Holding device

Abstract

This invention provides a technology to improve the temperature distribution on the mounting surface of a plate-shaped member in a holding device. [Solution] The holding device is a plate-shaped member having a pair of main surfaces, the plate-shaped member having a mounting surface formed on one of the pair of main surfaces on which an object is placed, a flow path disposed inside the plate-shaped member through which a refrigerant flows, and a hole formed along a direction intersecting each of the pair of main surfaces, the flow path having a branching and merging section including a branching section that branches the flow path into two branched flow paths, and a merging section that merges the two branched flow paths into one, and there is no hole between the two branched flow paths.

Description

Technical Field

[0001] The present invention relates to a holding device.

Background Art

[0002] Conventionally, a holding device including a plate-like member having a placement surface on which an object is placed and a flow path through which a refrigerant flows is known (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even with the prior art such as Patent Document 1, there is still room for improvement in the technique for improving the temperature distribution on the placement surface of the plate-like member in the holding device.

[0005] An object of the present invention is to provide a technique for improving the temperature distribution on the placement surface of a plate-like member in a holding device.

Means for Solving the Problems

[0006] The present invention has been made to solve at least a part of the above problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a holding device is provided. The holding device is a plate-shaped member having a pair of main surfaces, the plate-shaped member having a mounting surface formed on one of the pair of main surfaces on which an object is placed, a flow path disposed inside the plate-shaped member through which a refrigerant flows, and a hole formed along a direction intersecting each of the pair of main surfaces, wherein the flow path includes a branching section that branches the flow path into two branched flow paths, and a merging section that merges the two branched flow paths into one, and there is no hole between the two branched flow paths.

[0008] According to this configuration, the refrigerant flow path of the plate-shaped member includes a branching section that divides the flow path into two branched flow paths, and a merging section that merges the two branched flow paths into one. As a result, the refrigerant flowing through one flow path branches into two branched flow paths, then merges back into a single flow path. This allows for a larger cooling area compared to, for example, the case where the refrigerant flows through only one flow path. Therefore, the degree of cooling in each part of the plate-shaped member can be adjusted, thereby improving the temperature distribution on the mounting surface of the plate-shaped member.

[0009] (2) In the holding device of the above form, the flow path may have a plurality of branching and merging sections. With this configuration, the number of branching and merging sections can be increased or decreased using information on the temperature distribution of the plate-shaped member obtained, for example, by simulation or experiment. Therefore, the temperature distribution on the mounting surface of the plate-shaped member can be further improved.

[0010] (3) In the holding device of the above form, in a cross section perpendicular to the central axis of the plate-shaped member, including the flow path, the distance between the two branched flow paths included in the first branched confluence of the plurality of branched confluences may be greater than the distance between the two branched flow paths included in the second branched confluence of the plurality of branched confluences. With this configuration, the distance between the two branched flow paths included in the first branched confluence and the second branched confluence of the plurality of branched confluences is different. This makes it possible to adjust the degree of cooling at each part of the plate-shaped member by making the distance between the two branched flow paths different, for example, using information on the temperature distribution of the plate-shaped member. Therefore, the temperature distribution on the mounting surface of the plate-shaped member can be further improved.

[0011] (4) In the above-described holding device, in a cross section perpendicular to the central axis of the plate-shaped member, including the flow path, each of the two branched flow paths may be formed to curve away from each other. With this configuration, each of the two branched flow paths included in the branched merging section is formed to curve away from each other. This makes it possible to further enlarge the area that is cooled to a relatively large degree by the refrigerant, and thus further improve the temperature distribution on the mounting surface of the plate-shaped member.

[0012] (5) In the above-described holding device, in a cross section perpendicular to the central axis of the plate-shaped member, including the flow path, one of the two branched flow paths may be formed to conform to the shape of the flow path, and the other of the two branched flow paths may be formed to curve away from the first branched flow path. With this configuration, one of the two branched flow paths included in the branched merging section is formed to conform to the shape of the flow path, while the other branched flow path is formed to curve away from the first branched flow path. This makes it possible to add a range cooled by a relatively small amount of refrigerant flowing through the other branched flow path to the range cooled by the refrigerant flowing through the first branched flow path, which allows a relatively large amount of refrigerant to flow easily. Therefore, the degree of freedom in adjusting the degree of cooling in each part of the plate-shaped member is improved, and the temperature distribution on the mounting surface of the plate-shaped member can be further improved.

[0013] (6) In the above-described holding device, the width of one branch channel may be greater than the width of the other branch channel. With this configuration, a smaller amount of refrigerant flows through the other branch channel than through the one branch channel. This allows the other branch channel to have a shape with a relatively large curve, for example, so that refrigerant can flow even in places where it is difficult to form a branch channel. Therefore, the area that is cooled to a relatively large degree by the refrigerant can be further enlarged, and the temperature distribution on the mounting surface of the plate-shaped member can be further improved.

[0014] (7) In the holding device of the above form, in a cross section perpendicular to the central axis of the plate-shaped member including the flow path, the first branch-junction of the plurality of branch-junctions is formed such that each of the two branch-flow paths is curved away from each other, and the second branch-junction of the plurality of branch-junctions is formed such that one of the two branch-flow paths follows the shape of the flow path, and the other branch-flow path is formed such that it is curved away from the first branch-flow path, and the second branch-junction may be located on the outer circumference side of the plate-shaped member than the first branch-junction. With this configuration, the other branch-flow path included in the second branch-junction can be formed even in a location where it is difficult to form the two branch-flow paths included in the first branch-junction. As a result, the second branch-junction can be located on the outer circumference side of the plate-shaped member, where there are often constraints on the formation of the flow path due to the shape of the plate-shaped member or the position of holes formed in the base. Therefore, even in areas where it is relatively difficult to form a flow path, the range where the degree of cooling by the refrigerant is relatively high can be included, thereby further improving the temperature distribution on the mounting surface of the plate-shaped member.

[0015] (8) In the above-described holding device, in a cross section perpendicular to the central axis of the plate-shaped member, including the flow path, the width of one of the two branched flow paths included in the branched confluence section may be greater than the width of the other branched flow path. With this configuration, less refrigerant flows through the other branched flow path than through the first branched flow path. In this way, the flow rate of the refrigerant can be adjusted by changing the width of the branched flow paths, and the degree to which the plate-shaped member is cooled by the refrigerant can be locally changed. Therefore, the temperature distribution on the mounting surface of the plate-shaped member can be further improved.

[0016] (9) In the holding device of the above-described embodiment, the branch and confluence portion may be disposed on the outer peripheral side of the plate-like member. According to this configuration, the branch and confluence portion is disposed on the outer peripheral side of the plate-like member, where there are often restrictions on the formation of the flow path. Thus, when an object is placed on the placement surface, the outer peripheral side of the plate-like member corresponding to the outer peripheral side of the object, which is likely to become relatively hot, can be cooled by the refrigerant flowing through the branch and confluence portion. Therefore, the temperature distribution of the object can be controlled.

[0017] Note that the present invention can be realized in various forms. For example, it can be realized in the form of a manufacturing method of the holding device, a system including the holding device, a control method of these devices and systems, a computer program for executing the processing of an object in these devices and systems, a server device for distributing the computer program, a non-transitory storage medium storing the computer program, and the like.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view of the holding device of the first embodiment. [Figure 2] It is a first cross-sectional view of the holding device of the first embodiment. [Figure 3] It is a second cross-sectional view of the holding device of the first embodiment. [Figure 4] It is an enlarged view of part B in FIG. 3. [Figure 5] It is a diagram for explaining a method of creating the center line of the flow path. [Figure 6] It is an enlarged view of part C in FIG. 3. [Figure 7] It is an enlarged view of part D in FIG. 3. [Figure 8] It is an enlarged view of part E in FIG. 3. [Figure 9] It is a cross-sectional view of the holding device of the second embodiment. [Figure 10] It is an enlarged view of part F in FIG. 9.

Embodiments for Carrying Out the Invention

[0019] <First Embodiment> Figure 1 is a perspective view of the holding device 1 of this embodiment. Figure 2 is a first cross-sectional view of the holding device 1 of this embodiment. The holding device 1 of this embodiment is an electrostatic chuck that holds a substrate W by electrostatic attraction. The electrostatic chuck is used, for example, as a table on which to place the substrate W in an etching process using plasma in a chamber equipped with the electrostatic chuck. The holding device 1 of this embodiment comprises a base 10, a ceramic substrate 20, and a joint (not shown). In the holding device 1, as shown in Figure 1, the base 10 and the ceramic substrate 20 are stacked in that order. The holding device 1 positions the substrate W relative to the holding device 1 by using a focus ring FR installed on the outer circumference of the ceramic substrate 20. In Figures 1 and 2, for convenience, the stacking direction of the base 10 and the ceramic substrate 20 is shown as the z-axis direction, the direction perpendicular to the z-axis is shown as the x-axis direction, and the direction perpendicular to the z-axis and x-axis is shown as the y-axis direction. For the sake of explanation, the size relationships of the base 10, ceramic substrate 20, substrate W, and focus ring FR shown in Figures 1 and 2 differ from the actual relationships.

[0020] The base 10 is a sintered body mainly composed of silicon carbide (SiC), and is a roughly cylindrical member that forms the base of the holding device 1. Here, "main component" means the component with the highest proportion. The material forming the base 10 is not limited to a material mainly composed of silicon carbide. The base 10 may be formed from materials such as aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W), alloys thereof, SUS, composites of metals and ceramics such as Al-SiC, or materials mainly composed of ceramics such as aluminum nitride (AlN) or alumina (Al2O3).

[0021] The base 10 comprises a first base 11 and a second base 12. The first base 11 and the second base 12 are joined together by an adhesive layer (not shown). The base 10 is not limited to a two-layer structure like the first base 11 and the second base 12; it may also be a single-layer structure or a structure consisting of three or more layers.

[0022] As shown in Figure 2, the first base 11 is located on the most negative side in the z-axis direction in the holding device 1. The first base 11 is a substantially circular plate-like member and has a pair of main surfaces 11a and 11b. On one of the pair of main surfaces 11a and 11b, the first base 11 has an inlet (not shown) for the refrigerant flowing through the flow path 30 (described later) to flow into the flow path 30, and an outlet (not shown) for the refrigerant to flow out of the flow path 30.

[0023] The second base 12 is stacked on the first base 11 on the positive side in the z-axis direction of the first base 11. The second base 12 is a substantially circular plate-like member of approximately the same size as the first base 11 and has a pair of main surfaces 12a and 12b. Of the pair of main surfaces 12a and 12b of the second base 12, a groove 13 is formed on the main surface 12b on the negative side in the z-axis direction, which serves as a flow path 30 through which the refrigerant flows. When the first base 11 and the second base 12 are joined together, the groove 13 formed in the second base 12 becomes a flow path 30 when the first base 11 acts as a cover for the groove 13. The base 10 has a plurality of holes 14 formed along the z-axis direction of the holding device 1. The detailed shape of the flow path 30 will be described later.

[0024] The ceramic substrate 20 is a plate-shaped member positioned on the positive side of the z-axis direction of the base 10. The ceramic substrate 20 is mainly composed of ceramics. In this embodiment, the ceramic substrate 20 is formed from a material mainly composed of aluminum oxide. However, the ceramic substrate 20 may also be formed from other ceramics such as aluminum nitride or silicon carbide. The ceramic substrate 20 has a pair of main surfaces 20a and 20b.

[0025] The ceramic substrate 20 has a mounting surface 21 formed on one of its pair of main surfaces 20a, 20b, that is opposite to the base 10, on which the substrate W is placed. A mounting surface 22 for the focus ring FR is formed on the outer circumference of the other main surface 20a of the ceramic substrate 20. The other main surface 20b of the pair of main surfaces 20a, 20b of the ceramic substrate 20 is joined to the second base 12 by a joint (not shown). The ceramic substrate 20 has holes 23 that communicate with each of the multiple holes 14 formed in the base 10. The method of joining the base 10 and the ceramic substrate 20 is exemplified by, but is not limited to, metal joining, resin joining, or joining with inorganic materials.

[0026] The ceramic substrate 20 of this embodiment has electrodes 24. The electrodes 24 are located inside the ceramic substrate 20. The electrodes 24 are formed of a conductive material such as tungsten or molybdenum. The electrodes 24 are connected to an external power source via electrode terminals (not shown) inserted through holes 14 and 23. Examples of electrodes 24 include high-frequency electrodes, chuck electrodes, and heater electrodes.

[0027] The holding device 1 of this embodiment has a hole 5a that penetrates the joint 5, which is made up of the base 10 and the ceramic substrate 20, in the z-axis direction through a hole 14 formed in the base 10 and a hole 23 formed in the ceramic substrate 20. The hole 5a in the joint 5 is used as a terminal hole for inserting a power supply terminal (not shown) for supplying power to an electrode 24 on the ceramic substrate 20, a gas hole for supplying helium gas to the back surface of the substrate W, a lift pin hole for inserting a lift pin (not shown) for lifting the substrate W from the ceramic substrate 20, a sensor hole for inserting a temperature sensor (not shown) for measuring the temperature of the mounting surface 21, and so on. In this embodiment, the hole 5a in the joint 5 penetrates the joint 5 in the z-axis direction, but it does not have to penetrate the joint 5. Specifically, the hole 5a may be a combination of, for example, a hole 14 that penetrates the base 10 and a hole having a bottom surface formed on the other main surface 20b of the ceramic substrate 20, or on the other main surface 20b. In this case, the other main surface 20b of the ceramic substrate 20, or the bottom surface formed on the other main surface 20b, becomes the bottom surface of the hole 5a. Alternatively, the hole 14 may be a non-through hole with a bottom surface. The joined body 5 corresponds to the "plate-like member" in the claims.

[0028] Next, the detailed shape of the flow path 30 will be described. The flow path 30 has a plurality of branching and merging sections 31 and 32. Each of the plurality of branching and merging sections 31 and 32 has a branching section that branches the flow path 30 into two branching flow paths, and a merging section that merges the two branching flow paths that were branched by the branching section into one. In the holding device 1 of this embodiment, there is no hole 14 between the two branching flow paths included in each of the plurality of branching and merging sections 31 and 32.

[0029] Figure 3 is a second cross-sectional view of the holding device 1. Figure 3 is a cross-sectional view taken along line AA in Figure 2, and specifically, it is a cross-sectional view perpendicular to the central axis C5 of the joint 5 on the second base 12 where the groove 13 is formed. As shown in Figure 3, the flow path 30 in this embodiment is formed in a substantially spiral shape. The flow path 30 has a flow path inlet 30a for refrigerant from the outside to flow into the flow path 30, and a flow path outlet 30b for refrigerant that has flowed through the flow path 30 to flow out of the flow path 30. That is, in the holding device 1 of this embodiment, the refrigerant flows into the flow path 30 from near the central axis C5 of the joint 5, flows counterclockwise toward the outer circumference of the base 10, and is discharged to the outside of the base 10 from the flow path outlet 30b.

[0030] Figure 4 is an enlarged view of section B in Figure 3, and is an enlarged cross-sectional view including branching and merging section 31, one of the multiple branching and merging sections 31, 32. The branching and merging section 31 shown in Figure 4 has a branching section 313 that branches the flow path 30 into two branching flow paths 311 and 312, and a merging section 314 that merges the two branching flow paths 311 and 312, which were branched by the branching section 313, into one. In the branching and merging section 31, as shown in Figure 4, no holes 14 are formed in the island-shaped section 315 sandwiched between the two branching flow paths 311 and 312.

[0031] The branching and merging section 31 is formed such that, in a cross-section perpendicular to the central axis C5 of the joint 5, which includes the flow path 30 as shown in Figure 4, each of the two branching flow paths 311 and 312 curves away from each other. Specifically, using the center line C30 of the flow path 30 shown in Figure 4, each of the multiple branching flow paths 311 and 312 is formed so as not to include the center line C30 of the flow path 30. The branching flow path 311 is formed to bulge inward from the joint 5 in the direction of the central axis C5 of the joint 5, as viewed from the center line C30 of the flow path 30. The branching flow path 312 is formed to bulge outward from the joint 5 in the direction away from the central axis C5 of the joint 5, as viewed from the center line C30 of the flow path 30. As a result, the island-shaped portion 315, sandwiched between the two branched channels 311 and 312, becomes a part that is cooled to a relatively large extent by the refrigerant flowing through each of the branched channels 311 and 312, thus increasing the area that is cooled to a relatively large extent by the refrigerant.

[0032] Figure 5 illustrates the method for creating the centerline of a flow path. Here, the method for creating the centerline of a flow path in this embodiment will be explained. In the method for creating the centerline of a flow path in this embodiment, first, multiple virtual lines are created passing through points on the central axis in a cross section perpendicular to the central axis of the member in which the flow path is formed. Specifically, as shown in Figure 5, multiple virtual lines L1, L2, L3, L4, L5, L6, L7 are created passing through points on the central axis C5 in a cross section perpendicular to the central axis C5 of the joint 5 which has a substantially circular shape. Each of the multiple virtual lines L1, L2, L3, L4, L5, L6, L7 can be set such that, for example, the angle between adjacent virtual lines on the central axis C5 differs by 1 degree, thereby creating virtual lines at regular intervals. Note that if the cross-sectional shape of the member in which the flow path is formed is polygonal, multiple virtual lines may be created using a line passing through the centroid of the polygon as the central axis.

[0033] Next, the intersection points of the virtual straight line and the outline of the flow path are determined in a cross section perpendicular to the central axis of the member in which the flow path is formed. Specifically, as shown in Figure 5, for example, intersection points P1a and P1b are determined as the intersection points of the virtual straight line L1 and the outline of the flow path 30. If the virtual straight line intersects each of the two branched flow paths, the intersection point closest to the central axis and the intersection point furthest from the central axis are determined as the intersection points of the virtual straight line and the outline of the flow path. Specifically, in the case of the virtual straight line L3 shown in Figure 5, of the branched flow paths 311 and 312, the intersection point between the outline Li311 on the opposite side of branched flow path 312 of branched flow path 311, which is closer to the central axis C5, is set as intersection point P3a, and the intersection point between the outline Lo312 on the opposite side of branched flow path 311 of branched flow path 312, which is farther from the central axis C5, is set as intersection point P3b. This determination of intersections is performed for each of the virtual lines L1, L2, L3, L4, L5, L6, and L7 that pass through the area including the branching and merging section 31, and the intersections P1a and P1b on the virtual line L1, P2a and P2b on the virtual line L2, P3a and P3b on the virtual line L3, P4a and P4b on the virtual line L4, P5a and P5b on the virtual line L5, P6a and P6b on the virtual line L6, and P7a and Pb on the virtual line L7 are determined.

[0034] Next, we determine the midpoint at the intersection of two points on a single virtual straight line. Specifically, in the case of the virtual straight line L1 shown in Figure 5, the midpoint P1m is defined as a point on the virtual straight line L1 that is the same distance from both intersection point Pa1 and intersection point Pa2. For each of the virtual straight lines L2, L3, L4, L5, L6, and L7, we determine the midpoints P2m, P3m, P4m, P5m, P6m, and P7m in the same manner. Finally, we determine the centerline of the flow path by connecting multiple midpoints. In Figure 5, the dashed line connecting the midpoints P1m, P2m, P3m, P4m, P5m, P6m, and P7m represents the centerline C30 of the flow path 30. In the explanation using Figure 5, to avoid making the diagram complicated, the intermediate points P1m, P2m, P3m, P4m, P5m, P6m, and P7m are discretely determined by setting virtual straight lines L1, L2, L3, L4, L5, L6, and L7 at certain intervals. Therefore, the shape of the center line C30 between adjacent intermediate points is such that the intermediate points P1m, P2m, P3m, P4m, P5m, P6m, and P7m are smoothly connected. However, the method of connecting the intermediate points is not limited to this. Adjacent intermediate points may be connected by straight lines. Alternatively, intermediate points may be determined continuously by reducing the angle between the central axes of adjacent virtual straight lines, and then adjacent intermediate points may be connected. Furthermore, the method of creating the center line of the flow path is not limited to this.

[0035] In the branching and merging section 31, in a cross-section perpendicular to the central axis C5 of the joint 5, the width of branch channel 312, one of the two branch channels 311 and 312 included in the branching and merging section 31, is greater than the width of branch channel 311. In this way, the widths of the two branch channels 311 and 312 can be made different in the branching and merging section 31. This allows for adjustment of the refrigerant flow and changes the degree of cooling by the refrigerant. Note that the widths of branch channel 311 and branch channel 312 may be the same.

[0036] Figure 6 is an enlarged view of section C in Figure 3, and is an enlarged cross-sectional view including branching and merging section 32, one of the multiple branching and merging sections 31 and 32. The branching and merging section 32 shown in Figure 6 has a branching section 323 that branches the flow path 30 into two branching flow paths 321 and 322, and a merging section 324 that merges the two branching flow paths 321 and 322, which were branched by the branching section 323, into one. In the branching and merging section 32, as shown in Figure 6, no holes 14 are formed in the island-shaped section 325 sandwiched between the two branching flow paths 321 and 322. Branching flow path 321 corresponds to "one branching flow path" in the claims, and branching flow path 322 corresponds to "the other branching flow path" in the claims.

[0037] In the branched confluence section 32, in a cross-section perpendicular to the central axis C5 of the joint 5 including the flow path 30 as shown in Figure 6, branched flow path 321 of the two branched flow paths 321 and 322 is formed to follow the shape of flow path 30, while branched flow path 322 of the two branched flow paths 321 and 322 is formed to curve away from branched flow path 321. Specifically, branched flow path 321 is formed to be straighter than branched flow path 322 and has a less pronounced curve than branched flow path 322. More specifically, using the center line C30 of flow path 30 shown in Figure 6, branched flow path 321 is formed to include the center line C30 of flow path 30. On the other hand, branched flow path 322 is formed not to include the center line C30 of flow path 30, and is formed to bulge outward from the joint 5 in the direction away from the central axis C5 of the joint 5 when viewed from the center line C30 of flow path 30. Furthermore, the branch channel 321 has a shape that gently connects the channel 30 upstream of the branch section 323 and the channel 30 downstream of the confluence section 324. On the other hand, the branch channel 322 is formed such that the distance to the center line C30 increases as it moves away from the branch section 323 and decreases as it approaches the confluence section 324. The island-shaped section 325 sandwiched between the branch channel 321 and the branch channel 322, which have such shapes, is a part that is cooled to a relatively large extent by the refrigerant flowing through each of the branch channels 321 and 322, thus making it possible to enlarge the area that is cooled to a relatively large extent by the refrigerant.

[0038] In the branching and merging section 32 shown in Figure 6, the width of the branched channel 321, which is formed to conform to the shape of the channel 30, is greater than the width of the branched channel 322. As a result, most of the refrigerant flowing in the channel 30 flows through the branched channel 321, and a relatively small amount of refrigerant flows through the branched channel 322. Therefore, even if the shape of the branched channel 322 is made less curved, the pressure loss of the refrigerant flow in the channel 30 does not increase significantly. Consequently, the branching and merging section 32, including the branched channel 322, is easily positioned on the outer periphery of the joint 5, where there are often constraints on the formation of the channel 30, such as the shape of the base 10 and the position of the holes 14 formed in the base 10. Furthermore, the orientation flat portion of the substrate W, which is placed on the mounting surface 21, is located on the outside of the joint 5. The orientation flat portion of the substrate W often does not come into contact with the ceramic substrate 20, so its temperature tends to rise. However, by positioning the branching and merging section 32, including the branched channel 322, on the outer periphery of the joint 5, the orientation flat portion of the substrate W can be efficiently cooled. Because the branching and merging section 32 has these characteristics, most of the branching and merging sections 32 are located on the outer circumference side of the holding device 1, compared to the branching and merging sections 31 (see Figure 3).

[0039] The holding device 1 of this embodiment has a plurality of branching and merging sections 31 and a plurality of branching and merging sections 32. In a cross section perpendicular to the central axis C5 of the joint 5, including the flow path 30, as shown in Figure 3, the distance between the two branching flow paths 311 and 312 included in the first branching and merging section 31 of the plurality of branching and merging sections 31 is greater than the distance between the two branching flow paths 311 and 312 included in the second branching and merging section 31 of the plurality of branching and merging sections 31. The distance between the two branching flow paths 321 and 322 included in the first branching and merging section 32 of the plurality of branching and merging sections 32 is greater than the distance between the two branching flow paths 321 and 322 included in the second branching and merging section 32 of the plurality of branching and merging sections 32.

[0040] Figure 7 is an enlarged view of section D in Figure 3, and is an enlarged cross-sectional view including two branching and merging sections 31a and 31b of the multiple branching and merging sections 31 that the flow path 30 has. Figure 7 shows the centerline C30 of the flow path 30 as explained using Figure 5. As shown in Figure 7, the size of the island-like section 315 sandwiched between the two branching and merging sections 311 and 312 included in branching and merging section 31a is larger than the size of the island-like section 315 sandwiched between the two branching and merging sections 311 and 312 included in branching and merging section 31b. Specifically, if the length of the longest line segment that is perpendicular to the center line C30 of the flow path 30 and connects the outline Lo311 of the branch flow path 311 on the branch flow path 312 side with the outline Li312 of the branch flow path 312 on the branch flow path 311 side is taken as the distance between the two branch flow paths 311 and 312, then the distance L31a between the two branch flow paths 311 and 312 included in the branch merging section 31a is greater than the distance L31b between the two branch flow paths 311 and 312 included in the branch merging section 31b.

[0041] Figure 8 is an enlarged view of section E in Figure 3, and is an enlarged cross-sectional view including two of the multiple branching and merging sections 32a and 32b of the flow path 30. Figure 8 shows the centerline C30 of the flow path 30 as explained using Figure 5. In addition, Figure 8 shows the centerline C30a of the flow path 30 in branching and merging section 32a and the centerline C30b of the flow path 30 in branching and merging section 32b. As shown in Figure 8, the size of the island-like section 325 sandwiched between the two branching flow paths 321 and 322 included in branching and merging section 32a is smaller than the size of the island-like section 325 sandwiched between the two branching flow paths 321 and 322 included in branching and merging section 32b. Specifically, for the branching and merging section 32a, the length of the longest line segment that is perpendicular to the center line C30a of the flow path 30 and connects the outline Lo321 of the branching flow path 321 on the branching flow path 322 side with the outline Li322 of the branching flow path 322 on the branching flow path 321 side with the longest line segment that is perpendicular to the center line C30b of the flow path 30 and connects the outline Li321 of the branching flow path 321 on the branching flow path 322 side with the longest line segment that is perpendicular to the center line C30b of the flow path 30 and connects the outline Lo322 of the branching flow path 322 on the branching flow path 321 side with the longest line segment that is perpendicular to the center line C30b of the flow path 30 and connects the outline Li321 of the branching flow path 321 on the branching flow path 322 side with the longest line segment that is perpendicular to the center line C30b of the flow path 30 and connects the longest line segment that is perpendicular to the outline Lo322 of the branching flow path 322 on the branching flow path 321 side with the longest line segment that is perpendicular to the center line C30b of the flow path 30. In this case, the distance L32a between the two branch channels 321 and 322 included in the branching / merging section 32a is smaller than the distance L32b between the two branch channels 311 and 312 included in the branching / merging section 32b.

[0042] As shown in Figures 7 and 8, even in branching and merging sections with similar configurations, the size of the area cooled by the refrigerant can be changed by varying the distance between the two branching channels. Similarly, the relationship between the distance between the two branching channels 311 and 312 in branching and merging section 31 and the distance between the two branching channels 321 and 322 in branching and merging section 32 allows for a change in the size of the area cooled by the refrigerant by varying the distance between the two branching channels.

[0043] As described above, according to the holding device 1 of this embodiment, the flow path 30 through which the refrigerant flows in the joint 5 includes a branching and merging section 31 having a branching section 313 that branches the flow path 30 into two branched flow paths 311 and 312, and a merging section 314 that merges the two branched flow paths 311 and 312 into one, and a branching and merging section 32 having a branching section 323 that branches the flow path 30 into two branched flow paths 321 and 322, and a merging section 324 that merges the two branched flow paths 321 and 322 into one. As a result, the refrigerant flowing through one flow path 30 branches into two branched flow paths 311 and 312, or two branched flow paths 321 and 322, and then merges and flows through one flow path 30 again. Therefore, compared to, for example, the case where the refrigerant flows through only one flow path, the area that is cooled can be increased. Therefore, since the degree of cooling in each part of the joint 5 can be adjusted, the temperature distribution on the mounting surface 21 of the joint 5 can be improved.

[0044] Furthermore, the holding device 1 of this embodiment allows for adjustment of the degree of cooling on the mounting surface 21 of the bonded body 5. This improves the uniformity of heat dissipation of the substrate W placed on the mounting surface 21 in a plasma-based process.

[0045] Furthermore, according to the holding device 1 of this embodiment, the number of branching and merging sections 31 and 32 can be increased or decreased using information on the temperature distribution of the jointed body 5, obtained, for example, through simulations or experiments. Therefore, the temperature distribution on the mounting surface 21 of the jointed body 5 can be further improved.

[0046] Furthermore, according to the holding device 1 of this embodiment, the distance between the two branch channels 311 and 312 included in branch channel 31 of the multiple branch channels 31 and 32 is greater than the distance between the two branch channels 321 and 322 included in branch channel 32 of the multiple branch channels 31 and 32. This allows the degree of cooling at each part of the joint 5 to be adjusted by varying the size of the branch channels 31 and 32 using information on the temperature distribution of the joint 5. Therefore, the temperature distribution on the mounting surface 21 of the joint 5 can be further improved.

[0047] Furthermore, according to the holding device 1 of this embodiment, each of the two branched channels 311 and 312 included in the branched confluence section 31 is formed to curve in a direction away from each other. This makes it possible to enlarge the area that is cooled to a relatively large degree by the refrigerant, thereby further improving the temperature distribution on the mounting surface 21 of the assembled body 5.

[0048] Furthermore, according to the holding device 1 of this embodiment, of the two branched flow paths 321 and 322 included in the branched confluence section 32, branched flow path 321 is formed to conform to the shape of the flow path 30, while branched flow path 322 is formed to curve away from branched flow path 321. This makes it possible to add a region cooled by a relatively small amount of refrigerant flowing through branched flow path 322 to the region cooled by the refrigerant flowing through branched flow path 321, which allows a relatively large amount of refrigerant to flow easily. Therefore, the degree of freedom in adjusting the degree of cooling in each part of the jointed body 5 is improved, and the temperature distribution on the mounting surface 21 of the jointed body 5 can be further improved.

[0049] Furthermore, according to the holding device 1 of this embodiment, in the branching and merging section 32, the width of the branching channel 321 is greater than the width of the branching channel 322, so less refrigerant flows through the branching channel 322 than through the branching channel 321. As a result, by making the branching channel 322 a shape with a relatively large bend, that is, a shape with a sharp bend and small curvature, the refrigerant can flow even in places where it is difficult to form a branching channel without significantly increasing the pressure loss of the refrigerant. Therefore, the area that is cooled to a relatively large degree by the refrigerant can be further enlarged, and the temperature distribution on the mounting surface 21 of the jointed body 5 can be further improved.

[0050] Furthermore, according to the holding device 1 of this embodiment, the branched channel 322 included in the branched confluence section 32 can be formed even in locations where it is difficult to form the two branched channels 311 and 312 included in the branched confluence section 31. As a result, the branched confluence section 32 can be positioned on the outer periphery of the jointed body 5, relatively close to the orientation flat portion of the substrate W, where there are often constraints on the formation of the channel 30 due to the shape of the jointed body 5 or the position of the hole 14 formed in the base 10, and where it often does not come into contact with the ceramic substrate 20. In this way, even in locations where it is relatively difficult to form the channel 30 and where the thermal conditions are severe, the branched confluence section 32 can be formed to include the area where the degree of cooling by the refrigerant is relatively large. Therefore, the temperature distribution on the mounting surface 21 of the jointed body 5 can be further improved.

[0051] Furthermore, according to the holding device 1 of this embodiment, the branch channel 312 included in the branch junction 31 is narrower than the branch channel 311. As a result, less refrigerant flows through the branch channel 312 than through the branch channel 311. In this way, the flow rate of the refrigerant can be adjusted by changing the width of the branch channels 311 and 312, so that the degree to which the assembled body 5 is cooled by the refrigerant can be locally changed. Therefore, the temperature distribution on the mounting surface 21 of the assembled body 5 can be further improved.

[0052] Furthermore, according to the holding device 1 of this embodiment, the branching and merging section 32 is positioned on the outer circumference of the joining body 5, where there are often constraints on the formation of the flow path 30. As a result, when the substrate W is placed on the mounting surface 21, the outer circumference of the joining body 5, which corresponds to the outer circumference of the substrate W and tends to become relatively hot, can be cooled by the coolant flowing through the branching and merging section 32. Therefore, the temperature distribution of the substrate W can be controlled.

[0053] <Second Embodiment> Figure 9 is a cross-sectional view of the holding device of the second embodiment. The holding device 2 of the second embodiment differs from the holding device 1 of the first embodiment (Figure 3) in that the flow path has three types of branching and merging sections.

[0054] The holding device 2 of the second embodiment comprises a base 10, a ceramic substrate 20, and a joint (not shown). The flow path 30 of the base 10 of the holding device 2 has a plurality of branching and merging sections 31, 32, in addition to a branching and merging section 33.

[0055] Figure 10 is an enlarged view of section F in Figure 9. The branching and merging section 33 shown in Figure 10 has a branching section 333 that branches the flow path 30 into two branching flow paths 331 and 332, and a merging section 334 that merges the two branching flow paths 331 and 332 branched by the branching section 333 into one. The branching and merging section 33 is formed to connect to each of the two branching and merging sections 31, and the two branching flow paths 331 and 332 are formed to be substantially parallel, as shown in Figure 10. As a result, the refrigerant that merges at the merging section 314 of the branching and merging section 31 flows through either of the two branching flow paths 331 or 332, thereby reducing the pressure loss of the refrigerant flowing through the flow path 30. There are no holes 14 in the island-shaped section 335 sandwiched between the two branching flow paths 331 and 332 included in the branching and merging section 33.

[0056] As described above, with the holding device 2 of this embodiment, the refrigerant flowing through one channel 30 branches into two branch channels 311, 312, or two branch channels 321, 322, and then merges back into one channel 30, thus allowing for a relatively large area to be cooled. Therefore, the degree of cooling at each part of the jointed body 5 can be adjusted, thereby improving the temperature distribution on the mounting surface 21 of the jointed body 5.

[0057] Furthermore, according to the holding device 2 of this embodiment, the branching and merging section 33 has two branching channels 331 and 332 arranged substantially parallel to each other so that the refrigerant that merges at the merging section 314 of the branching and merging section 31 located upstream of the branching and merging section 33 continues to flow in two separate paths even after they have merged. This makes it possible to reduce pressure loss at the merging section 314.

[0058] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.

[0059] [Example 1] In the above-described embodiment, the flow path 30 is assumed to have a plurality of branching and merging sections 31 and 32. The number of branching and merging sections in the flow path of the holding device is not limited to this; there may be only one. Furthermore, the flow path 30 is assumed to have branching and merging sections 31 and 32 with different configurations. The branching and merging sections in the flow path 30 may be either branching and merging section 31 or branching and merging section 32.

[0060] [Differentiation 2] In the above-described embodiment, the holes 14 and 23 formed in the holding device were assumed to penetrate the holding device, as shown in Figure 2. However, the holes 14 and 23 do not necessarily have to penetrate the base 10.

[0061] [Difference 3] In the above-described embodiment, for each of the multiple branched and merging sections included in the flow path 30 of the joint 5, the island-shaped section sandwiched between two branched flow paths was assumed to have no holes. However, some of the multiple branched and merging sections included in the flow path may have holes in the island-shaped section. For example, branched and merging sections with holes in the island-shaped section may be arranged on both sides of a branched and merging section without holes in the island-shaped section. In a joint, the area with a hole tends to become a temperature singularity, so the flow path is formed to surround the hole. On the other hand, as in the above-described embodiment, even in the area without holes, the temperature distribution on the mounting surface of the joint can be adjusted by dividing one flow path into two branched flow paths with a branched and merging section.

[0062] [Differentiation Example 4] In the above-described embodiment, the branching and merging section 31 was assumed to be formed such that each of the two branched channels 311 and 312 curves away from each other. In the branching and merging section 32, one of the two branched channels 321 and 322, branched channel 321 is formed to follow the shape of the channel 30, and branched channel 322 is formed to curve away from branched channel 321. The configuration of the branching and merging section is not limited to this. For example, both branched channels may be formed to curve in the same direction. It is sufficient to have a branching section that branches the channel 30 into two branched channels, and a merging section that merges the two branched channels into one.

[0063] [Difference 5] In the above-described embodiment, each of the two branch channels 311 and 312 included in the branch-to-confluence section 31 was assumed to have a shape that does not include the center line C30 of the channel 30, as explained with reference to Figure 5. The branch channel 321 included in the branch-to-confluence section 32 had a shape that included the center line C30 of the channel 30, and the branch channel 322 had a shape that did not include the center line C30 of the channel 30. The relationship between each of the branch channels 311, 312, 321, and 322 and the center line C30 of the channel 30 is not limited to these. For example, the branch channel 321 included in the branch-to-confluence section 32 may have a shape that does not include the center line C30 of the channel 30, and for example, the branch channel 321 may be curved on the same side as the branch channel 322 with respect to the center line C30 of the channel 30.

[0064] [Modification 6] In the above-described embodiment, the branching and merging section 32 is positioned on the outer periphery side of the joint 5 than the branching and merging section 31. Furthermore, the branching and merging section 32 is positioned on the outer periphery side of the joint 5. The positional relationship between the branching and merging section 31 and the branching and merging section 32 in the joint 5 is not limited to this.

[0065] [Difference 7] In the above-described embodiment, the holding device comprises a base, a ceramic substrate, and a joint. However, the configuration of the holding device is not limited to this. It may be a single plate-like member in which the portion corresponding to the base and the portion corresponding to the ceramic substrate are integrated. Furthermore, the portion corresponding to the joint may be omitted, and the member corresponding to the base and the member corresponding to the ceramic substrate may be joined by diffusion bonding.

[0066] [Differentiation 8] In the above-described embodiment, it was assumed that a groove 13, which serves as a flow path 30 for refrigerant, is formed on the negative z-axis side main surface 12b of the pair of main surfaces 12a and 12b of the second base 12 of the base 10. However, the location where the flow path 30 is formed on the base 10 is not limited to this. For example, a groove that serves as a flow path 30 may be formed on the positive z-axis side main surface 12a of the pair of main surfaces 12a and 12b of the second base 12.

[0067] [Modification 9] In the above-described embodiment, the electrode 24 is positioned inside the ceramic substrate 20. The electrode 24 may also be positioned on the base 10, or at the joint that connects the base 10 and the ceramic substrate 20.

[0068] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0069] <Application Example 1> A holding device, A plate-like member having a pair of main surfaces, comprising: a mounting surface formed on one of the pair of main surfaces on which an object is placed; a flow path disposed inside the plate-like member for the flow of a refrigerant; and holes formed along directions intersecting each of the pair of main surfaces, The flow path includes a branching section that branches the flow path into two branched flow paths, and a merging section that merges the two branched flow paths into one. The absence of the aforementioned hole between the two aforementioned branched channels is a characteristic feature. holding device. <Application Example 2> The holding device described in Application Example 1, The flow path is characterized by having a plurality of branching and merging sections. holding device. <Application Example 3> A holding device as described in Application Example 1 or Application Example 2, The distance between two branch channels included in the first branch / merging section among the plurality of branch / merging sections is greater than the distance between two branch channels included in the second branch / merging section among the plurality of branch / merging sections. holding device. <Application Example 4> A holding device described in any one of the examples from Application Example 1 to Application Example 3, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, Each of the two aforementioned branched channels is formed to curve away from each other, holding device. <Application Example 5> A holding device described in any one of Application Examples 1 to 4, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, One of the two branch channels is formed to conform to the shape of the channel. The other of the two branch channels is characterized by being formed to curve away from the first branch channel. holding device. <Application Example 6> A holding device described in any one of Application Examples 1 to 5. The width of one of the branch channels is larger than the width of the other branch channel. holding device. <Application Example 7> A holding device described in any one of the examples from Application Example 1 to Application Example 6, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, The first branch-to-confluence section among the multiple branch-to-confluence sections is formed such that each of the two branch channels curves away from each other. Of the multiple branching and merging sections, the second branching and merging section is, One of the two branch channels is formed to conform to the shape of the channel. The other of the two branch channels is formed to curve away from the first branch channel. The second branching and merging section is characterized in that it is located on the outer circumference side of the plate-shaped member than the first branching and merging section. holding device. <Application Example 8> A holding device described in any one of the examples from Application Example 1 to Application Example 7, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, The width of one of the two branch channels included in the branching and merging section is greater than the width of the other branch channel. holding device. <Application Example 9> A holding device described in any one of Application Examples 1 to 8, The branching and merging section is characterized by being located on the outer circumference side of the plate-shaped member. holding device. [Explanation of symbols]

[0070] 1,2...holding device 5…Zygote 10…Base 11a, 11b… Main surface (of the first base) 12a, 12b… Main surface (of the second base) 14, 23… holes 20…Ceramic base material 21… Mounting surface 30…flow channel 31, 31a, 31b, 32, 32a, 32b, 33... Branching and merging sections 311, 312, 321, 322, 331, 332… Branching channel 313,323,333… Branch section 314, 324, 334… Confluence 315,325,335...island

Claims

1. A holding device, A plate-like member having a pair of main surfaces, comprising: a mounting surface formed on one of the pair of main surfaces on which an object is placed; a flow path disposed inside the plate-like member for the flow of a refrigerant; and holes formed along directions intersecting each of the pair of main surfaces, The flow path includes a branching section that branches the flow path into two branched flow paths, and a merging section that merges the two branched flow paths into one. The absence of the aforementioned hole between the two aforementioned branched channels is a characteristic feature. holding device.

2. A holding device according to claim 1, The flow path is characterized by having a plurality of branching and merging sections. holding device.

3. A holding device according to claim 2, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, The distance between the two branch channels included in the first branch channel among the multiple branch channels is greater than the distance between the two branch channels included in the second branch channel among the multiple branch channels. holding device.

4. A holding device according to any one of claims 1 to 3, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, Each of the two aforementioned branched channels is formed to curve in a direction away from each other, holding device.

5. A holding device according to any one of claims 1 to 3, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, One of the two branch channels is formed to conform to the shape of the channel. The other of the two branch channels is characterized in that it is formed to curve away from the first branch channel. holding device.

6. A holding device according to claim 5, The width of one of the branch channels is larger than the width of the other branch channel. holding device.

7. A holding device according to claim 2 or claim 3, In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, The first branch-to-confluence section among the multiple branch-to-confluence sections is formed such that each of the two branch channels curves away from each other. Of the multiple branching and merging sections, the second branching and merging section is, One of the two branch channels is formed to conform to the shape of the channel. The other of the two branch channels is formed to curve away from the first branch channel. The second branching and merging section is characterized in that it is located on the outer circumference side of the plate-shaped member than the first branching and merging section. holding device.

8. A holding device according to any one of claims 1 to 3. In a cross-section perpendicular to the central axis of the plate-like member, including the aforementioned flow path, The width of one of the two branch channels included in the branching and merging section is greater than the width of the other branch channel. holding device.

9. A holding device according to any one of claims 1 to 3, The branching and merging section is characterized by being located on the outer circumference side of the plate-shaped member. holding device.

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