Holding device

Abstract

To provide a holding device capable of obtaining clear temperature distribution between an inner peripheral portion and an outer peripheral portion of the holding surface of a wafer.SOLUTION: A holding device includes a ceramic member 41 having a suction surface 51 and a lower surface 52 provided on the side opposite to the suction surface 51 in the Z-axis direction, and a base member 42 having an upper surface 61 and a lower surface 62 provided on the opposite side of the upper surface 61, and in an electrostatic chuck 10 in which the lower surface 52 of the ceramic member 41 and the upper surface 61 of the base member 42 are thermally connected to hold a wafer W on the surface of the suction surface 51 of the ceramic member 41, the base member 42 includes refrigerant flow paths 66 and 67 for flowing a refrigerant and an annular groove portion 63 when viewed from the Z-axis direction, and the ceramic member 41 has a heat insulating space 74 that is arranged so as to overlap the groove portion 63 when viewed from the Z-axis direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a holding device for holding an object. [Background technology]

[0002] As an example of prior art related to holding devices, Patent Document 1 discloses a plasma processing device in which concentric slits are provided in an electrode block to suppress heat transfer between the inner and outer periphery of the holding surface (wafer holding surface) of an object in order to control the inner and outer periphery to different temperatures and obtain a clear temperature distribution. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-243371 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above device cannot suppress the radial heat transfer inside the dielectric film (ceramics), so the temperature boundary (temperature difference) between the inner and outer peripheries of the holding surface of the object may become unclear due to the radial heat transfer inside the dielectric film, and a clear temperature distribution may not be obtained.

[0005] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a holding device that can obtain a clear temperature distribution between the inner and outer periphery of the holding surface of the object. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present disclosure is to A holding device comprising: a plate-shaped member having a first surface and a second surface provided on an opposite side to the first surface in a first direction; and a base member having a third surface and a fourth surface provided on the opposite side to the third surface, wherein the second surface of the plate-shaped member and the third surface of the base member are thermally connected, and the holding device holds an object on the first surface of the plate-shaped member, The base member is a refrigerant flow path for flowing a refrigerant; When viewed from the first direction Extending from the third surface toward the fourth surface and a first insulating portion having an annular shape. When viewed from the first direction, the plate-shaped member is To overlap The second insulation section is Inside Yes 、 The second insulating section is a gas tunnel having a gas supply port and a supply path extending from the supply port toward the second insulating section, and overlaps with 5% or more of the entire first insulating section when viewed from the first direction. It is characterized by:

[0007] In this holding device, when viewed from a first direction, a second insulating section is disposed on the plate-shaped member, so that heat transfer in the second direction (radial direction) within the plate-shaped member can be suppressed and heat transfer in the first direction can be promoted. In addition, in the base member, heat transfer in the second direction between the inner peripheral portion and the outer peripheral portion, with the first insulating section as a boundary, is suppressed. Furthermore, when viewed from the first direction, a second insulating section is disposed around the first insulating section, so that the temperature region formed by the base member is transferred in the first direction inside the plate-shaped member in almost the same state, so that a clear temperature distribution can be obtained between the inner peripheral portion and the outer peripheral portion on the first surface. Since the first heat insulating section and the second heat insulating section are arranged so as to overlap each other, and the second heat insulating section is arranged directly above the first heat insulating section, the inner and outer regions of the base member are almost the same as the inner and outer regions of the first surface. Therefore, the temperature regions controlled in the inner and outer regions of the base member are directly reflected in the first surface. Therefore, the controllability of the temperature distribution control in the first surface is further improved, and a clearer temperature distribution can be obtained between the inner and outer peripheral portions of the first surface.

[0008] In the above-mentioned holding device, A plurality of protrusions are formed on the first surface, The convex portion is preferably arranged so as not to overlap the first heat insulating portion when viewed from the first direction.

[0009] In this holding device, the protrusions come into contact with the object to hold it. Since the protrusions are not disposed directly above the first heat insulating part, the temperature distribution between the inner periphery and the outer periphery becomes clearer on the first surface (the surface in contact with the object). Furthermore, when comparing the heat transfer between the plate-shaped member and the object between the protrusions and the part directly above the first heat insulating part where the protrusions are not disposed, the part directly above the first heat insulating part where the protrusions are not disposed is less likely to transfer heat. As a result, the boundary where a temperature difference occurs between the inner periphery and the outer periphery of the plate-shaped member is clearly visible, and a clearer temperature distribution can be obtained between the inner periphery and the outer periphery on the first surface.

[0010] In the above-mentioned holding device, It is preferable that the second insulating portion is a groove formed on the first surface, or an internal cavity located on the first surface side of a position 1 / 3 of the thickness of the plate-shaped member from the second surface in the first direction.

[0011] In this way, by forming the second heat insulating portion as a groove formed in the first surface or an internal cavity located above 1 / 3 of the thickness, it is possible to effectively suppress heat transfer in the second direction (radial direction) in the vicinity of the first surface of the plate-shaped member. Therefore, heat transfer in the first direction is further promoted. Therefore, the temperatures controlled at the inner and outer periphery of the base member are transferred as they are inside the plate-shaped member in the first direction, and a clear temperature difference is generated between the inner and outer periphery on the first surface, so that a clearer temperature distribution can be obtained between the inner and outer periphery.

[0012] Furthermore, by forming the second heat insulating portion by a groove or an internal cavity, the second heat insulating portion can be provided very easily in the plate-like member. For example, by using a gas tunnel that has been conventionally formed in the plate-like member as the internal cavity, the second heat insulating portion can be provided in the plate-like member simply by changing the shape and arrangement of the gas tunnel.

[0013] In the above-mentioned holding device, The first surface of the plate-like member is An inner region located inside the second insulation section when viewed from the first direction, and an outer region located outside the second insulation section when viewed from the first direction, It is preferable that the coolant flow passage is provided independently with an inner coolant flow passage for cooling the inner region and an outer coolant flow passage for cooling the outer region.

[0014] In this way, the inner region and the outer region can be cooled by independent refrigerant flow paths, i.e., the inner refrigerant flow path and the outer refrigerant flow path are provided with separate passage inlets and passage outlets, and the temperature and flow speed of the refrigerant can be changed separately, and since the inner region and the outer region are separated by the first insulation part, the accuracy of temperature distribution control in the inner region and the outer region of the first surface can be further improved. Therefore, a clearer temperature distribution can be obtained between the inner peripheral portion and the outer peripheral portion of the first surface.

[0017] In the above-mentioned holding device, A plurality of protrusions are formed on the first surface, the second heat insulating portion is a groove formed on the first surface, or an internal cavity arranged on the first surface side of a position that is 1 / 3 of the thickness of the plate-like member from the second surface in the first direction, before It is preferable that the number of the protrusions is greater in the non-arrangement region of the internal cavity than in the arrangement region of the internal cavity when viewed from the first direction. Note that the comparison of the number of the protrusions may be made in terms of the number of the protrusions arranged per unit area.

[0018] By doing this, there are few (or no) protrusions in the placement area of ​​the internal cavity (which is also the placement area of ​​the first stage heating section), and many protrusions are placed in the non-placement area of ​​the internal cavity (which is also the non-placement area of ​​the first stage heating section). As a result, the contact area with the object is large in the area where many protrusions are placed, improving heat transfer and temperature controllability. Therefore, the control temperature can be precisely changed between the inner area and the outer area on the first surface, with the non-placement area of ​​the internal cavity as the boundary, and a clear temperature distribution can be obtained between the inner and outer periphery on the first surface. Effect of the Invention

[0019] According to the present disclosure, it is possible to provide a holding device that can obtain a clear temperature distribution between the inner and outer periphery of the holding surface of an object. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic perspective view of an electrostatic chuck according to a first embodiment. [Diagram 2] 1 is a schematic configuration diagram of an XZ cross section of an electrostatic chuck according to a first embodiment. [Diagram 3] 1 is a schematic configuration diagram of an electrostatic chuck according to a first embodiment in an XY plane. [Figure 4] FIG. 11 is a schematic configuration diagram of an electrostatic chuck according to a second embodiment of the present invention, taken along an XZ cross section. [Diagram 5] 10(A) to 10(E) are schematic configuration diagrams of an electrostatic chuck according to a second embodiment taken along an XY plane. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] [First embodiment] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A holding device according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In this embodiment, a case where the holding device is applied to an electrostatic chuck for holding a semiconductor wafer will be described.

[0022] <Overall structure of electrostatic chuck> The electrostatic chuck of this embodiment will be described with reference to Fig. 1 to Fig. 3. The electrostatic chuck 10 is a device that attracts and holds an object (e.g., a wafer W) by electrostatic attraction, and is used, for example, to fix the wafer W in a vacuum chamber of a semiconductor manufacturing device. As shown in Fig. 1, the electrostatic chuck 10 has a ceramic member 41 which is a plate-shaped member, a base member 42, a bonding layer 43, and the like.

[0023] For convenience of explanation, in the following description, the X, Y and Z axes are defined as shown in Fig. 1. Here, the Z axis is an axis in the direction of the central axis Ca of the electrostatic chuck 10 (the vertical direction in Fig. 1), and the X and Y axes are axes in the radial direction of the electrostatic chuck 10. The Z axis direction (i.e., the direction of the central axis Ca) is an example of a "first direction" in the present disclosure, and the X and Y axis directions (i.e., the radial direction of the electrostatic chuck 10) are an example of a "second direction" in the present disclosure.

[0024] The ceramic member 41 is, for example, a disk-shaped member, and is made of ceramics. Various ceramics can be used as the ceramic, but from the viewpoints of strength, wear resistance, plasma resistance, etc., it is preferable to use ceramics whose main component is, for example, aluminum oxide (alumina, Al2O3) or aluminum nitride (AlN). Note that the main component here means the component with the highest content (for example, a component with a volume content of 90 vol% or more).

[0025] The ceramic member 41 has a diameter of, for example, about 150 mm to 300 mm and a thickness of, for example, about 2 mm to 6 mm. The ceramic member 41 desirably has a thermal conductivity in the range of 10 to 50 W / mK (more preferably, 18 to 30 W / mK, for example, 20 W / mK).

[0026] 1 and 2, the ceramic member 41 has an adsorption surface 51 which is an upper surface, and a lower surface 52 which is provided on the opposite side to the adsorption surface 51 in the central axis direction (i.e., the Z-axis direction) of the ceramic member 41. The ceramic member 41 holds the wafer W on the adsorption surface 51. The adsorption surface 51 is an example of a "first surface" in the present disclosure, and the lower surface 52 is an example of a "second surface" in the present disclosure.

[0027] As shown in Figs. 2 and 3, the adsorption surface 51 has an annular convex portion 71 formed near its outer edge, and a plurality of independent columnar convex portions 72 are formed inside the annular convex portion 71. The annular convex portion 71 is also called a seal band. The cross section (XZ cross section) of the annular convex portion 71 has a substantially rectangular shape as shown in Fig. 2. The height (dimension in the Z-axis direction) of the annular convex portion 71 is, for example, about 10 µm to 20 µm. The width (dimension in the X-axis direction) of the annular convex portion 71 is, for example, about 0.5 mm to 5.0 mm.

[0028] As shown in FIG. 3, each of the protrusions 72 has a substantially circular shape when viewed in the Z-axis direction, and is disposed at substantially equal intervals. The cross-sectional shape (XZ cross-section) of each of the protrusions 72 is substantially rectangular, as shown in FIG. 2. The height of the protrusions 72 is substantially the same as the height of the annular protrusion 71, and is, for example, about 10 μm to 20 μm. The width of the protrusions 72 (maximum diameter of the protrusions 72 when viewed in the Z-axis direction) is, for example, about 0.5 mm to 1.5 mm. The portion of the adsorption surface 51 of the ceramic member 41 inside the annular protrusion 71 where the protrusions 72 are not formed is a recess 73.

[0029] The wafer W is supported by the annular convex portion 71 and the multiple convex portions 72 on the attracting surface 51 of the ceramic member 41 and is held by the electrostatic chuck 10. When the wafer W is held by the electrostatic chuck 10, a space exists between the surface (lower surface) of the wafer W and the attracting surface 51 (more specifically, the concave portion 73 of the attracting surface 51) of the ceramic member 41. An inert gas (e.g., helium gas) is supplied to this space.

[0030] The ceramic member 41 includes therein a chuck electrode (not shown) having, for example, a substantially circular shape as viewed in the Z-axis direction. The chuck electrode generates an electrostatic force when a voltage is applied from a power source (not shown), and the wafer W is attracted to and held on the attracting surface 51 by the electrostatic force.

[0031] 1, the base member 42 is cylindrical, more specifically, a stepped cylindrical shape formed by stacking two cylinders of different diameters with a common central axis Ca, with the lower surface of the cylinder with the smaller diameter placed on the upper surface of the cylinder with the larger diameter. The base member 42 is preferably made of a metal (e.g., aluminum, an aluminum alloy, etc.), but may be made of a material other than metal.

[0032] 1 and 2, the base member 42 has an upper surface 61 and a lower surface 62 provided on the opposite side to the upper surface 61 in the direction of the central axis Ca (see FIG. 2) of the base member 42 (ceramic member 41) (i.e., the Z-axis direction). The upper surface 61 is an example of a "third surface" in the present disclosure, and the lower surface 62 is an example of a "fourth surface" in the present disclosure.

[0033] The diameter of the base member 42 is, for example, about 150 mm to 300 mm at the upper stage and about 180 mm to 350 mm at the lower stage. The thickness (dimension in the Z-axis direction) of the base member 42 is, for example, about 20 mm to 50 mm. The thermal conductivity of the base member 42 (assumed to be aluminum) is greater than that of the ceramic member 41, and is desirably within the range of 180 to 250 W / mK (preferably, about 230 W / mK).

[0034] The base member 42 is joined to the ceramic member 41 by a joining layer 43 disposed between a lower surface 52 of the ceramic member 41 and an upper surface 61 of the base member 42. The joining layer 43 is made of an adhesive material such as a silicone resin, an acrylic resin, or an epoxy resin. The thickness (dimension in the Z-axis direction) of the joining layer 43 is, for example, about 0.1 mm to 1.0 mm. The thermal conductivity of the joining layer 43 is, for example, 1.0 W / mK. The thermal conductivity of the joining layer 43 (assumed to be a silicone resin) is desirably within a range of 0.1 to 2.0 W / mK (preferably, 0.5 to 1.5 W / mK).

[0035] As shown in Fig. 2, the base member 42 is provided with a groove portion 63 that extends from an upper surface 61 at a substantially radially central position toward the lower surface 52 along the central axis Ca (see Fig. 2) (i.e., the Z-axis). Moreover, as shown in Fig. 3, the groove portion 63 extends in an annular shape centered on the central axis Ca of the base member 42. Therefore, the base member 42 is divided by the groove portion 63 into an inner region 64 located inside the groove portion 63 and an outer region 65 located outside the groove portion 63.

[0036] Moreover, the depth of the groove 63, that is, the length from the upper surface 61 of the base member 42 to the bottom surface of the groove 63 along the central axis Ca, is desirably about 1 / 10, preferably about 1 / 3, of the thickness of the base member 42. Specifically, for example, if the thickness of the base member 42 is about 20 mm, then the depth is desirably about 2 mm to 7 mm, and if the thickness of the base member 42 is about 50 mm, then the depth is desirably about 5 mm to 17 mm.

[0037] Moreover, the width of the groove 63 in the radial direction (that is, the X-axis direction or the Y-axis direction) is desirably about 5 mm to 35 mm. The groove 63 is an example of a "first heat insulating portion" in the present disclosure.

[0038] 2, the inner region 64 of the base member 42 is provided with an inner refrigerant passage 66 for flowing a refrigerant (e.g., a fluorine-based inert liquid, water, etc.). When viewed in the Z-axis direction, the inner refrigerant passage 66 is arranged in a spiral shape in the inner region 64 of the base member 42, centered on the central axis Ca (i.e., the Z-axis). Furthermore, the inner refrigerant passage 66 is connected to a supply port and a discharge port (not shown) provided on the lower surface 62 of the base member 42, and therefore, the refrigerant supplied to the base member 42 from the supply port flows through the inner refrigerant passage 66 and is discharged from the discharge port to the outside of the base member 42. By flowing the refrigerant through the inner refrigerant passage 66 in this manner, the inner region 64 of the base member 42 can be cooled.

[0039] 2, the outer region 65 of the base member 42 is provided with an outer refrigerant passage 67 for flowing a refrigerant (e.g., a fluorine-based inert liquid, water, etc.). The outer refrigerant passage 67 is arranged in a spiral shape in the outer region 65 of the base member 42 as viewed in the Z-axis direction. That is, the outer refrigerant passage 67 is located outside the inner refrigerant passage 66, sandwiching the annular groove portion 63. The outer refrigerant passage 67 is connected to a supply port and a discharge port (not shown) provided on the lower surface 62 of the base member 42, and the refrigerant supplied to the base member 42 from the supply port flows through the outer refrigerant passage 67 and is discharged from the discharge port to the outside of the base member 42. By flowing the refrigerant through the outer refrigerant passage 67 in this manner, the outer region 65 of the base member 42 can be cooled.

[0040] In this embodiment, the inner refrigerant passage 66 provided in the inner region 64 and the outer refrigerant passage 67 provided in the outer region 65 are provided independently in terms of control system, and the temperature of the refrigerant and the flow rate of the refrigerant can be adjusted separately. The base member 42 has a groove 63 between the inner region 64 and the outer region 65. Therefore, when the refrigerant flows through the outer refrigerant passage 67, the outer region 65 of the base member 42 is cooled independently, and when the refrigerant flows through the inner refrigerant passage 66, the inner region 64 of the base member 42 is cooled independently. At this time, since the base member 42 has the annular groove 63, the inner region 64 can be cooled without being affected by the temperature of the outer region 65, and the outer region 65 can be cooled without being affected by the temperature of the inner region 64. Therefore, a desired clear temperature distribution can be obtained between the inner region 64 and the outer region 65 of the base member 42.

[0041] As shown in Fig. 2, the ceramic member 41 has an insulating space 74 inside. Moreover, the insulating space 74 extends annularly about a central axis Ca (i.e., the Z-axis) as a center as shown in Fig. 3. Therefore, the ceramic member 41 is partitioned by the insulating space 74 into an inner region 75 located inside the insulating space 74 and an outer region 76 located outside the insulating space 74.

[0042] 3, in a state where the base member 42 is joined to the ceramic member 41 via the joining layer 43, the heat insulating space 74 is arranged so as to overlap with the groove portion 63, that is, so as to extend along almost the entire circumference (e.g., 90% or more) in the circumferential direction, as viewed in the Z-axis direction. That is, in this embodiment, the center of the width of the heat insulating space 74 is arranged so as to coincide with the center of the width of the groove portion 63 over almost the entire circumference in the circumferential direction, as viewed in the Z-axis direction.

[0043] In this embodiment, the center of the width direction of the heat insulating space 74 is arranged so as to coincide with the center of the width direction of the groove portion 63 over almost the entire circumference in the circumferential direction when viewed in the Z axis direction, but this is not limited to this. That is, for example, it goes without saying that the center of the width direction of the heat insulating space 74 may be shifted inwardly or outwardly with respect to the center of the width direction of the groove portion 63 when viewed in the Z axis direction.

[0044] Also, the length of the heat insulating space 74 in the direction of the central axis Ca is desirably about 1 / 4 to 1 / 2, and preferably about 1 / 3, of the thickness of the ceramic member 41. Specifically, for example, if the thickness of the ceramic member 41 is about 2 mm, the length is desirably about 0.5 mm to 1 mm, and if the thickness of the ceramic member 41 is about 6 mm, the length is desirably about 1.5 mm to 3 mm.

[0045] As shown in FIG. 2, the bottom of the insulating space 74 is spaced away from the lower surface 52 of the ceramic member 41 toward the adsorption surface 51 by a distance equal to 1 / 3 of the thickness of the ceramic member 41.

[0046] The width of the heat insulating space 74 in the radial direction (i.e., in the X-axis and Y-axis directions) is set wider than the width of the groove portion 63, and is preferably about 15 mm to 35 mm. The heat insulating space 74 is an example of a "second heat insulating portion" in the present disclosure.

[0047] As shown in FIG. 2, the lower surface 52 in the inner region 75 and the outer region 76 of the ceramic member 41 and the upper surface 61 in the inner region 64 and the outer region 65 of the base member 42 are thermally connected by a bonding layer 43 disposed therebetween.

[0048] On the other hand, since no bonding layer 43 is disposed in the annular opening portion of groove portion 63 in the upper surface 61 of base member 42, the lower surface 52 of ceramic member 41 and the upper surface 61 of base member 42 are not thermally connected in the opening portion of groove portion 63 in the upper surface 61 of base member 42.

[0049] 2 and 3, the suction surface 51 of the ceramic member 41 corresponding to the inner region 75 and the outer region 76 when viewed in the Z-axis direction is provided with a large number of columnar protrusions 72. Therefore, when the wafer W is supported by the annular protrusion 71 and the multiple protrusions 72 on the suction surface 51 of the ceramic member 41, i.e., by all the protrusions formed on the suction surface 51, the suction surface 51 in the inner region 75 and the outer region 76 of the ceramic member 41 and the wafer W are thermally connected via the annular protrusion 71 and the multiple protrusions 72.

[0050] On the other hand, the columnar protrusions 72 are not provided on the suction surface 51 of the ceramic member 41, which overlaps with the grooves 63 as viewed in the Z-axis direction, that is, the portion of the suction surface 51 which overlaps with the thermal insulation space 74. Therefore, the wafer W and the ceramic member 41 are not thermally connected to each other.

[0051] In the electrostatic chuck 10 configured as described above, a coolant is supplied from the supply port to the inner coolant passage 66 and the outer coolant passage 67, thereby controlling the temperature of the base member 42. Specifically, it is possible to control the temperature of the inner region 64 of the base member 42 by changing the temperature and flow rate of the coolant supplied from the supply port to the inner coolant passage 66. In addition, it is possible to control the temperature of the outer region 65 of the base member 42 by changing the temperature and flow rate of the coolant supplied from the supply port to the outer coolant passage 67.

[0052] In this embodiment, since the base member 42 has an annular groove 63 between the inner region 64 and the outer region 65, the base member 42 suppresses radial heat transfer between the inner region 64 and the outer region 65 with the groove 63 as a boundary. This further improves the controllability of the temperature distribution control in the inner region 64 and the outer region 65, and therefore makes it possible to obtain a clearer temperature distribution between the upper surface 61 of the inner region 64 and the upper surface 61 of the outer region 65 of the base member 42.

[0053] Moreover, the temperature of the upper surface 61 of the inner region 64 of the base member 42 is thermally transferred to the wafer W via a first heat transfer path extending in the direction of the central axis Ca, specifically, via the bonding layer 43, the inner region 75 of the ceramic member 41, and the numerous columnar protrusions 72. Therefore, the temperature of the inner region of the wafer W, in other words, the temperature of the adsorption surface 51 corresponding to the inner region 75 of the ceramic member 41, can be easily controlled by changing the temperature and flow rate of the coolant supplied from the supply port to the inner coolant passage 66.

[0054] Further, the temperature of the upper surface 61 of the outer region 65 of the base member 42 is transferred to the wafer W via a second heat transfer path extending annularly in the direction of the central axis Ca outside the first heat transfer path, specifically, via the annular bonding layer 43, the annular outer region 76 of the ceramic member 41, and the numerous columnar protrusions 72. Therefore, the temperature of the outer region of the wafer W, in other words, the temperature of the adsorption surface 51 corresponding to the outer region 76 of the ceramic member 41, can be easily controlled by changing the temperature and flow rate of the coolant supplied from the supply port to the outer coolant passage 67.

[0055] In this embodiment, the ceramic member 41 has a heat insulating space 74 at the portion overlapping the groove 63, and the columnar protrusion 72 is not formed at the portion of the suction surface 51 overlapping the groove 63, i.e., overlapping the heat insulating space 74, as viewed in the Z-axis direction. Furthermore, the bonding layer 43 is not disposed at the annular opening of the groove 63 on the upper surface 61 of the base member 42, so that the radial heat transfer between the first heat transfer path and the second heat transfer path is suppressed. Therefore, the temperature formed on the upper surface 61 of the base member 42 is transferred to the wafer W almost as it is, and therefore a clear temperature distribution can be obtained between the inner region and the outer region of the wafer W.

[0056] Furthermore, by changing the temperature and flow rate of the coolant supplied from the supply ports to the inner coolant passage 66 and the outer coolant passage 67, the temperatures of the inner and outer regions of the wafer W can be precisely controlled.

[0057] [Second embodiment] Next, a retaining device according to a second embodiment of the present disclosure will be described in detail with reference to Fig. 4 and Figs. 5(A) to (E). In the description, the same reference numerals will be used to denote components that have the same effects as those in the first embodiment.

[0058] That is, in the first embodiment, the heat insulating space 74 provided in the ceramic member 41 is provided to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41, but in this embodiment, as shown in Fig. 4, the heat insulating space 74 is configured by a gas tunnel (He tunnel) 74. He gas is discharged to the adsorption surface 51 by such a gas tunnel 74, and the He gas is filled between the wafer W and the adsorption surface 51, so that heat transfer between the wafer W and the adsorption surface 51 is possible through the He gas even in places where there are no protrusions 72. Note that Fig. 4 shows a cross-sectional view of the holding device in Fig. 5(B) as an example of a cross-sectional view of the holding device according to the second embodiment.

[0059] In order to make the gas tunnel function also as the heat insulating space 74, it is necessary to devise a shape and arrangement of the gas tunnel, and the details thereof will be described below with reference to Fig. 5. In the following description, the heat insulating space 74 will be described as the gas tunnel 74. In Figs. 5(A) to (E), the groove portion 63 formed in the base member 42 and the gas tunnel 74 formed in the ceramic member 41 are roughly indicated by a single line.

[0060] 5(A), gas tunnel 74 has gas supply port 74A and supply path 74B extending from supply port 74A toward gas tunnel 74. Gas tunnel 74 is arranged so as to be interrupted on the opposite side to the portion connected to supply path 74B. Therefore, gas tunnel 74 is not arranged over the entire circumference of groove portion 63, and there are some portions along the circumference of groove portion 63 where gas tunnel 74 is not arranged.

[0061] In this case, if the circumferential length of the gas tunnel 74 is 5% or more of the entire circumferential length of the groove portion 63, it is possible to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41.

[0062] In Fig. 5(A), the gas tunnel 74 formed in the ceramic member 41 is disposed on the inner periphery side of the groove portion 63 formed in the base member 42, but the center of the width direction of the gas tunnel 74 may be disposed so as to coincide with the center of the width direction of the groove portion 63 over the entire circumference in the circumferential direction as viewed in the Z-axis direction, or may be disposed on the outer periphery side. The same applies to Figs. 5(B) to (E) below.

[0063] As shown in FIG. 5B, the gas tunnel 74 is divided into four parts in the circumferential direction of the groove portion 63. A supply port 74A is connected to a supply path 74B at the center of each of the four divided gas tunnels 74. An exhaust port 74C is formed at both ends of each of the four divided gas tunnels 74. Therefore, at each end of a divided gas tunnel 74, a gap is generated between the end of an adjacent gas tunnel 74. As a result, the four divided gas tunnels 74 do not exist around the entire circumference of the groove portion 63 in the circumferential direction, and no gas tunnel 74 is arranged along the circumferential direction of the groove portion 63 between each end of the gas tunnel 74 and the end of the adjacent gas tunnel 74.

[0064] In this case, if the circumferential length of the gas tunnel 74 is 5% or more of the entire circumferential length of the groove portion 63, it is possible to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41.

[0065] In FIG. 5(B), the gas tunnel 74 formed in the ceramic member 41 is disposed on the inner side of the groove portion 63 formed in the base member 42. However, when viewed in the Z-axis direction, the center of the width of the gas tunnel 74 may be disposed so as to coincide with the center of the width of the groove portion 63 over the entire circumferential direction, or may be disposed on the outer circumferential side.

[0066] 5(C), gas tunnel 74 is disposed in a serpentine manner from the inner periphery side of groove portion 63, straddling groove portion 63, to the outer periphery side of groove portion 63, and then straddling groove portion 63 again to the inner periphery side of groove portion 63. Therefore, in the portion where gas tunnel 74 significantly protrudes to the inner periphery side or the outer periphery side, gas tunnel 74 is not disposed along groove portion 63.

[0067] In this case, since the gas tunnel 74 is disposed around the entire circumference of the groove portion 63, it is possible to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41, but depending on the meandering width of the groove portion 63, the inner region 64 and the outer region 65 of the base member 42 may not coincide with the inner region 75 and the outer region 76 of the ceramic member 41 when viewed in the Z-axis direction. However, depending on the meandering width of the groove portion 63, this can be solved by narrowing the radial width of the gas tunnel 74 (i.e., the X-axis and Y-axis directions) compared to the width of the heat insulating space 74 of the first embodiment, or by widening the radial width of the groove portion 63 (i.e., the X-axis and Y-axis directions) compared to the width of the groove portion 63 of the first embodiment.

[0068] 5(D), the gas tunnel 74 extends around the entire circumference of the groove portion 63 on the inner periphery side of the groove portion 63. A supply path 74B extends from a supply port 74A arranged on the outer periphery side of the groove portion 63 so as to straddle the groove portion 63, and is then connected to the gas tunnel 74.

[0069] Even if the supply port 74A is disposed on the outer periphery of the groove portion 63 in this manner, the gas tunnel 74 is disposed around the entire circumference of the groove portion 63, so that it is possible to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41. Note that, in FIG. 5(D) as well, the gas tunnel 74 formed in the ceramic member 41 is disposed on the inner periphery side with respect to the groove portion 63 formed in the base member 42, but the center of the gas tunnel 74 in the width direction may be disposed so as to coincide with the center of the width direction of the groove portion 63 around the entire circumference in the circumferential direction as viewed in the Z-axis direction, or may be disposed on the outer periphery side.

[0070] 5(E), the gas tunnel 74 extends in the circumferential direction of the groove portion 63 on the inner peripheral side of the groove portion 63, but a part of the gas tunnel 74 extends on the outer peripheral side of the groove portion 63 so as to intersect with the groove portion 63. Therefore, the gas tunnel 74 extending on the outer peripheral side of the groove portion 63 so as to intersect with the groove portion 63 is not disposed along the groove portion 63.

[0071] In this case, if the circumferential length of the gas tunnel 74, excluding the portion extending on the outer circumferential side of the groove portion 63, is 5% or more of the entire circumferential length of the groove portion 63, it is possible to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41.

[0072] In Fig. 5(E), the gas tunnel 74 formed in the ceramic member 41 is disposed on the inner periphery side with respect to the groove portion 63 formed in the base member 42, but the center of the width direction of the gas tunnel 74 may be disposed so as to coincide with the center of the width direction of the groove portion 63 over the entire circumference in the circumferential direction as viewed in the Z-axis direction, or may be disposed on the outer periphery side. In this case, the portion extending on the outer periphery side of the groove portion 63 in Fig. 5(E) may be made to extend on the inner periphery side.

[0073] In this manner, in this embodiment, the shape and arrangement of the gas tunnel 74 are devised so that the gas tunnel 74 also functions as an insulating space. In any of the cases described above, the gas tunnel 74 is capable of suppressing heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41.

[0074] It should be noted that the above-described embodiment is merely an example, does not limit the present disclosure in any way, and various improvements and modifications are possible without departing from the spirit and scope of the present disclosure. For example, in the present embodiment, a chuck electrode is exemplified as the internal electrode that attracts and holds the wafer W on the attracting surface 51, but the internal electrode is not limited to a chuck electrode and may be a high-frequency electrode.

[0075] In this embodiment, the ceramic member 41 is not provided with a heater for heating the ceramic member 41, but a heater may be provided. In this case, it is preferable to dispose separate heaters having different control systems in the inner region 75 and the outer region 76 on the lower surface 62 side of the insulating space 74 within the ceramic member 41.

[0076] In the present embodiment, the first heat insulating portion is configured by an annular groove portion 63 extending from the upper surface 61 of the base member 42 toward the lower surface 62 along the central axis Ca, but is not limited thereto. For example, the first heat insulating portion may be configured by an annular heat insulating space formed inside the base member 42, or by an annular groove portion extending from the lower surface 62 of the base member 42 toward the upper surface 61 along the central axis Ca. In this case, it is preferable that the bottom surface of the heat insulating space is spaced apart from the upper surface 61 by a length equal to 1 / 3 of the thickness of the base member 42. It is also preferable that the annular groove portion extends from the lower surface 62 toward the upper surface 61 by a length equal to 1 / 3 of the thickness of the base member 42 along the central axis Ca.

[0077] In this embodiment, the second heat insulating portion is configured by the heat insulating space 74 formed in the ceramic member 41, but is not limited thereto. For example, the second heat insulating portion may be configured by an annular groove portion extending from the adsorption surface 51 of the ceramic member 41 toward the lower surface 52 along the central axis Ca. In this case, it is preferable that the annular groove portion extends from the adsorption surface 51 toward the lower surface 52 side along the central axis Ca by a length that is ⅓ of the thickness of the base member 42.

[0078] In the present embodiment, the adsorption surface 51 of the ceramic member 41 corresponding to the inner region 75 and the outer region 76 as viewed in the Z-axis direction is provided with a large number of columnar protrusions 72, and the adsorption surface 51 portion overlapping the groove portion 63, i.e., overlapping with the heat insulating space 74, is not provided with the columnar protrusions 72, but this is not limiting. For example, the adsorption surface 51 corresponding to the inner region 75 and the outer region 76 as viewed in the Z-axis direction may be provided with a large number of columnar protrusions 72, and the adsorption surface 51 portion overlapping with the groove portion 63, i.e., overlapping with the heat insulating space 74 may be provided with protrusions 72 such that the number per unit area is less than the number of protrusions 72 provided on the adsorption surface 51 corresponding to the inner region 75 and the outer region 76. [Explanation of symbols]

[0079] 10 Electrostatic Chuck 41 Ceramic materials 42 Base material 51 Adsorption surface 52 Bottom surface 61 Top surface 62 Bottom surface 63 Groove 66 Inner refrigerant passage 67 Outside refrigerant passage 72 Convex 74 Insulated space (gas tunnel) 75 Inner area (ceramic components) 76 Outer area (ceramic components) W wafer

Claims

1. A holding device comprising: a plate-shaped member having a first surface and a second surface provided on an opposite side to the first surface in a first direction; and a base member having a third surface and a fourth surface provided on the opposite side to the third surface, wherein the second surface of the plate-shaped member and the third surface of the base member are thermally connected to each other, the holding device holding an object on the first surface of the plate-shaped member, The base member is a refrigerant flow path for flowing a refrigerant; a first insulating portion having an annular shape extending from the third surface toward the fourth surface when viewed from the first direction, The plate-like member has a second heat insulating portion therein and is arranged so as to overlap the first heat insulating portion when viewed from the first direction, The second insulation section is a gas tunnel having a gas supply port and a supply path extending from the supply port toward the second insulation section, and overlaps with 5% or more of the entire first insulation section when viewed from the first direction; The supply port does not overlap the first insulation section when viewed from the first direction. A holding device characterized in that

2. A holding device comprising: a plate-like member having a first surface and a second surface provided on the opposite side of the first surface in a first direction; and a base member having a third surface and a fourth surface provided on the opposite side of the third surface, wherein the second surface of the plate-like member and the third surface of the base member are thermally connected, and which holds an object on the first surface of the plate-like member, The base member is a refrigerant flow path for flowing a refrigerant; a first insulating portion having an annular shape extending from the third surface toward the fourth surface when viewed from the first direction, The plate-like member has a second heat insulating portion therein and is arranged so as to overlap the first heat insulating portion when viewed from the first direction, The second insulation section is a gas tunnel having a gas supply port and a supply path extending from the supply port toward the second insulation section, and overlaps with 5% or more of the entire first insulation section when viewed from the first direction; A plurality of protrusions are formed on the first surface, The protrusion is disposed so as not to overlap the first heat insulating portion when viewed from the first direction. A holding device characterized in that

3. A holding device comprising: a plate-like member having a first surface and a second surface provided on the opposite side of the first surface in a first direction; and a base member having a third surface and a fourth surface provided on the opposite side of the third surface, wherein the second surface of the plate-like member and the third surface of the base member are thermally connected, and which holds an object on the first surface of the plate-like member, The base member is a refrigerant flow path for flowing a refrigerant; a first insulating portion having an annular shape extending from the third surface toward the fourth surface when viewed from the first direction, The plate-like member has a second heat insulating portion therein and is arranged so as to overlap the first heat insulating portion when viewed from the first direction, The second insulation section is a gas tunnel having a gas supply port and a supply path extending from the supply port toward the second insulation section, and overlaps with 5% or more of the entire first insulation section when viewed from the first direction; The second heat insulating portion is a groove formed on the first surface, or an internal cavity arranged on the first surface side from a position that is 1 / 3 of the thickness of the plate-like member from the second surface in the first direction. A holding device characterized in that

4. In any one of the holding devices according to claims 1 to 3, The first surface of the plate-like member is An inner region located inside the second insulation section when viewed from the first direction, and an outer region located outside the second insulation section when viewed from the first direction, The refrigerant flow path is provided with an inner refrigerant flow path for cooling the inner region and an outer refrigerant flow path for cooling the outer region, which are independent of each other. A holding device characterized in that

5. A holding device comprising: a plate-like member having a first surface and a second surface provided on the opposite side of the first surface in a first direction; and a base member having a third surface and a fourth surface provided on the opposite side of the third surface, wherein the second surface of the plate-like member and the third surface of the base member are thermally connected, and which holds an object on the first surface of the plate-like member, The base member is a refrigerant flow path for flowing a refrigerant; a first insulating portion having an annular shape extending from the third surface toward the fourth surface when viewed from the first direction, The plate-like member has a second heat insulating portion therein and is arranged so as to overlap the first heat insulating portion when viewed from the first direction, The second insulation section is a gas tunnel having a gas supply port and a supply path extending from the supply port toward the second insulation section, and overlaps with 5% or more of the entire first insulation section when viewed from the first direction; A plurality of protrusions are formed on the first surface, the second heat insulating portion is a groove formed on the first surface, or an internal cavity arranged on the first surface side of a position that is 1 / 3 of the thickness of the plate-like member from the second surface in the first direction, When viewed from the first direction, the protrusions are arranged in a greater number in a non-arrangement region of the internal cavity than in an arrangement region of the internal cavity. A holding device characterized in that

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