 140.

[0024] 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 extending 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 extending in the vertical direction, and an opening 12c, which is an inlet of the first vertical flow path section 120 and has substantially the same diameter as the gas outlet 12b, is provided on the opposite side of the gas outlet 12b. A porous body 70, which will be described later, is filled in such a first vertical flow path section 120. The first vertical flow path section 120 is composed of a section between the gas outlet 12b and the opening 12c in the substrate-side gas flow path 12.

[0025] The horizontal flow passage section 130 is a flow passage that is connected to the first vertical flow passage section 120 and extends parallel to the first surface S1. The downstream side of the horizontal flow passage section 130 is connected to an opening 12c on the upstream side of the first vertical flow passage section 120. In the substrate side gas flow passage 12, the inlet 12a side is the upstream side, and the gas outlet 12b is the downstream side.

[0026] The horizontal flow path section 130 comprises a bottom horizontal flow path section 131 including a bottom 131a that faces the porous body 70 filled in the first vertical flow path section 120, and a main body horizontal flow path section 132 that connects between the bottom horizontal flow path section 131 and the second vertical flow path section 140.

[0027] The bottom 131a of the bottom horizontal flow path section 131 has a substantially circular shape in a plan view and is set to be substantially the same size as the gas outlet 12b and the opening 12c. The surface (bottom surface) 131a1 of the bottom 131a is flat. The bottom horizontal flow path section 131 has a substantially cylindrical peripheral wall section 131b that rises from the periphery of the bottom 131a toward the first surface S1 side. The peripheral wall section 131c is provided with an opening 131c, and the opening 131c is connected to the downstream side of the main body horizontal flow path section 132. The bottom horizontal flow path section 131 forms a flat flow path that spreads parallel to the first surface S1.

[0028] The main body horizontal channel section 132 forms an elongated channel extending parallel to the first surface S1, the upstream side of which is connected to the second vertical channel section 140 and the downstream side of which is connected to the opening 131c of the bottom horizontal channel section 131.

[0029] The second vertical flow path section 140 includes an inlet 12a that opens to the second surface S2, and is a flow path extending from the inlet 12a to the first surface S1 side along the thickness direction of the plate-like member 11. 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 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 extending in the vertical direction.

[0030] The holding substrate 10 also includes a gas-permeable porous body 70, the main component of which is ceramic, which is filled in the first vertical flow path section 120, which is a part of the substrate-side gas flow path 12. The porous body 70 will be described in detail later.

[0031] 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 an electrically conductive material such as tungsten, molybdenum, or platinum. 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. The chuck electrode 40 includes a through hole 41 which penetrates in the thickness direction (vertical direction). In other embodiments, a high-frequency electrode or a heater electrode may be provided as the electrode member.

[0032] 1 and 2, a plurality of gas outlets 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 an annular shape and protrudes slightly upward compared to the inner portion thereof. Therefore, when the wafer W is attracted and held 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.

[0033] 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).

[0034] 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 flows 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. The temperature of the wafer W held on the first surface S1 can be controlled by appropriately adjusting the flow rate of the coolant through the coolant flow path 21.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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, the upper (holding substrate 10 side) opening of the bonding-side gas flow passage 31 is connected to an inlet 12a of the substrate-side gas flow passage (gas flow passage) 12. A plurality of 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.

[0041] The second vertical flow path section 140 including the 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 of the horizontal flow path sections 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).

[0042] Next, the porous body 70 and the substrate-side gas flow passage 12 filled with the porous body 70 will be described in detail.

[0043] The porous body 70 is a gas-permeable member containing a large number of pores, and is mainly composed of insulating ceramics. The porous body 70 is filled in each of the first vertical flow passage parts 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 particulate pore-forming material burned (disappeared) during the manufacturing (firing) of the porous body 70. For example, synthetic resin beads, carbon powder, etc. are used as the pore-forming material.

[0044] The porous body 70 is filled in the first vertical flow path section 120 so that a space V is formed below the porous body 70. The porous body 70 is filled in the cylindrical first vertical flow path section 120 so that the circular upper end surface 70a is exposed from the gas outlet 12b and the circular lower end surface 70b is exposed from the opening 12c to the space V. The space V is formed in the bottom horizontal flow path section 131 of the horizontal flow path section 130. That is, the horizontal flow path section 130 has the space V in the bottom horizontal flow path section 131 arranged at one end on the downstream side. The space V is surrounded by the lower end surface 70b of the porous body 70, the surface (bottom surface) 131a1 of the bottom 131a, and the surface of the peripheral wall section 131b. Such a porous body 70 is filled in the first vertical flow path section 120 so that a space V is formed on the second surface S2 side (i.e., the lower end surface 70b side) of the porous body 70 in the bottom horizontal flow path section 131 of the horizontal flow path section 130. As shown in FIG. 3, the porous body 70 is disposed on the second surface S2 side of the gas outlet 12b and on the first surface S1 side of the horizontal flow path section 130. In this embodiment, the first surface S1 and the upper end surface 70a are disposed so as to be flush with each other. The peripheral surface 70c of the porous body 70 is cylindrical and extends straight in the vertical direction. The porous body 70 and the peripheral wall portion 111 constituting the first vertical flow path section 120 are bonded to each other by sintering.

[0045] The lower end surface 70b of the porous body 70 faces the space V in the horizontal flow passage section 130 (bottom horizontal flow passage section 131), and the inert gas supplied from the upstream side of the substrate side gas flow passage (gas flow passage) 12 is supplied into the porous body 70 from this lower end surface 70b. The lower end surface 70b is porous, and the lower end surface 70b serves as an inlet for the inert gas. The lower end surface 70b of the porous body 70 is set to have an area approximately equal to that of the circular bottom portion 131a facing it. The bottom portion 131a of the bottom horizontal flow passage section 131 is provided at a position overlapping the lower end surface 70b (upper end surface 70b) of the porous body 70 in a plan view. As shown in FIG. 4, the bottom portion 131a of the bottom horizontal flow passage section 131 is set to be larger than the width of the main body horizontal flow passage section 132 of the horizontal flow passage section 130 in a plan view.

[0046] Such a lower end surface 70b has a large area (i.e., an area exposed to the space V) that comes into contact with the inert gas supplied from the upstream side by using the substrate-side gas flow path (gas flow path) 12. Therefore, compared with a conventional product in which there is no space below the porous body and a lateral flow path portion is connected to a part of the circumferential surface of the porous body, the holding device 100 of this embodiment can reduce the pressure loss of the gas in the porous body 70.

[0047] Next, an example of a manufacturing method of the holding device 100 of this embodiment will be described. Here, first, a manufacturing method of the holding substrate 10 constituting the holding device 100 will be described with reference to Figs. 5 and 6. Figs. 5 and 6 are explanatory diagrams that typically 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.).

[0052] 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.

[0053] Thereafter, 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, a hole 82 for forming the second vertical flow path portion 140 and a groove 83 for forming the horizontal flow path portion 130 are provided at predetermined positions of the second laminate 80b. The laminate made of the first laminate 80a and the second laminate 80b is made of, for example, a laminate of 20 green sheets, which are thermocompressed 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. Thereafter, the obtained molded body is degreased and fired, and further, the molded body after degreased and fired is fired (main firing) to obtain a fired body.

[0054] 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).

[0055] The above-mentioned degreasing and firing are performed by arranging the first laminate 80a and the second laminate 80b so that the first surface S1 side of the holding substrate 10 is on the upper side and the second surface S2 side is on the lower side. In such degreasing and firing, the paste 7 for porous body (unfired composition) filled in the holes 81 and the laminate of green sheets for forming the plate-like member 11 and the like are fired simultaneously.

[0056] The method of manufacturing the base member 20 is basically the same as that of the conventional product, and therefore a detailed description thereof will be omitted.

[0057] After the holding substrate 10 and the base member 20 are produced, 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 that in the conventional products. Therefore, a detailed description thereof will be omitted. In this manner, the holding device 100 is manufactured.

[0058] As described above, in the holding device 100 of this embodiment, a space V is provided in the horizontal flow path section 130 at the lower end surface 70b of the porous body 70 filled in the first vertical flow path section (an example of a vertical flow path section) 120 of the substrate side gas flow path (an example of a gas flow path) 12. There is a space V (gap) between the lower end surface 70b of the porous body 70 and the bottom 131a of the bottom horizontal flow path section 131 facing it, and the entire lower end surface 70b facing this space V functions as an inlet for supplying inert gas to the inside of the porous body 70. Since such a lower end surface 70b has a large area in contact with the inert gas supplied from the upstream side, the pressure loss of the inert gas passing through the inside of the porous body 70 can be suppressed to be small, and the holding device 100 of this embodiment is provided with a holding substrate 10 in which the substrate side gas flow path (an example of a gas flow path) 12 is filled with the porous body 70 having such excellent gas permeability.

[0059] <Embodiment 2> Next, a holding substrate 10A provided in a holding device according to embodiment 2 will be described with reference to Fig. 7. Fig. 7 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path 12A of the holding substrate 10A according to embodiment 2. The basic configuration of the holding substrate 10A of this embodiment is the same as that of embodiment 1. Therefore, in Fig. 7, parts corresponding to those of embodiment 1 are denoted by the same reference numerals as those of embodiment 1 with the addition of the reference numeral "A", and detailed description thereof will be omitted.

[0060] The holding substrate 10A includes a disk-shaped plate-like member 11A and a substrate-side gas flow path 12A formed therein. The upper surface of the plate-like member 11A is a first surface SA1 of the holding substrate 10A, and the lower surface of the plate-like member 11A is a second surface SA2 of the holding substrate 10A. A chuck electrode 40A is provided inside the holding substrate 10A.

[0061] 7, the substrate-side gas flow path 12A includes a first vertical flow path section 120A, a horizontal flow path section 130A, and a second vertical flow path section 140A. A gas-permeable porous body 70A containing ceramics as a main component is filled in the first vertical flow path section 120A, which is a part of the substrate-side gas flow path 12A.

[0062] The first vertical flow path section 120A includes a gas outlet 12Ab that opens on the first surface SA1 side, and is a flow path extending from the gas outlet 12Ab to the second surface SA2 side along the thickness direction of the plate-like member 11A. The first vertical flow path section 120A has a substantially cylindrical shape extending in the vertical direction, and an opening 12Ac that is an inlet of the first vertical flow path section 120A and has substantially the same diameter as the gas outlet 12Ab is provided on the opposite side to the gas outlet 12Ab. The first vertical flow path section 120A is composed of a section between the gas outlet 12Ab and the opening 12Ac in the substrate-side gas flow path 12A.

[0063] The horizontal flow path section 130A is a flow path that is connected to the first vertical flow path section 120A and extends parallel to the first surface SA1. The downstream side of the horizontal flow path section 130A is connected to the opening 12Ac located on the upstream side of the first vertical flow path section 120A.

[0064] The horizontal flow path section 130A includes a bottom horizontal flow path section 131A including a bottom 131Aa that faces the porous body 70A filled in the first vertical flow path section 120A, and a main body horizontal flow path section 132A that connects between the bottom horizontal flow path section 131A and the second vertical flow path section 140A.

[0065] The bottom 131Aa of the bottom horizontal flow path section 131A is substantially circular in plan view and is set to be substantially the same size as the gas outlet 12Ab and the opening 12Ac. The surface (bottom surface) 131Aa1 of the bottom 131Aa is flat. The bottom horizontal flow path section 131A has a substantially cylindrical peripheral wall section 131Ab that rises from the periphery of the bottom 131Aa toward the first surface SA1. The peripheral wall section 131Ab is provided with an opening 131Ac, which is connected to the downstream side of the main body horizontal flow path section 132A. The bottom horizontal flow path section 131A forms a flat flow path that spreads parallel to the first surface SA1.

[0066] The main body horizontal channel section 132A forms an elongated channel extending parallel to the first surface SA1, with its upstream side connected to the second vertical channel section 140A and its downstream side connected to the opening 131Ac of the bottom horizontal channel section 131A.

[0067] The second vertical flow path section 140A includes an inlet 12Aa that opens on the second surface SA2, and is a flow path that extends from the inlet 12Aa to the first surface SA1 side along the thickness direction of the plate-like member 11A. The downstream side of the second vertical flow path section 140A is connected to the upstream side of the horizontal flow path section 130A.

[0068] The porous body 70A is filled in the first vertical flow passage section 120A so that a space VA is formed below the porous body 70A. The upper end surface 70Aa of the porous body 70A is flat and has a circular shape in a plan view. The upper end surface 70Aa is exposed from the gas outlet 12Ab. In this embodiment, the first surface SA1 and the upper end surface 70Aa are arranged to be flush with each other.

[0069] In contrast, the lower end surface of the porous body 70A forms a convex end surface 70Ab that rises toward the second surface SA2. The convex end surface 70Ab is the end surface (lower end surface) on the second surface side of the porous body 70A that faces the space VA. The convex end surface 70Ab has a substantially circular shape in a plan view, and gradually rises toward the second surface SA2 from the periphery toward the center.

[0070] The porous body 70A is filled in the cylindrical first vertical channel section 120A with the convex end surface 70Ab exposed to the space VA from the opening 12Ac and entering the bottom horizontal channel section 131A. The space VA is surrounded by the convex end surface 70Ab, which is the lower end surface of the porous body 70A, the surface (bottom surface) 131Aa1 of the bottom 131Aa, and the surface of the peripheral wall section 131Ab. The horizontal channel section 130A has a space VA in the bottom horizontal channel section 131A arranged at one end on the downstream side. The bottom 131Aa of the bottom horizontal channel section 131A is provided at a position overlapping with the convex end surface 70Ab (upper end surface 70Ab) of the porous body 70A in a plan view.

[0071] Such a porous body 70A is filled into the first vertical flow path section 120A so that a space VA is formed on the second surface SA2 side (i.e., the convex end face 70Ab side) of the porous body 70A within the bottom horizontal flow path section 131A of the horizontal flow path section 130A.

[0072] The peripheral surface 70Ac of the porous body 70A has a cylindrical shape extending straight in the vertical direction. The porous body 70A and the peripheral wall portion 111A constituting the first vertical flow path portion 120A are joined to each other by sintering.

[0073] A convex end surface 70Ab, which is the lower end surface of the porous body 70A, faces the space VA in the horizontal flow passage section 130A (bottom horizontal flow passage section 131A), and the inert gas supplied from the upstream side of the substrate side gas flow passage (gas flow passage) 12A is supplied from this convex end surface 70Ab into the porous body 70A. The convex end surface 70Ab is porous, and its surface area is larger than that of a flat end surface.

[0074] In the holding device of the present embodiment as described above, the porous body 70A filled in the first vertical flow passage section (an example of a vertical flow passage section) 120A of the substrate-side gas flow passage (an example of a gas flow passage) 12A has a convex end face (lower end face) 70Ab, which is an end face on the second surface SA2 side, which is inserted into the bottom horizontal flow passage section 131A, which is a part of the horizontal flow passage section 130A. A space VA (gap) is present between such a convex end face (lower end face) 70Ab and the bottom part 131Aa of the bottom horizontal flow passage section 131A facing it, and the entire convex end face 70Ab facing the space VA functions as an inlet for supplying an inert gas to the inside of the porous body 70A. Since such a convex end face 70Ab has a particularly large area in contact with the inert gas supplied from the upstream side, the pressure loss of the inert gas passing through the inside of the porous body 70A can be suppressed to a small value, and the gas permeability is excellent.

[0075] As described above, the holding device of this embodiment includes a holding substrate 10A in which the substrate-side gas flow passage 12A is filled with the porous body 70A having excellent gas permeability.

[0076] <Embodiment 3> Next, a holding substrate 10B provided in a holding device according to embodiment 3 will be described with reference to Fig. 8. Fig. 8 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path 12B of a holding substrate 10B according to embodiment 3. The basic configuration of the holding substrate 10B of this embodiment is the same as that of embodiment 1. Therefore, in Fig. 8, parts corresponding to those of embodiment 1 are denoted by the same reference numerals as those of embodiment 1 with the addition of the reference numeral "B", and detailed description thereof will be omitted.

[0077] The holding substrate 10B includes a disk-shaped plate-like member 11B and a substrate-side gas flow path 12B formed therein. The upper surface of the plate-like member 11B is a first surface SB1 of the holding substrate 10B, and the lower surface of the plate-like member 11B is a second surface SB2 of the holding substrate 10B. A chuck electrode 40B is provided inside the holding substrate 10B.

[0078] 8, the substrate-side gas flow path 12B includes a first vertical flow path section 120B, a horizontal flow path section 130B, and a second vertical flow path section 140B. A gas-permeable porous body 70B mainly composed of ceramics is filled in the first vertical flow path section 120B, which is a part of the substrate-side gas flow path 12B.

[0079] The first vertical flow passage section 120B includes a gas outlet 12Bb that opens on the first surface SB1 side, and is a flow passage extending from the gas outlet 12Bb to the second surface SB2 side along the thickness direction of the plate-like member 11B. The first vertical flow passage section 120B has a generally cylindrical shape extending in the vertical direction, and an opening 12Bc, which is an inlet of the first vertical flow passage section 120B and has a diameter generally the same as that of the gas outlet 12Bb, is provided on the opposite side of the gas outlet 12Bb. The first vertical flow passage section 120B is composed of a section between the gas outlet 12Bb and the opening 12Bc in the substrate-side gas flow passage 12B.

[0080] The horizontal flow path section 130B is a flow path that is connected to the first vertical flow path section 120B and extends parallel to the first surface SB1. The downstream side of the horizontal flow path section 130B is connected to the opening 12Bc located on the upstream side of the first vertical flow path section 120B.

[0081] The horizontal flow path section 130B comprises a bottom horizontal flow path section 131B including a bottom 131Ba that faces the porous body 70B filled in the first vertical flow path section 120B, and a main body horizontal flow path section 132B that connects between the bottom horizontal flow path section 131B and the second vertical flow path section 140B.

[0082] The bottom 131Ba of the bottom horizontal flow passage section 131B is substantially circular in plan view and is set to be substantially the same size as the gas outlet 12Bb and the opening 12Bc. The surface (bottom surface) 131Ba1 of the bottom 131Ba is flat. The bottom horizontal flow passage section 131B has a substantially cylindrical peripheral wall section 131Bb that rises from the periphery of the bottom 131Ba toward the first surface SB1. The peripheral wall section 131Bb is provided with an opening 131Bc, which is connected to the downstream side of the main body horizontal flow passage section 132B. The bottom horizontal flow passage section 131B forms a flat flow passage that spreads parallel to the first surface SB1.

[0083] The main body horizontal channel section 132B forms an elongated channel extending parallel to the first surface SB1, with its upstream side connected to the second vertical channel section 140B and its downstream side connected to the opening 131Bc of the bottom horizontal channel section 131B.

[0084] The second vertical flow path section 140B includes an inlet 12Ba that opens on the second surface SB2, and is a flow path that extends from the inlet 12Ba to the first surface SB1 side along the thickness direction of the plate-shaped member 11B. The downstream side of the second vertical flow path section 140B is connected to the upstream side of the horizontal flow path section 130B.

[0085] The porous body 70B is filled in the first vertical flow passage section 120B so that a space VB is formed below the porous body 70B. The upper end surface 70Ba of the porous body 70B is flat and has a circular shape in a plan view. The upper end surface 70Ba is exposed from the gas outlet 12Bb. In this embodiment, the first surface SB1 and the upper end surface 70Ba are arranged to be flush with each other.

[0086] In contrast, the lower end surface of the porous body 70B is a concave end surface 70Bb recessed toward the first surface SB1. The concave end surface 70Bb is an end surface (lower end surface) on the second surface side of the porous body 70B facing the space VB. The concave end surface 70Bb has a substantially circular shape in a plan view, and is gradually recessed toward the first surface SB1 from the periphery toward the center.

[0087] The porous body 70B is filled in the cylindrical first vertical flow path section 120B with the concave end surface 70Bb exposed to the space VB from the opening 12Bc and recessed into the first vertical flow path section 120B. The space VB is surrounded by the concave end surface 70Bb, which is the lower end surface of the porous body 70B, the surface (bottom surface) 131Ba1 of the bottom 131Ba, and the surface of the peripheral wall section 131Bb. The horizontal flow path section 130B has a space VB in the bottom horizontal flow path section 131B arranged at one end on the downstream side. The bottom 131Ba of the bottom horizontal flow path section 131B is provided at a position overlapping with the concave end surface 70Bb (upper end surface 70Bb) of the porous body 70B in a plan view.

[0088] Such a porous body 70B is filled into the first vertical flow path section 120B so that a space VB is formed on the second surface SB2 side (i.e., the concave end surface 70Bb side) of the porous body 70B within the bottom horizontal flow path section 131B of the horizontal flow path section 130B.

[0089] The porous body 70B has a circumferential surface 70Bc that is cylindrical and extends vertically in a straight line. The porous body 70B and the circumferential wall portion 111B that constitutes the first vertical flow path portion 120B are joined to each other by sintering.

[0090] The concave end face 70Bb, which is the lower end face of the porous body 70B, faces the space VB in the horizontal flow passage section 130B (bottom horizontal flow passage section 131B), and the inert gas supplied from the upstream side of the substrate side gas flow passage (gas flow passage) 12B is supplied into the porous body 70B from this concave end face 70Bb. The concave end face 70Bb is porous, and its surface area is larger than that of a flat end face. In addition, the thickness (length in the height direction) of the porous body 70B is smaller at the center side of the concave end face 70Bb in a plan view than around it.

[0091] In the holding device of the present embodiment as described above, the porous body 70B filled in the first vertical flow passage section (an example of a vertical flow passage section) 120B of the substrate-side gas flow passage (an example of a gas flow passage) 12B has a concave end face (lower end face) 70Bb, which is an end face on the second surface SB2 side, recessed into the first vertical flow passage section 120B. Between such a concave end face (lower end face) 70Bb and the bottom 131Ba of the bottom horizontal flow passage section 131B facing it, there is a space VB (gap), and the entire concave end face 70Bb facing the space VB functions as an inlet for supplying an inert gas to the inside of the porous body 70B. Since such a concave end face 70Bb has a particularly large area in contact with the inert gas supplied from the upstream side, the pressure loss of the inert gas passing through the inside of the porous body 70B can be suppressed to a small value, and furthermore, since the thickness of the central side of the porous body 70B is small as described above, it has excellent gas permeability.

[0092] As described above, the holding device of this embodiment includes a holding substrate 10B in which the substrate-side gas flow passage 12B is filled with the porous body 70B having excellent gas permeability.

[0093] <Embodiment 4> Next, a holding substrate 10C provided in a holding device according to embodiment 4 will be described with reference to Fig. 9. Fig. 9 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path 12C of a holding substrate 10C according to embodiment 4. The basic configuration of the holding substrate 10C of this embodiment is the same as that of embodiment 1. Therefore, in Fig. 9, parts corresponding to those of embodiment 1 are denoted by the same reference numerals as those of embodiment 1 with the addition of the reference numeral "C", and detailed description thereof will be omitted.

[0094] The holding substrate 10C includes a disk-shaped plate-like member 11C and a substrate-side gas flow path 12C formed therein. The upper surface of the plate-like member 11C is a first surface SC1 of the holding substrate 10C, and the lower surface of the plate-like member 11C is a second surface SC2 of the holding substrate 10C. A chuck electrode 40C is provided inside the holding substrate 10C.

[0095] 9, the substrate-side gas flow path 12C includes a first vertical flow path section 120C, a horizontal flow path section 130C, and a second vertical flow path section 140C. A gas-permeable porous body 70C mainly composed of ceramics is filled in the first vertical flow path section 120C, which is a part of the substrate-side gas flow path 12C.

[0096] The first vertical flow passage section 120C includes a gas outlet 12Cb that opens on the first surface SC1 side, and is a flow passage extending from the gas outlet 12Cb to the second surface SC2 side along the thickness direction of the plate-like member 11C. The first vertical flow passage section 120C has a generally cylindrical shape extending in the vertical direction, and an opening 12Cc, which is an inlet of the first vertical flow passage section 120C and has a diameter generally the same as that of the gas outlet 12Cb, is provided on the opposite side of the gas outlet 12Cb. The first vertical flow passage section 120C is composed of a section between the gas outlet 12Cb and the opening 12Cc in the substrate-side gas flow passage 12C.

[0097] The horizontal flow path portion 130C is a flow path that is connected to the first vertical flow path portion 120C and extends parallel to the first surface SC1. The downstream side of the horizontal flow path portion 130C is connected to the opening 12Cc located on the upstream side of the first vertical flow path portion 120C.

[0098] The horizontal flow path section 130C includes a bottom horizontal flow path section 131C including a bottom 131Ca that faces the porous body 70C filled in the first vertical flow path section 120C, and a main body horizontal flow path section 132C that connects between the bottom horizontal flow path section 131C and the second vertical flow path section 140C.

[0099] The bottom 131Ca of the bottom horizontal flow passage section 131C is substantially circular in plan view and is set to be substantially the same size as the gas outlet 12Cb and the opening 12Cc. The surface (bottom surface) 131Ca1 of the bottom 131Ca is flat. The bottom horizontal flow passage section 131C has a substantially cylindrical peripheral wall section 131Cb rising from the periphery of the bottom 131Ca toward the first surface SC1 side. The peripheral wall section 131Cb is provided with an opening 131Cc, which is connected to the downstream side of the main body horizontal flow passage section 132C. The bottom horizontal flow passage section 131C forms a flat flow passage that spreads parallel to the first surface SC1.

[0100] The main body horizontal channel portion 132C forms an elongated channel extending parallel to the first surface SC1, with its upstream side connected to the second vertical channel portion 140C and its downstream side connected to the opening 131Cc of the bottom horizontal channel portion 131C.

[0101] The second vertical flow path section 140C includes an inlet 12Ca that opens on the second surface SC2, and is a flow path extending from the inlet 12Ca to the first surface SC1 side along the thickness direction of the plate-like member 11C. The downstream side of the second vertical flow path section 140C is connected to the upstream side of the horizontal flow path section 130C.

[0102] The porous body 70C is filled in the first vertical flow path section 120C so as to form a space VC below the porous body 70C. The porous body 70C has a substantially cylindrical main body section 71C filled in the first vertical flow path section 120C, and a support section 72C extending from the main body section 71C to the bottom surface 131Ca1 so that the space VC is formed on the second surface SC2 side of the main body section 71C and the main body section 71C is supported on the bottom surface 131Ca1.

[0103] The upper end surface 70Ca of the porous body 70C is a flat upper end surface of the main body 71C and has a circular shape in a plan view. The upper end surface 70Ca is exposed from the gas outlet 12Cb. In this embodiment, the first surface SC1 and the upper end surface 70Ca are arranged to be flush with each other.

[0104] The lower end surface 70Cb of the main body 71C of the porous body 70C is generally flat and is set at the height of the opening 12Cc. Such a lower end surface 70Cb faces the bottom surface 131Ca1 of the bottom 131Ca with a space VC therebetween. The above-mentioned support portion 72C is provided on the edge side of the lower end surface 70Cb (the side opposite the opening 131Cc in the bottom horizontal channel portion 131C). The support portion 72C extends from the lower end surface 70Cb side of the main body 71C to the bottom surface 131Ca1 of the bottom horizontal channel portion 131C.

[0105] The porous body 70C is filled in the cylindrical first vertical flow path section 120C with the lower end side of the porous body 70C including the lower end surface 70Cb and the support portion 72Cb exposed to the space VC from the opening 12Cc, and the support portion 72Cb extending to the bottom surface 131Ca1 of the bottom horizontal flow path section 131C. The space VC is surrounded by the lower end surface 70Cb and the support portion 72Cb constituting the lower end side of the porous body 70C, the surface (bottom surface) 131Ca1 of the bottom portion 131Ca, and the surface of the peripheral wall portion 131Cb. The horizontal flow path section 130C has a space VC in the bottom horizontal flow path section 131C arranged at one end on the downstream side. The bottom portion 131Ca of the bottom horizontal flow path section 131C is provided at a position overlapping the lower end side (upper end surface 70Bb) of the porous body 70B in a plan view.

[0106] Such a porous body 70C is filled into the first vertical flow path section 120C so that a space VC is formed on the second surface SC2 side (i.e., the lower end surface 70Cb side) of the porous body 70C within the bottom horizontal flow path section 131C of the horizontal flow path section 130C.

[0107] The peripheral surface 70Cc of the porous body 70C is generally cylindrical and extends vertically. The main body 71C of the porous body 70C and the peripheral wall 111C constituting the first vertical flow passage 120C are joined to each other by sintering. In the present embodiment, a part of the support 72Cb and a part of the peripheral wall 131Cb are joined to each other by sintering.

[0108] The lower end surface 70Cb and the support portion 72Cb of the porous body 70C face the space VC in the horizontal flow passage portion 130C (bottom horizontal flow passage portion 131C), and the inert gas supplied from the upstream side of the substrate side gas flow passage (gas flow passage) 12C is supplied into the porous body 70C from the lower end surface 70Cb and the support portion 72Cb. The lower end surface 70Cb and the support portion 72Cb are porous, and have a large area that can come into contact with the inert gas. The porous body 70C is supported on the bottom portion 131Ca (bottom surface 131Ca1) by the support portion 72Cb, and is fixed to a part of the peripheral wall portion 131Cb.

[0109] In the holding device of the present embodiment as described above, there is a space VC (gap) between the lower end surface 70Cb etc. on the second surface SC2 side of the porous body 70C filled in the first vertical flow passage section (an example of a vertical flow passage section) 120C of the substrate side gas flow passage (an example of a gas flow passage) 12C and the bottom 131Ca of the bottom horizontal flow passage section 131C facing thereto, and the entire lower end surface 70Cb and the support section 72Cb facing the space VC function as an inlet for supplying an inert gas to the inside of the porous body 70C. Such lower end surface 70Cb etc. has a large area in contact with the inert gas supplied from the upstream side, so that the pressure loss of the inert gas passing through the inside of the porous body 70C can be suppressed to a small value. Furthermore, as described above, the lower end side of the porous body 70C is supported on the bottom 131Ca (bottom surface 131Ca1) by the support portion 72Cb, so that during manufacture of the holding device (holding substrate 10C) (during degreasing and firing and main firing), the porous body 70C is prevented from falling off into the space VC from the hole portion for forming the first vertical flow path portion 120C.

[0110] As described above, the holding device of this embodiment includes a holding substrate 10C in which the substrate-side gas flow passage 12C is filled with the porous body 70C having excellent gas permeability.

[0111] <Embodiment 5> Next, a holding substrate 10D provided in a holding device according to embodiment 5 will be described with reference to Fig. 10. Fig. 10 is an enlarged cross-sectional view of a portion of a substrate-side gas flow path 12D of a holding substrate 10D according to embodiment 5. The basic configuration of the holding substrate 10D of this embodiment is the same as that of embodiment 1. Therefore, in Fig. 10, parts corresponding to those of embodiment 1 are denoted by the same reference numerals as those of embodiment 1 with the addition of the reference numeral "D", and detailed description thereof will be omitted.

[0112] The holding substrate 10D includes a disk-shaped plate-like member 11D and a substrate-side gas flow path 12D formed therein. The upper surface of the plate-like member 11D is a first surface SD1 of the holding substrate 10D, and the lower surface of the plate-like member 11D is a second surface SD2 of the holding substrate 10D. A chuck electrode 40D is provided inside the holding substrate 10D.

[0113] 10, the substrate-side gas flow path 12D includes a first vertical flow path section 120D, a horizontal flow path section 130D, and a second vertical flow path section 140D. A gas-permeable porous body 70D containing ceramics as a main component is filled in the first vertical flow path section 120D, which is a part of the substrate-side gas flow path 12D.

[0114] The first vertical flow path section 120D includes a gas outlet 12Db that opens on the first surface SD1 side, and is a flow path extending from the gas outlet 12Db to the second surface SD2 side along the thickness direction of the plate-like member 11D. The first vertical flow path section 120D is cylindrical with a small inner diameter on the upper side and a large inner diameter on the lower side, and an opening 12Dc is provided on the opposite side to the gas outlet 12Db, which is an inlet of the first vertical flow path section 120D and has an inner diameter larger than the inner diameter r of the gas outlet 12Db. The first vertical flow path section 120D is composed of a section between the gas outlet 12Db and the opening 12Dc in the substrate-side gas flow path 12D.

[0115] Such a first vertical flow path section 120D is provided with a small diameter accommodating section 121 arranged at the upper end (first surface SD1 side) and including a gas flow outlet 12Db, and a wide diameter accommodating section 122D connected to the lower end (second surface SD2 side) of the small diameter accommodating section 121 and having an inner diameter larger than that of the small diameter accommodating section 121D.

[0116] The small diameter housing portion 121D is a cylindrical hole portion that includes a circumferential surface that extends straight from the gas outlet 12Db toward the second surface SD2 along the thickness direction of the plate-shaped member 11D.

[0117] The wide accommodating portion 122D consists of a wide inclined accommodating portion 123D connected to the lower end (second surface SD2 side) of the small diameter accommodating portion 121D, and a wide large diameter accommodating portion 124D connected to the lower end (second surface SD2 side) of the wide inclined accommodating portion 123D.

[0118] The wide inclined housing portion 123D is a cylindrical hole including an annular inclined peripheral surface that is inclined so as to widen outward from the first surface SD1 side toward the second surface SD2 side. The wide large diameter housing portion 124 is a cylindrical hole that extends straight from the wide inclined housing portion 123 toward the second surface SD2 side along the thickness direction of the plate-like member 11D and includes a peripheral surface with an inner diameter larger than that of the small diameter housing portion 121D.

[0119] The horizontal flow path section 130D is a flow path that is connected to the first vertical flow path section 120D and extends parallel to the first surface SD1. The downstream side of the horizontal flow path section 130D is connected to the opening 12Dc located on the upstream side of the first vertical flow path section 120D.

[0120] The horizontal flow path section 130D comprises a bottom horizontal flow path section 131D including a bottom 131Da that faces the porous body 70D filled in the first vertical flow path section 120D, and a main body horizontal flow path section 132D that connects between the bottom horizontal flow path section 131D and the second vertical flow path section 140D.

[0121] The bottom 131Da of the bottom horizontal flow path section 131D is substantially circular in plan view and is set to be substantially the same size as the opening 12Dc. The surface (bottom surface) 131Da1 of the bottom 131Da is flat. The bottom horizontal flow path section 131D has a substantially cylindrical peripheral wall section 131Db that rises from the periphery of the bottom 131Da toward the first surface SD1. The peripheral wall section 131Db is provided with an opening 131Dc, which is connected to the downstream side of the main body horizontal flow path section 132D. The bottom horizontal flow path section 131D forms a flat flow path that spreads parallel to the first surface SD1.

[0122] The main body horizontal channel section 132D forms an elongated channel extending parallel to the first surface SD1, with its upstream side connected to the second vertical channel section 140D and its downstream side connected to the opening 131Dc of the bottom horizontal channel section 131D.

[0123] The second vertical flow path section 140D includes an inlet 12Da that opens on the second surface SD2, and is a flow path that extends from the inlet 12Da to the first surface SD1 side along the thickness direction of the plate-shaped member 11D. The downstream side of the second vertical flow path section 140D is connected to the upstream side of the horizontal flow path section 130D.

[0124] The porous body 70D is filled in the first vertical flow passage section 120D so that a space VD is formed below the porous body 70D. The upper end surface 70Da of the porous body 70D is flat and has a circular shape in a plan view. The upper end surface 70Da is exposed from the gas outlet 12Db. In this embodiment, the first surface SD1 and the upper end surface 70Da are arranged to be flush with each other.

[0125] The lower end surface 70Db of the porous body 70D is an end surface on the second surface SD2 side of the porous body 70D facing the space VD, and has a substantially circular shape larger than the upper end surface 70Da in plan view.

[0126] The porous body 70D has a cylindrical tip portion 71D filled on the first surface SD1 side within the first vertical flow path section 120D, and an approximately cylindrical wide portion 72D connected to the lower end (second surface SD2 side) of the tip portion 71D.

[0127] The wide portion 72D is disposed closer to the second surface SD2 than the gas outlet 12Db, and has a larger radial size than the gas outlet 12Db. The wide portion 72D has an inclined portion 73D including an annular inclined surface 73Da that is inclined so as to widen from the first surface SD1 side toward the second surface SD2 side, and a cylindrical columnar portion 74D that extends straight from the inclined portion 73D toward the second surface S2 side. The lower end surface 70Db of the columnar portion 74D is set at approximately the same height as the upper portion of the horizontal flow passage portion 130D.

[0128] The lower end surface 70Db is exposed to the space VD side from the opening 12Dc, and an inert gas is supplied into the porous body 70D from the lower end surface 70Db. The opening 12Dc is located on the opposite side of the gas outlet 12Db, and is disposed closer to the first surface SD1 than the bottom horizontal flow passage section 130D, and opens to the bottom 131Da side so as to expose the second surface SD2 side of the porous body 70D to the bottom 131Da side. The lower end surface 70Db (second surface SD2 side) of the porous body 70D (columnar section 74D) exposed from such an opening 12Dc faces the surface (bottom surface) 131Da1 of the bottom 131Da entirely. In this embodiment, the size of the surface (bottom surface) 131Da1 of the bottom 131Da is the same as the size of the lower end surface 70Db. A main body horizontal channel section 132D extending parallel to the first surface SD1 is connected to a bottom horizontal channel section 130D including the bottom section 131Da.

[0129] In this way, the lower end surface 70Db of the porous body 70D is completely opposed to the bottom 131Da of the bottom horizontal flow path section 131D which is not filled with the porous body 70D, so that a sufficient flow rate of inert gas can be introduced into the porous body 70D.

[0130] In the porous body 70D of this embodiment, the angle θ between the peripheral surface 71Db of the tip portion 71D connected to the first surface SD1 side of the wide portion 72D (inclined portion 73D) and the inclined surface 73Da of the inclined portion 73D is set so that 90°<θ<180°. If set in this way, even if a force acting from the second surface SD2 side to the first surface SD1 side acts on the paste for forming the porous body 70D during manufacturing of the holding substrate 10D (during degreasing and baking, etc.), and the paste for the porous body tries to move from the second surface SD2 side to the first surface SD1 side in the hole for forming the first vertical flow path section 120D, the part corresponding to the wide part 72D of the porous body 70D is caught (locked) by the part corresponding to the annular corner part (part constituting the periphery of the small diameter storage part 121D and the periphery of the wide inclined storage part 123D) 111Da of the peripheral wall part 111D constituting the first vertical flow path section 120D, which is arranged around the porous body 70D. Therefore, the paste for the porous body in the hole for forming the first vertical flow path section 120D is deformed, etc., and the porous body 70D is prevented from falling out of the first vertical flow path section 120D. As a result, in the holding device of this embodiment, the porous body 70D can be placed at a predetermined location in the substrate side gas flow path 12D.

[0131] The upper end surface 70Da of the porous body 70D is the upper end surface of the tip portion 71D, and the lower end surface 70Db of the porous body 70D is the lower end surface of the wide portion 72D (columnar portion 72D2). The lower end surface 70Db of the porous body 70D is set at approximately the same height as the opening 12Dc.

[0132] The porous body 70D is filled in the first vertical flow path section 120D with the lower end surface 70Db exposed to the space VD side from the opening 12Dc. The space VD is surrounded by the lower end surface 70Db of the porous body 70D, the surface (bottom surface) 131Da1 of the bottom portion 131Da, and the surface of the peripheral wall portion 131Db. The horizontal flow path section 130D has a space VD in the bottom horizontal flow path section 131D arranged at one end on the downstream side. The bottom portion 131Da of the bottom horizontal flow path section 131D is provided at a position overlapping with the lower end surface 70Db of the porous body 70D in a plan view.

[0133] Such a porous body 70D is filled in the first vertical flow path section 120D so that a space VD is formed in the bottom horizontal flow path section 131D of the horizontal flow path section 130D on the second surface SD2 side (i.e., the lower end surface 70Db side) of the porous body 70D. The peripheral surface of the porous body 70D and the peripheral wall section 111D constituting the first vertical flow path section 120D are joined to each other by sintering.

[0134] The lower end surface 70Db of the porous body 70D faces the space VD in the horizontal flow passage section 130D (bottom horizontal flow passage section 131D), and the inert gas supplied from the upstream side of the substrate side gas flow passage 12D is supplied into the porous body 70D from this lower end surface 70Db. The area of ​​the lower end surface 70Db that comes into contact with the inert gas (i.e., the area exposed to the space V) is large.

[0135] In the holding device of this embodiment as described above, there is a space VD (gap) between the lower end surface 70Db of the porous body 70D filled in the first vertical flow passage section (an example of a vertical flow passage section) 120D of the substrate-side gas flow passage (an example of a gas flow passage) 12D and the bottom 131Da of the bottom horizontal flow passage section 131D facing it, and the entire lower end surface 70Db facing the space VD functions as an inlet for supplying an inert gas into the inside of the porous body 70D. Since such a lower end surface 70Db has a particularly large area in contact with the inert gas supplied from the upstream side, the pressure loss of the inert gas passing through the inside of the porous body 70D can be suppressed to a small value, and the gas permeability is excellent.

[0136] As described above, the holding device of this embodiment includes a holding substrate 10D in which the substrate-side gas flow passage 12D is filled with the porous body 70D having excellent gas permeability.

[0137] In the present embodiment, the porous body 70D has a wide portion 72D on the second surface SD2 side that has an outer diameter larger than the inner diameter r of the gas outlet 12Db, so that even if a force acting from the second surface SD2 side to the first surface SD1 side acts on the paste for the porous body for forming the porous body 70D during the manufacturing of the holding substrate 10D (during degreasing and baking, etc.), and the paste for the porous body tries to move from the second surface SD2 side to the first surface SD1 side in the hole for forming the first vertical flow path section 120D, the part corresponding to the wide portion 72D of the porous body 70D is caught by the part corresponding to the peripheral wall portion 111D constituting the first vertical flow path section 120D, which is arranged around the porous body 70D. Therefore, the paste for the porous body in the hole for forming the first vertical flow path section 120D is deformed, etc., and the porous body 70D is prevented from falling out of the first vertical flow path section 120D.

[0138] In particular, the porous body 70D of this embodiment is composed of a tip portion 71D, an inclined portion 73D, and a wide portion 74D connected in this order from the first surface SD1 side to the second surface SD2 side. The tip portion 71D is cylindrical, and an inclined portion 73D wider than the tip portion 71D is connected to its lower end. The inclined portion 73D includes an inclined surface 73Da that inclines so as to widen from the first surface SD1 side toward the second surface SD2 side, and the cylindrical portion 74D is provided in a form that extends in a straight columnar shape from the inclined surface 73Da (inclined portion 73D) to the second surface SD2 side. That is, in the porous body 70D of this embodiment, in the thickness direction of the plate-shaped member 11D, the inclined portion 73D including the inclined surface 73Da is sandwiched between the cylindrical tip portion 71D that extends in a straight line and the columnar portion 74D that extends in a straight line.

[0139] When the porous body 70D has such a configuration, the porous body 70D is less likely to be displaced, and the adhesion between the porous body 70D and the plate-like member 11D (peripheral wall portion 111D) arranged therearound is improved. In the manufacturing process of the holding substrate 10D, a laminate (molded body) of green sheets for forming the plate-like member 11D is fired. The laminate has holes for forming the first vertical flow path portion 120D, and the holes are filled with a paste for a porous body for forming the porous body 70D. When such a laminate is fired, the laminate of green sheets arranged therearound (the portion corresponding to the peripheral wall portion 111D) shrinks more (especially in the in-plane direction) than the paste for a porous body for forming the porous body 70D filled in the holes, so that the paste for a porous body in the holes is clamped by the laminate of green sheets arranged therearound. Therefore, as described above, the porous body 70D of this embodiment is less likely to shift position and has better adhesion to the plate-shaped member 11D (circumferential wall portion 111D) arranged around it than, for example, a porous body consisting only of a tip portion and an inclined portion (wherein the lower end surface of the inclined portion is exposed from the opening 12Dc) or a truncated cone-shaped porous body that is inclined so as to widen from the gas flow outlet 12Db side (first surface SD1 side) toward the opening 12Dc side (second surface SD2 side).

[0140] Furthermore, since the porous body 70D of this embodiment includes the tip portion 71D, the inclined portion 73D, and the columnar portion 74D, the volume of the porous body 70D can be kept to a necessary minimum, as compared with the porous body in which the angle θ is 90° as shown in Fig. 10. The holding substrate 10D including the porous body 70D of this embodiment can maintain high strength while relatively increasing the ratio of the ceramic portion (alumina) constituting the plate-like member 11D.

[0141] <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.

[0142] (1) The upper end surface of the porous body exposed from the gas outlet may have a shape other than a circle (such as a polygon) as long as the object of the present invention is not impaired.

[0143] (2) The upper end surface of the porous body may be located below the first surface as long as this does not impair the object of the present invention.

[0144] (3) The number of support parts formed on the second surface side of the porous body and supported by the bottom part (bottom surface) of the lateral flow passage part may be one or two or more.

[0145] (4) 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.

[0146] (5) 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. [Explanation of symbols]

[0147] 100...holding device, 10...holding substrate, 11...plate-shaped member, 12...substrate-side gas flow path (gas flow path), 12b...gas outlet, 120...first vertical flow path section (vertical flow path section), 130...horizontal flow path section, 140...second vertical flow path section, 70...porous body, 70a...upper end surface, 70b...lower end surface, V...space, S1...first surface, S2...second surface, W...wafer (object)

Claims

1. A holding device comprising a holding substrate including a first surface for holding an object and a second surface disposed on an opposite side of the first surface, the holding substrate having a plate-like member mainly made of ceramics, a gas flow path formed inside the plate-like member, and a gas-permeable porous body mainly made of ceramics that is filled in a part of the gas flow path, the gas flow path includes a gas outflow outlet that opens to the first surface side, and has a vertical flow path portion that extends from the gas outflow outlet to the second surface side, and a horizontal flow path portion that is connected to the vertical flow path portion and extends parallel to the first surface, The porous body is filled in the vertical flow path section such that a space is formed in the horizontal flow path section on the second surface side of the porous body, A holding device in which the upper end surface of the porous body is arranged closer to the first surface than the second surface.

2. The lateral flow path portion includes a bottom surface facing the porous body and a ceiling surface facing the bottom surface, The holding device according to claim 1 , wherein the side surface of the porous body that contacts the inner surface of the vertical flow path portion extends to the ceiling surface of the horizontal flow path portion.

3. The holding device according to claim 1 , wherein the porous body has an end face on the second surface side facing the space, the end face having a protruding convex shape on the second surface side.

4. The holding device according to claim 1 , wherein the porous body has an end face on the second surface side facing the space, and a concave end face recessed on the first surface side.

5. The lateral flow path portion includes a bottom surface facing the porous body, The holding device described in claim 1, wherein the porous body has a main body portion filled in the vertical flow path portion, and a support portion extending from the main body portion to the bottom surface so that the space is formed on the second surface side of the main body portion and the main body portion is supported on the bottom surface.

6. The holding device according to claim 1 , wherein the porous body is disposed closer to the second surface than the gas outlet and has a wide portion that is wider than the gas outlet in the radial direction.

7. The holding device according to claim 1 , wherein the space is provided at one end of the lateral flow path portion.

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