Holding device

Abstract

To provide a holding device capable of improving insulation and preventing a decrease in suction force.SOLUTION: In an electrostatic chuck 10 which holds a wafer W on an adsorption surface 51 of a ceramic member 41, the electrostatic chuck 10 includes a ceramic member 41 having an adsorption surface 51 and a lower surface 52 on the opposite side of the adsorption surface 51 in the Z-axis direction, a chuck electrode 53 which is located closest to the adsorption surface 51 among the electrodes provided inside the ceramic member 41, and a via 81 which is connected to the chuck electrode 53 and extends in the Z-axis direction, a plurality of protrusions 72 are formed on the adsorption surface 51, and the via 81 is arranged so as to overlap with the protrusions 72 when viewed in the Z-axis direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] As an example of a holding device, Patent Document 1 discloses a device having a plurality of protrusions formed on the adsorption surface, and an adsorption electrode and An electrostatic chuck having an internal electrode such as a heater electrode is disclosed. In a jack, the terminal pad to which power is supplied from the outside via the power supply terminal is connected to the via and intermediate conductor. This connects the power supply terminals, terminal pads, vias, and internal electrodes to the Electric power is supplied from an external power source to the internal electrodes via the inter-conductor layers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-228361 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above electrostatic chuck, polishing is required to form a plurality of protrusions on the adsorption surface. Since surface treatment such as polishing or blasting is performed, the thickness of the insulating layer between the internal electrode and the adsorption surface varies in parts. The thickness of the insulation film becomes smaller and smaller, and there is a risk of dielectric breakdown occurring in the thinner part. In particular, in the area where the via is connected to the internal electrode, the via pushes up the internal electrode, causing the internal electrode to Since the insulating layer is raised toward the adsorption surface, the thickness of the insulating layer becomes smaller, so that the dielectric breakdown is more likely to occur. It will become easier.

[0005] Here, if the thickness of the insulating layer on the adsorption surface side is increased, the insulation property is improved, and the occurrence of dielectric breakdown is reduced. However, if the thickness of the insulating layer on the adsorption surface is increased, the internal When the electrode is a chuck electrode, the distance between the chuck electrode and the object is long, The adhesive force for holding the object is reduced.

[0006] Therefore, the present disclosure has been made to solve the above-mentioned problems, and provides a method for improving insulation. The object of the present invention is to provide a holding device capable of preventing a decrease in the suction force while preventing the suction force from decreasing. do. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the present disclosure is to The device has a first surface and a second surface provided on the opposite side to the first surface in a first direction. a plate-shaped member and an electrode disposed inside the plate-shaped member, the electrode being located closest to the first surface side; an internal electrode and a conductive member connected to the internal electrode and extending in the first direction; 1. A holding device for holding an object on the first surface of a plate-like member, A plurality of protrusions are formed on the first surface, The conductive member is disposed so as to overlap the protrusion when viewed from the first direction. It is characterized by the fact that

[0008] In this holding device, when viewed from a first direction (when viewed from above), the conductive member overlaps with the protruding portion. Here, "overlapping the convex portion" means that the conductive member is disposed inside the convex portion when viewed from above. In addition to the case where the conductive member is completely included, the case where a part of the conductive member overlaps the protruding portion is also included. As a result, the portion where the conductive member connected to the internal electrode is disposed, where insulation breakdown is most likely to occur, is located on the first surface. Therefore, in order to form the protrusions, The thickness of the insulating layer in the conductive member arrangement portion is reduced by surface processing performed on the first surface for the purpose of reducing the thickness of the insulating layer in the conductive member arrangement portion. Therefore, the insulation property can be improved and the occurrence of dielectric breakdown can be prevented. In addition, the thickness of the insulating layer on the first surface side does not increase, so the internal electrodes can be Even in the case of a chuck electrode, the chucking force of the holding device is not reduced.

[0009] In the above-mentioned holding device, The conductive members are preferably a plurality of vias connected to the internal electrodes.

[0010] The vias may be formed, for example, by forming a through hole in the green sheet and inserting a via into the through hole. The vias are generally filled with metallization ink. When filling the through holes, the thickness of the mask should be increased relative to the thickness of the green sheet. Since the vias are formed to rise, a protrusion occurs in the via arrangement portion (localized on the first surface). Therefore, when the first surface is processed to form a protrusion, There is a risk that the thickness of the insulating layer in the A-positioning portion will decrease.

[0011] By doing so, at least two of the vias connected to the internal electrodes Since a protrusion is formed directly above the vias, the vias connected to the internal electrodes are The thickness of the insulating layer does not decrease, and therefore the insulating properties are improved, preventing the occurrence of dielectric breakdown. In addition, the thickness of the insulating layer does not increase, so the suction of the holding device can be prevented. There is no loss of power.

[0012] In the above-mentioned holding device, The conductive members are preferably all vias connected to the internal electrodes.

[0013] By doing so, convex portions are formed directly above the arrangement portions of all the vias connected to the internal electrodes. Therefore, the thickness of the insulating layer in the via arrangement portion connected to the internal electrode does not decrease. Therefore, the insulation property is further improved, and the occurrence of dielectric breakdown can be reliably prevented. In addition, the thickness of the insulating layer does not increase, so even if the internal electrode is a chuck electrode, it is protected. The suction force of the holding device is not reduced.

[0014] In the above-mentioned holding device, The internal electrode has a protruding portion that protrudes toward the first surface side, It is preferable that the protrusion overlaps the plurality of vias when viewed from the first direction. stomach.

[0015] The thickness of the insulating layer at the protruding part of the internal electrode is thinner than other parts, so the insulation breakdown This is the part where the above phenomenon is most likely to occur. By making the protrusion overlap multiple vias, the protrusion is placed directly above the protrusion. This prevents the thickness of the insulating layer at the protruding portion of the internal electrode from decreasing. Since the insulation property is improved, the occurrence of dielectric breakdown can be prevented. Since the thickness of the insulating layer is not increased, the holding is possible even if the internal electrode is a chuck electrode. The suction power of the device is not reduced.

[0016] In the above-mentioned holding device, It is preferable that all of the vias are arranged so as to overlap one-to-one with the protruding portion. It is.

[0017] By doing this, when multiple vias are arranged so that they overlap with one protrusion, In comparison, the vias are spaced apart, so the heat generated by the vias themselves can cause the first This prevents the occurrence of temperature singularities (areas that are hotter than other areas) on the surface. Therefore, a convex portion is formed directly above the via placement area, so the via placement area connected to the internal electrode The thickness of the insulating layer at the insulating portion does not decrease. Therefore, the insulating property is further improved, and the insulating layer It is possible to reliably prevent edge damage while achieving temperature uniformity on the first surface of the plate-like member. become.

[0018] In the above-mentioned holding device, the plurality of vias; a connection pad connected to the plurality of vias; a plurality of second vias connected to the connection pads and disposed on the second surface side; The plurality of vias and the plurality of second vias do not overlap when viewed from the first direction. It is preferable that the electrodes are arranged so as to be shifted in a second direction perpendicular to the first direction so as to avoid the interference.

[0019] When the via and the second via are arranged in the same position (in a straight line in the first direction), the protrusion of the via arrangement part Since the raised portions overlap, the amount of pushing up toward the first surface side in the via placement area becomes large. If the amount of this pushing up becomes too large, the thickness of the insulating layer will decrease. Therefore, by doing so, the first via arrangement portion is more likely to have a dielectric breakdown. This prevents the amount of push-up toward the surface 1 from becoming too large. Since the thickness of the insulating layer in the It is possible.

[0020] In the above-mentioned holding device, The second vias are arranged so as to overlap the protrusion when viewed from the first direction. It is preferable that the above is done.

[0021] This prevents the thickness of the insulating layer from decreasing even in the area where the second via is located. Since the insulation is improved even in the area where the a is placed, it is possible to reliably prevent the occurrence of insulation breakdown. Cut. Effect of the Invention

[0022] According to the present disclosure, it is possible to improve insulation and prevent a decrease in adsorptive force. A retaining device may be provided. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic perspective view of an electrostatic chuck according to an embodiment; [Diagram 2] 1 is a schematic configuration diagram of an electrostatic chuck of an embodiment of the present invention taken along an XZ cross section. [Diagram 3] 1 is a schematic configuration diagram of an electrostatic chuck in an XY plane according to an embodiment. [Figure 4] 4 is an enlarged cross-sectional view of a via arrangement portion and its vicinity in the ceramic member. FIG. [Diagram 5] FIG. 2 is a cross-sectional view showing a state of a ceramic member before polishing. [Figure 6] FIG. 4 is a cross-sectional view showing the state of a ceramic member after polishing (before blasting). [Figure 7] FIG. 13 is a diagram showing an example in which a via completely overlaps a protrusion as viewed in the Z-axis direction. [Figure 8] FIG. 13 is a diagram showing an example in which a via partially overlaps a protrusion as viewed in the Z-axis direction. [Figure 9] FIG. 13 is a diagram showing an example in which a plurality of vias overlap one protrusion as viewed in the Z-axis direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A holding device according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to an electrostatic chuck for holding a semiconductor wafer. explain.

[0025] <Overall structure of electrostatic chuck> The electrostatic chuck of the present embodiment will be described with reference to FIGS. The device 10 is a device that attracts and holds an object (e.g., a wafer W) by electrostatic attraction. For example, it is used to fix a wafer W in a vacuum chamber of a semiconductor manufacturing device. As shown in FIG. 1, the chuck 10 includes a ceramic member 41, which is a plate-shaped member, and a base member 42 and a bonding layer 43.

[0026] In the following description, for convenience of explanation, the XYZ axes are defined as shown in FIG. Here, the Z axis is the axis along the central axis Ca of the electrostatic chuck 10 (the vertical direction in FIG. 1). The X-axis and Y-axis are radial axes of the electrostatic chuck 10. The direction of the central axis Ca) is an example of the "first direction" in the present disclosure, and the Y-axis direction and the Z-axis direction (i.e. That is, the radial direction of the electrostatic chuck 10) is an example of the "second direction" in the present disclosure.

[0027] The ceramic member 41 is, for example, a disk-shaped member made of ceramics. A wide variety of ceramics are used, but the strength, wear resistance, and durability are the most important. From the viewpoint of plasma properties, for example, aluminum oxide (alumina, Al2O3) or nitride It is preferable to use ceramics containing aluminum nitride (AlN) as the main component. The main component here is the component with the highest content (for example, the volume content is 90 vol % or more).

[0028] The diameter of the ceramic member 41 is, for example, about 150 mm to 300 mm. The thickness of the laminated member 41 is, for example, about 2 mm to 6 mm. The thermal conductivity of the material 41 is 10 to 50 W / mK (more preferably, 18 to 30 W / mK, e.g. It is desirable to keep the brightness within the range of 20 W / mK.

[0029] As shown in FIG. 1 and FIG. 2, the ceramic member 41 has an adsorption surface 51 as an upper surface and a ceramic The chuck member 41 is provided on the opposite side to the chucking surface 51 in the central axis direction (i.e., the Z-axis direction). The ceramic member 41 has a lower surface 52 on which the ceramic member 41 is attached. The adhesive surface 51 is an example of the "first surface" in the present disclosure, and the lower surface 52 is This is an example of the "second aspect" of the present disclosure.

[0030] As shown in FIGS. 2 and 3, the adsorption surface 51 has an annular convex portion 71 formed near its outer edge. A plurality of independent columnar protrusions 72 are formed inside the annular protrusion 71. The annular convex portion 71 is also called a seal band. The cross-sectional shape (XZ cross-section) of the annular convex portion 71 is as follows: 2, the annular protrusion 71 is substantially rectangular. The height of the annular protrusion 71 (the dimension in the Z-axis direction) is, for example, The width of the annular protrusion 71 (the dimension in the X-axis direction) is, for example, , about 0.5mm to 5.0mm.

[0031] As shown in FIG. 3, each of the protrusions 72 has a substantially circular shape when viewed in the Z-axis direction, and is arranged at substantially equal intervals. The cross-sectional shape (XZ cross-section) of each of the protrusions 72 is approximately The height of the protrusion 72 is approximately the same as the height of the annular protrusion 71, and is, for example, 10 μm. The width of the protrusion 72 (the maximum diameter of the protrusion 72 as viewed in the Z-axis direction) is, for example, For example, it is about 0.5 mm to 1.5 mm. The portion on the inside of the annular protrusion 71 where the protrusion 72 is not formed is called a recess 73. It has become.

[0032] The wafer W is then brought into contact with the annular protrusions 71 on the chucking surface 51 of the ceramic member 41 in a plurality of positions. The wafer W is supported by the protrusions 72 and held by the electrostatic chuck 10. When the wafer W is held at 0, the surface (lower surface) of the wafer W and the adsorption surface 5 of the ceramic member 41 are in contact with each other. 1 (more specifically, the recess 73 of the adsorption surface 51). An inert gas (for example, helium gas) is supplied between them.

[0033] As shown in FIG. 2, the ceramic member 41 has a chuck electrode 53 therein. The chuck electrode 53 is, for example, substantially circular when viewed in the Z-axis direction, and is made of a conductive material. The chuck electrode 53 is made of a material such as tungsten or molybdenum. This is an example of the disclosed "internal electrode." The chuck electrode 53 has vias 81a and 81b, A connection pad 82, a via 83a, a terminal pad 84, and a power supply terminal 8 for connecting to a power source (not shown). A voltage is applied from a power source through the wafer W to the adsorption surface 5 by the electrostatic attraction force. The substrate is attracted to and held by the chuck electrode 53. The chuck electrode 53 has vias including vias 81a and 81b. A plurality of vias 83 including a via 83a are connected to the connection pad 82. The diameter of the vias 81 and 83 is, for example, about 0.3 to 0.6 mm. The details of 81 (81a, 81b) and via 83 (83a) will be described later.

[0034] The base member 42 is, for example, a cylindrical member as shown in FIG. 1 (more specifically, a cylindrical member having two circular cylinders with different diameters). The columns are stacked on top of each other with a common central axis (a small straight section on top of a large diameter cylindrical lower section). The upper part of the cylindrical part of the diameter is placed on the stepped cylindrical part. The base member 42 is made of a metal (for example, aluminum or an aluminum alloy). It is preferred that the insulating layer 14 is made of metal, but it may be made of a material other than metal.

[0035] As shown in FIG. 1 and FIG. 2, the base member 42 has an upper surface 61 and a base member 42 ( In the direction of the central axis Ca (see FIG. 3) of the ceramic member 41) (i.e., the Z-axis direction) The upper surface 61 is provided on the opposite side to the lower surface 62. The lower surface 62 is an example of a "third surface" of the present disclosure.

[0036] The diameter of the base member 42 is, for example, about 150 mm to 300 mm at the upper stage and The thickness of the base member 42 (in the Z-axis direction) is, for example, about 180 mm to 350 mm. The dimensions of the base member 42 (aluminum) are, for example, about 20 mm to 50 mm. The thermal conductivity of the material is 180 to 250 W / mK (preferably about 230 W / mK). Preferably within range.

[0037] The base member 42 has a lower surface 52 of the ceramic member 41 and an upper surface 61 of the base member 42. The ceramic member 41 is bonded to the ceramic member 41 by a bonding layer 43 disposed between the ceramic member 41 and the bonding layer 43. In this way, the lower surface 52 of the ceramic member 41 and the upper surface 61 of the base member 42 The bonding layer 43 is made of, for example, a silicone resin or an acrylic resin. The bonding layer 43 is made of an adhesive such as an epoxy resin. The dimension of the bonding layer 43 is, for example, about 0.1 mm to 1.0 mm. The thermal conductivity of the bonding layer 43 is For example, it is 1.0 W / mK. The thermal conductivity of the bonding layer 43 (assumed to be a silicone-based resin) is preferably within the range of 0.1 to 2.0 W / mK (preferably, 0.5 to 1.5 W / mK). stomach.

[0038] As shown in FIG. 2, the base member 42 is made of a refrigerant (for example, a fluorine-based inert liquid or water). The coolant flow path 63 is provided on the lower surface 6 of the base member 42. 2. The supply port and discharge port are connected to the base member 42. The supplied coolant flows through the coolant flow passage 63 and is discharged to the outside of the base member 42 through the discharge port. By flowing the coolant through the coolant flow passage 63 in this manner, the base member 42 is cooled, As a result, the ceramic member 41 is cooled through the bonding layer 43 .

[0039] <About Via> Here, the vias 81 (81a, 81b) and 8 The via 81 (81a, 81b) is As shown in FIG. 4, the chuck electrode 53 is disposed on the lower surface 52 side so as to extend in the Z-axis direction. One end is connected to the chuck electrode 53, and the other end is connected to the connection pad 82. Thus, the chuck electrode 53 and the connection pad 82 are electrically connected through the vias 81 (81a, 81b). The via 83 (83a) is disposed on the lower surface 52 side of the connection pad 82. One end is connected to a connection pad 82 and the other end is connected to a terminal pad 84. As a result, the connection pad 82 and the terminal pad 84 are electrically connected through the via 83 (83a). In this manner, the terminal pad 84 is connected to the via 83 (83a), the connection pad 82, and electrically connected to the chuck electrode 53 through vias 81 (81a, 81b). The via 83 (83a) is an example of a "second via" in the present disclosure.

[0040] The vias 81 (81a, 81b) and the vias 83 (83a) are formed by metallizing the through holes. Therefore, as shown in Figure 4, the ink filling is performed by using a The mask is then placed on the chucking surface 51, and the mask is then placed on the chucking surface 51. In the Z-axis direction, the chuck electrode 53 has the protrusions 53a and 53b. From the outside, the protrusions 53a and 53b overlap with the vias 81a and 81b. In the arrangement portion, a protrusion 82a is formed on the connection pad 82. The protrusion 82a is When viewed in the Z-axis direction, it overlaps with the via 83a.

[0041] Therefore, in the upper surface 51 of the ceramic member 41 before the protrusions 72 are formed, As shown in FIG. 1, the portions directly above the protruding portions 53a, 53b, and 82a are raised. The protrusions 53a and 53b, which are closer to the adsorption surface 51, have a larger protrusion amount than the protrusion 82a. Before the protrusions 72 are formed, the upper surface 51 of the ceramic member 41 is flattened. After this polishing, as shown in FIG. The thickness of the ceramic on the attracting surface 51 side of the chuck electrode 53 is smaller than that of other portions. Since the insulation performance of this part is reduced, there is a risk of dielectric breakdown. do.

[0042] When the convex portion 72 is formed by the blasting process performed after the polishing, the protrusion 5 If the recess 73 is located directly above the chucking electrode 53a, 53b, the chucking surface 51 will be lower than the chucking electrode 53. Since the thickness of the ceramic on the side becomes thinner, dielectric breakdown becomes more likely to occur. If the thickness of the ceramic between the chuck electrode 53 and the recess 73 is increased, the insulation breakdown Although this can prevent the occurrence of damage, the adsorption force of the electrostatic chuck 10 is reduced, It is currently not possible to increase the thickness of the ceramics on the attracting surface 51 side relative to the chuck electrode 53. In addition, in FIG. 4 to FIG. 6, the number of vias 81 connected to the chuck electrode 53 is Vias 81a and 81b, which are a part of the vias 83 connected to the connection pad 82 8 shows a via 83a.

[0043] Therefore, in the electrostatic chuck 10 of the present embodiment, as shown in FIG. The via 83a is arranged so as to overlap the protrusion 72 when viewed in the Z-axis direction. The protrusions 53a and 53b formed on the chuck electrode 53 and the protrusions formed on the connection pad 82 The protruding portion 82a is disposed so as to overlap the protruding portion 72 when viewed in the Z-axis direction.

[0044] The vias 81a and 81b are part of a plurality of vias 81 connected to the chuck electrode 53. These vias 81 (81a, 81b) are the vias provided in the ceramic member 41. The via 83a is located closest to the chucking surface 51. When viewed in the Z-axis direction, the via 83a is located closest to the via 81a. 81b are arranged so as to be shifted in the radial direction (X-axis direction or Y-axis direction) so as not to overlap with 81b. The via 83a is one of a plurality of vias 83 that connect to the connection pad 82.

[0045] Here, "overlapping with the protrusion 72" refers to the vias 81 and 83 as shown in FIG. In addition to the case where the protrusion 72 is completely contained within the protrusion 72 (completely overlaps with the protrusion 72), as shown in FIG. As shown in the figure, a part of the vias 81 and 83 (or the protruding portion) protrudes from the protruding portion 72 ( However, if there is a partial overlap, it means that there is no complete overlap. Since the effect of preventing dielectric breakdown is smaller than when the vias 81a, 81b, 83a ( Alternatively, the protruding portions 53a, 53b, and 82a) completely overlap with the convex portion 72 when viewed in the Z-axis direction. It is desirable to arrange it so that

[0046] As described above, according to the electrostatic chuck 10 of the present embodiment, the vias 81a, 81b and the protrusions The portions 53a and 53b are arranged so as to overlap the protrusion 72 when viewed in the Z-axis direction. The arrangement of the vias 81a and 81b connected to the chuck electrode 53 is such that dielectric breakdown is most likely to occur. The protrusions 72 are arranged so as to overlap the protrusions 72 formed on the adsorption surface 51. Therefore, the surface processing (polishing and blasting) performed to form the protrusions 72 The ceramics on the side of the chucking surface 51 from the chuck electrode 53 in the arrangement portion of the a and b In this embodiment, the thickness of the chuck electrode 5 (insulating layer) does not become thin. The distance from the top surface of 3 to the top surface of the protrusion 72 (the thickness of the ceramic) is about 300 μm. Therefore, the insulating properties of the electrostatic chuck 10 can be improved, and the occurrence of dielectric breakdown can be prevented. In addition, the thickness of the ceramics on the attracting surface 51 side of the chuck electrode 53 can be reduced. Since there is no increase in the weight, the adsorptive force of the electrostatic chuck 10 is not reduced.

[0047] In addition, the via 83 (83a) does not overlap the via 81 (81a, 81b) when viewed in the Z-axis direction. In order to prevent this, the vias 81 are arranged in a radial direction (X-axis direction or Y-axis direction). Prevents the amount of thrust toward the adsorption surface 51 at the arrangement portion of (81a, 81b) from increasing. In other words, the via 81a or 81b and the via 83a can be arranged at the same position (aligned in the Z-axis direction). By arranging the vias in a straight line, the protruding parts of each via arrangement pile up, The amount of thrust toward the suction surface 51 side in the via arrangement portion becomes large, and the protrusion 53a or 53 This prevents the height (dimension in the Z-axis direction) of the vias 81a and 8b from increasing. In the arrangement portion of 1b, the ceramic (insulating layer) on the attracting surface 51 side of the chuck electrode 53 Since the thickness can be prevented from decreasing, the insulating properties of the electrostatic chuck 10 can be improved. Therefore, the occurrence of dielectric breakdown can be prevented.

[0048] The vias 81 and 82 connected to the chuck electrode 53 other than the vias 81a and 81b are The vias 83 connected to the connection pads 82 other than the protrusions 7a and 7b are also connected to the protrusions 7b and 7c as viewed in the Z-axis direction. 2. In this way, all the vias connected to the chuck electrode 53 81 (81a, 81b), and all vias 83 (83a) connected to the connection pad 82 A protrusion 72 is formed directly above the arrangement portion. In this case, the thickness of the ceramic on the attracting surface 51 side of the chuck electrode 53 is prevented from decreasing. Therefore, the insulating properties of the electrostatic chuck 10 are improved, and the prevention of dielectric breakdown is reduced. This makes it possible to more reliably prevent the occurrence of such problems.

[0049] In addition, each of the vias 81 and the vias 83 is arranged so as to overlap one-to-one with the protrusions 72 when viewed in the Z-axis direction. In this way, each of the vias 81 and each of the vias 83 may be arranged at a distance from each other. Therefore, the heat generated by the vias themselves causes a temperature singularity ( This prevents the occurrence of a part that is hotter than the other parts. When the holes 81 or the vias 83 are arranged so as to overlap one protrusion 72 (see FIG. 9), Compared to the conventional method, the temperature of the via arrangement portion is lowered, so that the dielectric breakdown in the via arrangement portion is less likely to occur. It can be made easier.

[0050] It should be noted that the above-described embodiments are merely examples and do not limit the present disclosure in any way. Of course, various improvements and modifications are possible without departing from the spirit and scope of the present invention. For example, in the above embodiment, the chuck electrode 5 is the internal electrode located closest to the chucking surface 51. 3 is shown as an example, the internal electrode is not limited to the chuck electrode 53, and may be a high-frequency electrode. do.

[0051] In the above embodiment, the vias 81 (81a, 81b) and the vias 83 are used as the conductive members. (83a) is shown as an example, but in addition to the via, for example, a metal rod (molded body) is embedded to form an internal connection. Metallic terminals or the like for connecting the terminals may also be used.

[0052] In the above embodiment, the protrusions 72 and the vias 81 or 83 are arranged in a one-to-one relationship when viewed in the Z-axis direction. In other words, only one of the vias 81 or 83 is connected to one protrusion 72. Although they are arranged to overlap, for example, as shown in FIG. 9, a plurality of beams are attached to one protrusion 72. The vias 81 and 83 can be arranged so as to overlap each other. 83) is shown as an example of overlapping vias, but it is acceptable to arrange them so that three or more vias overlap. In this way, when viewed in the Z-axis direction, a plurality of vias can be arranged so as to overlap one protrusion 72. In this case, the size (for example, diameter) of the protrusion 72 in the XY plane is set to be the same as that of the above embodiment. It is preferable to form the electrode larger than in the case of such a one-to-one arrangement. [Explanation of symbols]

[0053] 10 Electrostatic Chuck 41 Ceramic materials 42 Base material 51 Adsorption surface 53 Chuck electrode 72 Convex 81 Via 81a Via 81b Via 82 Connection Pad 83 Beer 83a Via 84 Terminal Pad W wafer

Claims

1. The first surface and the second surface are provided on the opposite side to the first surface in the first direction. a plate-shaped member and an electrode disposed inside the plate-shaped member, the electrode being located closest to the first surface side; The coil includes an internal electrode and a conductive member connected to the internal electrode and extending in the first direction.

1. A holding device for holding an object on the first surface of a plate-like member, A plurality of protrusions are formed on the first surface, The conductive member is disposed so as to overlap the protrusion when viewed from the first direction. There are A holding device characterized in that

2. 2. The holding device according to claim 1, The conductive members are a plurality of vias connected to the internal electrodes. A holding device characterized in that

3. 3. The holding device according to claim 2, The conductive members are all the vias connected to the internal electrodes. A holding device characterized in that

4. The holding device according to claim 2 or 3, The internal electrode includes a protruding portion that protrudes toward the first surface side, The protrusion overlaps with the plurality of vias when viewed from the first direction. A holding device characterized in that

5. 4. The holding device according to claim 3, All of the vias are arranged to overlap one-to-one with the protrusions. A holding device characterized in that

6. In any one of the holding devices according to claims 2 to 4, the plurality of vias; a connection pad connected to the plurality of vias; a plurality of second vias connected to the connection pads and disposed on the second surface side; The plurality of vias and the plurality of second vias do not overlap when viewed from the first direction. The first and second directions are arranged so as to be offset from each other in a second direction perpendicular to the first direction. A holding device characterized in that

7. 7. The holding device according to claim 6, The second vias are arranged so as to overlap the protrusion when viewed from the first direction. It has been A holding device characterized in that

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