Electrostatic chuck member and electrostatic chuck device

Abstract

To provide an electrostatic chuck device capable of suppressing abnormal discharge inside a gas hole.SOLUTION: An electrostatic chuck member includes a plate-shaped dielectric substrate having a mounting surface on which a plate-shaped sample is placed and a gas hole penetrating in a thickness direction, an attraction electrode disposed inside the dielectric substrate, a bias electrode disposed inside the dielectric substrate, and a conductive discharge-suppressing member embedded in the dielectric substrate so as to surround the gas hole, and the discharge-suppressing member is disposed electrically independent.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electrostatic chuck member and an electrostatic chuck device. [Background technology]

[0002] Electrostatic chuck devices that support a substrate such as a semiconductor wafer are known. For example, Patent Document 1 describes such an electrostatic chuck device having a structure in which a sample stage that electrostatically attracts an object to be processed has a plurality of gas holes that supply a heat transfer gas between the object to be processed and the sample stage to control the temperature of the object to be processed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-182763 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the electrostatic chuck device as described above, the through hole for gas supply may become the starting point of discharge that leads to damage to the semiconductor wafer. In recent years, plasma etching devices for semiconductor manufacturing have become increasingly powerful for deep hole processing due to the increasing number of semiconductor layers. For this reason, it is necessary to suppress the occurrence of abnormal discharge inside the gas hole.

[0005] An object of the present invention is to provide an electrostatic chuck device capable of suppressing abnormal discharge inside a gas hole. [Means for solving the problem]

[0006] The present invention includes the following inventions [1] to [6]. It is also preferable to combine two or more of the following inventions as necessary. [1] An electrostatic chuck member comprising: a plate-shaped dielectric substrate having a mounting surface on which a plate-shaped sample is placed and a gas hole penetrating in the thickness direction; an attraction electrode disposed inside the dielectric substrate; a bias electrode disposed inside the dielectric substrate; and a conductive discharge-suppressing member embedded in the dielectric substrate so as to surround the gas hole, wherein the discharge-suppressing member is disposed electrically independent. [2] The electrostatic chuck member described in [1], wherein the discharge suppressing member comprises a plurality of pins arranged at intervals in a circumferential direction around a central axis of the gas hole, each of which is continuous in the thickness direction. [3] The electrostatic chuck member according to [1], wherein the discharge suppressing member extends in a circumferential direction around a central axis of the gas hole and is formed into a cylindrical shape that is continuous in the thickness direction. [4] The electrostatic chuck member according to any one of [1] to [3], wherein the discharge suppressing member is provided radially outwardly of the gas hole and spaced apart from an inner circumferential surface of the gas hole. [5] The electrostatic chuck member described in any one of [1] to [4], further comprising a conductive shield layer disposed inside the dielectric substrate on the opposite side of the mounting surface with respect to the chucking electrode and the bias electrode, and extending radially outward from the outer circumferential surface of the discharge suppressing member centered on the discharge suppressing member. [6] An electrostatic chuck device comprising: the electrostatic chuck member according to any one of [1] to [5]; and a base supporting the electrostatic chuck member from an opposite side to the mounting surface, wherein the discharge suppressing member is not in contact with the base. Effect of the Invention

[0007] According to one aspect of the present invention, there is provided an electrostatic chuck device capable of suppressing abnormal discharge inside a gas hole. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of an electrostatic chuck device according to a first embodiment. [Diagram 2]FIG. 2 is a schematic cross-sectional view showing a discharge suppressing member provided in the electrostatic chuck device of the first embodiment. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing a discharge suppressing member provided in the electrostatic chuck device according to the second embodiment. [Figure 4] FIG. 4 is a diagram showing equipotential lines of an electrostatic chuck device of a comparative example that does not have a discharge suppressing member. [Diagram 5] FIG. 5 is a diagram showing equipotential lines of an electrostatic chuck device according to an example of the first embodiment. [Figure 6] FIG. 6 is a diagram showing equipotential lines in another portion of the electrostatic chuck device of the example of the first embodiment. [Figure 7] FIG. 7 is a diagram showing equipotential lines of an electrostatic chuck device according to an example of the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view of an electrostatic chuck device according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the electrostatic chuck device of the present invention will be described with reference to the drawings. In all of the following drawings, the dimensions and ratios of the components may be appropriately changed in order to make the drawings easier to understand.

[0010] [First embodiment] (Electrostatic chuck device as a whole) FIG. 1 is a cross-sectional view of an electrostatic chuck device according to the present embodiment. An electrostatic chuck device 1A shown in FIG. 1 is placed in a vacuum chamber of a plasma processing device with a mounting surface 11a on which a wafer (plate-shaped sample) W is placed facing upward. In each drawing, a Z-axis is shown to explain the reference of the electrostatic chuck device. The Z-axis direction is, for example, a vertical direction. The central axis O of the mounting surface 11a is parallel to the Z-axis. The arrangement of the electrostatic chuck device 1A with respect to the vertical direction is an example, and other arrangements may be used.

[0011] The electrostatic chuck device 1A includes an electrostatic chuck plate (electrostatic chuck member) 10A that attracts and supports a plate-like sample such as a wafer W, and a base 20 that supports the electrostatic chuck plate 10A.

[0012] (Base) The base 20 is made of a thick, disk-shaped metal member. The base 20 supports the electrostatic chuck plate 10A from the lower side (the opposite side to the mounting surface 11a). There is no particular limitation on the material constituting the base 20 as long as it is a metal having excellent thermal conductivity, electrical conductivity, and workability, or a composite material containing such a metal, and for example, aluminum, an aluminum alloy, copper, a copper alloy, stainless steel, etc. are preferably used. The base 20 of this embodiment may be a water-cooled base having a flow path (not shown) therein for circulating a coolant such as water.

[0013] The upper surface 20t of the base 20 is adhered to the lower surface 11b of the dielectric substrate 11 via an adhesive layer 25. The adhesive layer 25 is made of, for example, a heat-resistant resin such as polyimide resin, silicone resin, or epoxy resin, or an insulating sheet-like or film-like adhesive resin.

[0014] (Electrostatic chuck plate) The electrostatic chuck plate 10A includes a dielectric substrate 11, an attraction electrode 30, a bias electrode 40, and a discharge-suppressing member 50A. The attraction electrode 30, the bias electrode 40, and the discharge-suppressing member 50A are embedded in the dielectric substrate 11.

[0015] (Dielectric substrate) The dielectric substrate 11 is a plate-like member that is circular in plan view. In this specification, the thickness direction of the dielectric substrate 11 may be simply referred to as the "thickness direction". In this specification, the electrostatic chuck device will be described with the side in the thickness direction on which the wafer W is mounted being referred to as the "upper side" and the opposite side being referred to as the "lower side". In this specification, the "upper side" and the "lower side" indicate examples of the posture of the electrostatic chuck device when in use, and do not limit the posture of the electrostatic chuck device when in use.

[0016] The dielectric substrate 11 is made of a composite sintered body having mechanical strength and durability against corrosive gas and its plasma. As a dielectric material constituting the dielectric substrate 11, ceramics having mechanical strength and durability against corrosive gas and its plasma are preferably used. As a ceramic constituting the dielectric substrate 11, for example, an aluminum oxide sintered body, an aluminum nitride sintered body, an aluminum oxide-silicon carbide composite sintered body, etc. are preferably used.

[0017] The upper surface of the dielectric substrate 11 is configured with a mounting surface 11a on which the wafer W is placed. That is, the dielectric substrate 11 is provided with the mounting surface 11a on which the wafer W is placed. In this embodiment, a plurality of protrusions 12 are formed at predetermined intervals on the upper surface of the dielectric substrate 11. The tip surfaces of the plurality of protrusions 12 form the mounting surface 11a. The dielectric substrate 11 is formed with recesses 13 between adjacent protrusions 12, which are recessed downward with respect to the mounting surface 11a. The bottom surface 13b of the recesses 13 faces upward (toward the wafer W).

[0018] The dielectric substrate 11 is provided with a gas hole 8. The gas hole 8 penetrates the dielectric substrate 11 in the thickness direction. The gas hole 8 is circular when viewed in the thickness direction. The gas hole 8 is connected to a gas supply device (not shown). The gas hole 8 supplies a cooling gas such as helium (He) to a space between the wafer W placed on the mounting surface 11a and the bottom surface 13b of the recess 13. The supplied cooling gas cools the wafer W placed on the mounting surface 11a. In this embodiment, a case will be described in which only one gas hole 8 is formed in the center of the electrostatic chuck device 1A, but a plurality of gas holes 8 may be provided in the electrostatic chuck device 1A.

[0019] (Adsorption electrode and bias electrode) The attraction electrode 30 and the bias electrode 40 are layered electrodes and conductive members embedded in the dielectric substrate 11. The attraction electrode 30 and the bias electrode 40 are conductive. That is, the attraction electrode 30 and the bias electrode 40 are made of a material with a resistivity of 0.5 Ωm or less. The attraction electrode 30 and the bias electrode 40 are arranged in this order from top to bottom within the dielectric substrate 11.

[0020] The chucking electrode 30 is located inside the dielectric substrate 11. The chucking electrode 30 extends in a layer shape along a plane perpendicular to the thickness direction of the dielectric substrate 11. The chucking electrode 30 is provided with a first hole 30a through which the discharge-suppressing member 50A passes. The first hole 30a is a region in which the hole-shaped chucking electrode 30 is not formed and is formed to surround the discharge-suppressing member 50A when viewed from the thickness direction. The inner diameter of the first hole 30a is sufficiently larger than the outer diameter of the discharge-suppressing member 50A. The inner edge of the first hole 30a is disposed at a distance from the outer peripheral surface of the discharge-suppressing member 50A.

[0021] The chucking electrode 30 is disposed at a predetermined distance below the mounting surface 11a and the bottom surface 13b. The chucking electrode 30 is connected to a DC power source 101 via a first power supply unit 31 extending downward. The chucking electrode 30 generates an electrostatic chucking force by a DC current supplied from the DC power source 101, and chucking the wafer W to the mounting surface 11a. The chucking electrode 30 is not limited to a monopolar chucking electrode, and may be a bipolar chucking electrode consisting of two electrodes having a semicircular shape in a plan view. The chucking electrode 30 may be provided only in a part of the circumferential direction centered on the discharge suppressing member 50A described later, as viewed from the thickness direction. The chucking electrode 30 may be provided in a plurality of locations spaced apart from each other in the circumferential direction centered on the discharge suppressing member 50A, as viewed from the thickness direction.

[0022] The bias electrode 40 is disposed below (opposite the mounting surface 11a) the chucking electrode 30 with a gap therebetween. The bias electrode 40 extends in a layer shape along a plane perpendicular to the thickness direction of the dielectric substrate 11. The bias electrode 40 is connected to an AC power supply 102 via a second power supply part 41 extending downward.

[0023] The bias electrode 40 is provided with a second hole 40a through which the discharge suppressing member 50A passes, and a third hole 40h through which the first power supply part 31 passes. The second hole 40a is a region in which the hole-shaped bias electrode 30 is not formed so as to surround the discharge suppressing member 50A when viewed from the thickness direction. The inner diameter of the second hole 40a is sufficiently larger than the outer diameter of the discharge suppressing member 50A. The inner edge of the second hole 40a is disposed at a distance from the outer peripheral surface of the discharge suppressing member 50A. In this embodiment, the inner diameter of the second hole 40a is approximately equal to the inner diameter of the first hole 30a. Similarly, the third hole 40h is a region in which the hole-shaped bias electrode 30 is not formed so as to surround the first power supply part 31 when viewed from the thickness direction. The inner diameter of the third hole 40h is sufficiently larger than the outer diameter of the first power supply part 31. The inner edge of the third hole portion 40h is disposed with a gap between it and the outer circumferential surface of the first power supply portion 31.

[0024] In this embodiment, the outer periphery 40b of the bias electrode 40 and the outer periphery 30b of the chucking electrode 30 are disposed at approximately the same position when viewed from the thickness direction. As a result, in this embodiment, the bias electrode 40 is disposed so as to cover approximately the entire chucking electrode 30 from below. Note that it is sufficient that at least a portion of the bias electrode 40 overlaps with the chucking electrode 30 when viewed from the thickness direction. That is, at least a portion of the bias electrode 40 overlaps with the chucking electrode 30 when viewed from the thickness direction. Moreover, the bias electrode 40 of this embodiment entirely overlaps with the chucking electrode 30 when viewed from the thickness direction.

[0025] (Discharge suppression member) FIG. 2 is a schematic cross-sectional view showing a discharge suppressing member 50A provided in the electrostatic chuck device 1A of the present embodiment. As shown in FIG. 1 and FIG. 2, the discharge suppressing member 50A is embedded in the dielectric substrate 11 so as to surround the gas hole 8. The discharge suppressing member 50A suppresses discharge in the gas hole 8. The discharge suppressing member 50A of this embodiment includes a plurality of pins 51. The plurality of pins 51 are concentrically arranged at intervals in the circumferential direction centered on the gas hole 8. Each pin 51 extends in the thickness direction of the dielectric substrate 11. The pin 51 is, for example, circular when viewed from the thickness direction. The pin 51 is not limited to being circular when viewed from the thickness direction, and may be polygonal or the like. The number of pins 51 may be, for example, three or more. In this embodiment, for example, six pins 51 are arranged at equal intervals in the circumferential direction.

[0026] These multiple pins 51 are provided radially outwardly of and spaced apart from the inner circumferential surface of gas hole 8. In other words, a dielectric material forming dielectric substrate 11 is interposed between the multiple pins 51 constituting discharge suppressing member 50A and the inner circumferential surface of gas hole 8.

[0027] 1, one end 51s of each pin 51 is disposed a predetermined distance below the mounting surface 11a and the bottom surface 13b. The other end 51t of each pin 51 is disposed a predetermined distance above the lower surface 11b of the dielectric substrate 11. In other words, each pin 51 is not in contact with the metal base 20.

[0028] The discharge suppressing member 50A including the multiple pins 51 is provided electrically independent. In other words, the multiple pins 51 embedded in the dielectric substrate 11 are not electrically connected to other conductors, such as the attraction electrode 30 and the bias electrode 40.

[0029] The chucking electrode 30, the bias electrode 40, and the discharge suppressing member 50A are made of conductive materials. The conductive material used for the discharge suppressing member 50A is preferably at least one selected from the group consisting of molybdenum carbide (Mo2C), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC), carbon black, carbon nanotubes, and carbon nanofibers. The conductive materials used for the chucking electrode 30, the bias electrode 40, and the discharge suppressing member 50A may further include at least one selected from aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), yttrium (III) oxide (Y2O3), yttrium aluminum garnet (YAG), SmAlO3, and the like, in order to control the resistivity.

[0030] The chucking electrode 30, the bias electrode 40, and the discharge-suppressing member 50A may be formed in advance into a predetermined shape, or may be formed by three-dimensional printing, etc. The chucking electrode 30, the bias electrode 40, and the discharge-suppressing member 50A may be embedded in the dielectric substrate 11 successively while being formed by laminating the dielectric substrate 11 in a plurality of steps.

[0031] In the electrostatic chuck plate 10A of the present embodiment, the chucking electrode 30 and the bias electrode 40 are disposed inside the dielectric substrate 11, and therefore a potential difference is generated in each portion inside the dielectric substrate 11 due to the voltage applied to these electrodes 30, 40. The electrostatic chuck plate 10A of the present embodiment includes a conductive discharge-suppressing member 50A provided so as to surround the gas hole 8 of the dielectric substrate 11. With this configuration, since the gas hole 8 is surrounded by the conductive discharge-suppressing member 50A, it is possible to prevent the influence of the electric field of the chucking electrode 30 and the bias electrode 40 from reaching the gas hole 8. As a result, a large potential difference is unlikely to be generated inside the gas hole 8, and discharge of the cooling gas in the gas hole 8 can be suppressed.

[0032] The discharge suppressing member 50A of the present embodiment is embedded in the dielectric substrate 11 so as to surround the gas hole 8, and suppresses discharge in the gas hole 8. With this configuration, the discharge suppressing member 50A can prevent the electric field generated by the chucking electrode 30 and the bias electrode 40 from extending to the radially inner side of the discharge suppressing member 50A. As a result, it is possible to effectively prevent the potential difference from increasing in the gas hole 8 on the radially inner side of the discharge suppressing member 50A. Therefore, it is possible to suppress abnormal discharge inside the gas hole 8.

[0033] In the electrostatic chuck plate 10A of the present embodiment, the discharge suppressing member 50A includes a plurality of pins 51 arranged at intervals in the circumferential direction around the central axis of the gas hole 8. According to this simple configuration, it is possible to suppress abnormal discharge inside the gas hole 8.

[0034] In the electrostatic chuck plate 10A of the present embodiment, the discharge-suppressing member 50A is provided at a distance from the inner circumferential surface of the gas hole 8 to the radially outer side of the gas hole 8. According to this configuration, the dielectric material forming the dielectric substrate 11 is interposed between the inner circumferential surface of the gas hole 8 and the discharge-suppressing member 50A, and it is possible to more effectively prevent the electric field generated by the attraction electrode 30 and the bias electrode 40 from extending to the radially inner side of the discharge-suppressing member 50A.

[0035] [Second embodiment] 3 is a cross-sectional schematic diagram showing a discharge-suppressing member provided in an electrostatic chuck device of the second embodiment. In an electrostatic chuck device 1B of the present embodiment, the configuration of a discharge-suppressing member 50B is different from that of the electrostatic chuck device 1A described above, and the other configurations are common to the electrostatic chuck device 1A. Therefore, the following mainly describes the discharge-suppressing member 50B, and a description of the configurations common to the electrostatic chuck device 1A will be omitted.

[0036] 1, an electrostatic chuck device 1B shown in FIG. 6 includes an electrostatic chuck plate 10B and a base 20. The electrostatic chuck plate 10B includes a dielectric substrate 11, an attraction electrode 30, a bias electrode 40, and a discharge suppressing member 50B.

[0037] The discharge suppressing member 50B is embedded in the dielectric substrate 11 so as to surround the gas hole 8. The discharge suppressing member 50B suppresses discharge in the gas hole 8. When viewed in the thickness direction, the discharge suppressing member 50B of this embodiment is formed into a cylindrical shape that extends in the circumferential direction centered on the gas hole 8 and continues in the thickness direction. The discharge suppressing member 50B of this embodiment has a circular cross-sectional shape when viewed in the thickness direction, and is cylindrical as a whole. The cross-sectional shape of the discharge suppressing member 50B when viewed in the thickness direction is not limited to a circular shape, and may be a polygonal shape, etc.

[0038] The discharge suppressing member 50B is provided radially outwardly of the gas hole 8 and spaced apart from the inner circumferential surface of the gas hole 8. In other words, a dielectric material forming the dielectric substrate 11 is interposed between the discharge suppressing member 50B and the inner circumferential surface of the gas hole 8. One end 50s of the discharge-suppressing member 50B is disposed a predetermined distance below the mounting surface 11a and the bottom surface 13b. The other end 50t of the discharge-suppressing member 50B is disposed a predetermined distance above the lower surface 11b of the dielectric substrate 11. In other words, the discharge-suppressing member 50B is not in contact with the metal base 20.

[0039] The discharge-suppressing member 50B is provided electrically independent. That is, the discharge-suppressing member 50B embedded in the dielectric substrate 11 is not electrically connected to other conductors, such as the attraction electrode 30 and the bias electrode 40.

[0040] The discharge suppressing member 50B of this embodiment is embedded in the dielectric substrate 11 so as to surround the gas hole 8, and suppresses discharge in the gas hole 8. With this configuration, the discharge suppressing member 50B can suppress the electric field generated by the chucking electrode 30 and the bias electrode 40 from extending to the radially inner side of the discharge suppressing member 50B. As a result, it is possible to effectively suppress the potential difference from increasing in the gas hole 8 on the radially inner side of the discharge suppressing member 50B. Therefore, it is possible to suppress abnormal discharge inside the gas hole 8.

[0041] In the electrostatic chuck plate 10B of the present embodiment, the discharge suppressing member 50B is formed in a cylindrical shape that extends in the circumferential direction about the central axis of the gas hole 8 and is continuous in the thickness direction. With this configuration, it is possible to prevent the electric field generated by the attraction electrode 30 and the bias electrode 40 from extending to the radially inner side of the discharge suppressing member 50B over the entire circumferential area of ​​the discharge suppressing member 50A. As a result, it is possible to effectively suppress the discharge of the cooling gas at the gas hole 8.

[0042] (Example) It is generally known that the wafer W mounted on the mounting surface 11a emits secondary electrons from the lower surface side of the wafer W when the etching gas collides with the upper surface. The frequency of occurrence of such a secondary electron emission phenomenon has been increasing with the recent increase in the power of etching. When the secondary electrons emitted to the lower surface side of the wafer W enter the inside of the gas hole 8, the cooling gas may be ionized in the gas hole 8, causing discharge in the gas hole 8. The present inventors have focused on the fact that discharge due to ionization of the cooling gas is likely to occur when the potential difference in the thickness direction in the gas hole 8 between the lower surface of the wafer W and the upper surface of the base 20 is large. The present inventors have attempted to reduce the potential difference in the gas hole 8 and have come up with the configurations according to the embodiments and their modified examples.

[0043] 4 to 7 are diagrams showing simulation results for illustrating the superiority of the electrostatic chuck device 1A of the first embodiment and the electrostatic chuck device 1B of the second embodiment. FIG. 4 shows an electrostatic chuck device 1P of a comparative example that does not have a discharge suppressing member 50A. Meanwhile, FIGS. 5 and 6 show an electrostatic chuck device 1A of an example of the first embodiment, which has a discharge suppressing member 50A compared to the electrostatic chuck device 1A of the comparative example. FIG. 7 shows an electrostatic chuck device 1B of an example of the second embodiment, which has a discharge suppressing member 50B compared to the electrostatic chuck device 1A of the comparative example. FIGS. 4 to 7 are schematic diagrams showing simulation results of equipotential lines of an electric field generated by the chucking electrode 30 and the bias electrode 40.

[0044] In the comparative electrostatic chuck device 1P shown in FIG. 4, equipotential lines are concentrated and arranged vertically around the area on the underside of the wafer W where the gas holes 8 are provided, and it can be seen that the potential difference is large on the underside of the wafer W. On the other hand, in the electrostatic chuck device 1A of the embodiment shown in FIG. 5 and FIG. 6, most of the equipotential lines extending from the end of the bias electrode 40 extend to the upper end of the electrostatic chuck plate 10A on the radial outside of the region where the discharge suppressing member 50A is provided, both in the portion where the pin 51 is provided (see FIG. 5) and in the portion between the pins 51 adjacent in the circumferential direction (see FIG. 6). In the electrostatic chuck device 1B of the embodiment shown in FIG. 7, most of the equipotential lines extending from the end of the bias electrode 40 extend to the upper end of the electrostatic chuck plate 10B on the radial outside of the region where the discharge suppressing member 50B is provided. The number of equipotential lines arranged on the lower side of the wafer W in the electrostatic chuck devices 1A and 1B of the embodiment is smaller than the equipotential lines arranged on the lower side of the wafer W in the electrostatic chuck device 1P of the comparative example. From this, it can be confirmed that the potential difference on the lower side of the wafer W is small in the electrostatic chuck devices 1A and 1B of the embodiment.

[0045] (Modification of the embodiment) 8 is a cross-sectional view of an electrostatic chuck device according to a modified example of the embodiment. The electrostatic chuck device 1C according to this modified example is different from the electrostatic chuck device 1B according to the second embodiment described above only in the configuration of the discharge suppressing member. Note that the same components as those in the second embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

[0046] 8, like the above-described embodiment, an electrostatic chuck device 1C in this modification includes an electrostatic chuck plate 10C and a base 20. The electrostatic chuck plate 10C also includes a dielectric substrate 11, an attraction electrode 30, a bias electrode 40, and a discharge-suppressing member 50C.

[0047] The discharge-suppressing member 50C of this modified example includes a shield layer 55. The shield layer 55 is disposed inside the dielectric substrate 11 below (on the side opposite to the mounting surface 11a) the attraction electrode 30 and the bias electrode 40 with a gap therebetween. The shield layer 55 extends in a layered manner along a plane perpendicular to the thickness direction of the dielectric substrate 11.

[0048] The shield layer 55 contacts the outer peripheral surface of the cylindrical discharge suppressing member 50C and is electrically connected to the discharge suppressing member 50C. The shield layer 55 extends radially outward from the outer peripheral surface of the discharge suppressing member 50C. In this embodiment, the shield layer 55 is formed in a flange shape extending annularly in the circumferential direction. The shield layer 55 may be provided only in a part of the circumferential direction. For example, a plurality of shield layers 55 may be provided at intervals in the circumferential direction. In this case, the plurality of shield layers 55 extend radially from the outer peripheral surface of the discharge suppressing member 50C. In this embodiment, the radially outer outer edge 55s of the shield layer 55 entirely overlaps the bias electrode 40 when viewed in the thickness direction.

[0049] The electrostatic chuck plate 10C of this modification is disposed inside the dielectric substrate 11 on the opposite side (lower side) from the mounting surface 11a side with respect to the attraction electrode 30 and the bias electrode 40, and includes a conductive shield layer 55 extending from the outer circumferential surface of the discharge suppressing member 50C to the outside in the radial direction centered on the discharge suppressing member 50C. This allows an electric field to be formed avoiding the shield layer 55, making it difficult for a potential difference to become large below the discharge suppressing member 50C. As a result, it is possible to prevent a large potential difference from occurring in the gas holes 8 below the discharge suppressing member 50C, and it is possible to suppress discharge of the cooling gas at the gas holes 8.

[0050] Although the embodiments and modifications of the present invention have been described above, the configurations and combinations thereof in the embodiments and modifications are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments. [Explanation of symbols]

[0051] 1A to 1C... electrostatic chuck device, 8... gas hole, 10A to 10C... electrostatic chuck plate (electrostatic chuck member), 11... dielectric substrate, 11a... mounting surface, 20... base, 30... chucking electrode, 40... bias electrode, 50A to 50C... discharge suppressing member, 51... pin, 55... shield layer, O... central axis, W... wafer (plate-shaped sample)

Claims

1. a plate-shaped dielectric substrate having a mounting surface on which a plate-shaped sample is placed and a gas hole penetrating in a thickness direction; an adsorption electrode disposed inside the dielectric substrate; A bias electrode disposed inside the dielectric substrate; a conductive discharge suppressing member embedded in the dielectric substrate so as to surround the gas hole, The discharge suppressing member is provided electrically independent. Electrostatic chuck member.

2. The discharge suppressing member is a plurality of pins arranged at intervals in a circumferential direction around a central axis of the gas hole, each pin being continuous in the thickness direction; The electrostatic chuck member according to claim 1 .

3. The discharge suppressing member is The gas hole is formed in a cylindrical shape extending in a circumferential direction around a central axis thereof and continuing in the thickness direction. The electrostatic chuck member according to claim 1 .

4. The discharge suppressing member is provided radially outwardly of the gas hole and spaced apart from an inner circumferential surface of the gas hole. The electrostatic chuck member according to claim 1 .

5. a conductive shield layer disposed inside the dielectric substrate on a side opposite to the mounting surface side with respect to the chucking electrode and the bias electrode, the conductive shield layer extending from an outer circumferential surface of the discharge suppressing member to an outer side in a radial direction centered on the discharge suppressing member, The electrostatic chuck member according to claim 1 .

6. An electrostatic chuck member according to any one of claims 1 to 5, a base supporting the electrostatic chuck member from an opposite side to the mounting surface, The discharge suppressing member is not in contact with the base. Electrostatic chuck device.

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