Retention device

Abstract

To provide a retention device capable of improving thermal uniformity on a mounting surface.SOLUTION: In an electrostatic chuck 1 which comprises a tabular member 10, a heater electrode 60 and a driver electrode 80 and retains a semiconductor wafer W on a mounting surface 11 of the tabular member 10, the heater electrode 60 includes a first heater electrode 61 and a second heater electrode 62 which is disposed between the first heater electrode 61 and a bottom surface 12 and includes heating resistors more than the first heater electrode 61. The driver electrode 80 includes a first driver electrode 81 which is electrically connected to the first heater electrode 61 and a second driver electrode 82 which is electrically connected to the second heater electrode 62. Relations of the distances between the electrodes in a Z-axis direction of the tabular member 10 satisfies D1<D3 and D1<D2, where a distance between the first heater electrode 61 and the first driver electrode 81 is defined as D1; a distance between the second heater electrode 62 and the second driver electrode 82 is defined as D2; and a distance between the first driver electrode 81 and the second heater electrode 62 is defined as D3.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Electrostatic chucks, for example, are known as holding devices for holding objects. Such electrostatic chucks require uniform temperature (temperature uniformity) on the mounting surface on which the object is placed. If the temperature is not uniform, thermal distortion occurs in the object, making it impossible to perform various processes on the object with high precision.

[0003] Therefore, for example, Patent Document 1 discloses an electrostatic chuck that includes a first heating section (for local heating and having a large number of heating elements) and a second heating section (for overall heating and having a small number of heating elements). In this electrostatic chuck, the second heating section uniformly heats the entire mounting surface, and the first heating section locally adjusts the temperature, thereby achieving a uniform temperature distribution on the mounting surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-115583 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-described electrostatic chuck, the first heat generating portion (for local heating) is disposed closer to the mounting surface than the second heat generating portion (for overall heating). Therefore, due to the presence of power supply paths (vias and pads) to the first heat generating portion, the heat generating elements of the second heat generating portion cannot be disposed over the entire surface. In other words, since the first heat generating portion has a large number of heat generating elements, the number of power supply paths is also large. Therefore, the heat generating elements of the second heat generating portion must be disposed to avoid these numerous power supply paths. Therefore, the heat generating elements of the second heat generating portion cannot be disposed over the entire surface. Therefore, it becomes difficult for the second heat generating portion to uniformly heat the mounting surface.

[0006] In the electrostatic chuck described above, even if the second heat generating portion can uniformly heat the mounting surface, the first heat generating portion may locally heat the mounting surface, which may reduce the uniformity of temperature on the mounting surface. Furthermore, since many power supply paths to the first heat generating portion are arranged near the mounting surface, the heat generated by these power supply paths may further reduce the uniformity of temperature on the mounting surface.

[0007] Therefore, the present disclosure has been made to solve the above-mentioned problems, and has an object to provide a holding device that can improve the temperature uniformity on the mounting surface. [Means for solving the problem]

[0008] In order to solve the above problems, one aspect of the present disclosure is to a plate-like member having a first surface and a second surface that are substantially perpendicular to a first direction; a heater electrode disposed within the plate-like member and including at least one heating resistor; a driver electrode electrically connected to the heating resistor via a conductive member and extending in a surface direction; A holding device for holding an object on the first surface of the plate-like member, The heater electrode is a first heater electrode; A second heater electrode is disposed between the first heater electrode and the second surface of the plate-like member, and includes more heating resistors than the first heater electrode. The driver electrode includes a first driver electrode electrically connected to the first heater electrode, and a second driver electrode electrically connected to the second heater electrode. The relationship of the distances between the electrodes in the first direction of the plate-like member is such that, when the distance between the first heater electrode and the first driver electrode is D1, the distance between the second heater electrode and the second driver electrode is D2, and the distance between the first driver electrode and the second heater electrode is D3, D1 < D3 and D1 < D2 are satisfied.

[0009] In this holding device, since the first heater electrode is disposed closer to the first surface side than the second heater electrode, the conductive member that serves as the power supply path to the second heater electrode does not affect the arrangement of the first heater electrode and the first driver electrode. Therefore, the first heater electrode and the first driver electrode can be arranged over the entire in-plane area. As a result, the first surface can be uniformly heated by the first heater electrode disposed on the first surface side. Therefore, the heat uniformity on the first surface (mounting surface) on which the object is placed can be improved.

[0010] And since the distances D1 to D3 between the electrodes satisfy D1 < D3 and D1 < D2, the distance D1 between the first heater electrode and the first driver electrode is the smallest among the distances between the electrodes. Therefore, the heat of the first heater electrode can be spread in the plane direction by the first driver electrode. As a result, the heat uniformity on the first surface (mounting surface) can be further improved.

[0011] Furthermore, since the distance D2 between the second heater electrode and the second driver electrode and the distance D3 between the first driver electrode and the second heater electrode are greater than the distance D1 between the first heater electrode and the first driver electrode, the heat from the second heater electrode can be prevented from spreading in the surface direction by the first driver electrode and the second driver electrode. This allows the second heater electrode, which has many heating resistors, to accurately control the temperature on the first surface (mounting surface), further improving the thermal uniformity on the first surface (mounting surface).

[0012] In the above-mentioned holding device, The distance D2 between the second heater electrode and the second driver electrode, and the distance D3 between the first driver electrode and the second heater electrode are D2≦D3 It is preferable that the following is satisfied.

[0013] In this way, by making the distance D3 between the first driver electrode and the second heater electrode equal to or greater than the distance D2 between the second heater electrode and the second driver electrode, a sufficient distance between the first driver electrode and the second heater electrode can be ensured. As a result, the first driver electrode can reduce the risk of the heat from the second heater electrode spreading in the planar direction at a position close to the first surface (mounting surface). Therefore, the second heater electrode can more accurately control the temperature (local temperature adjustment) on the first surface (mounting surface), thereby further improving the thermal uniformity on the first surface (mounting surface).

[0014] In any of the above-mentioned holding devices, When the total area of ​​the first driver electrodes and the total area of ​​the second driver electrodes are compared in each plane, the first driver electrodes are preferably larger than the second driver electrodes.

[0015] This also allows the heat from the first heater electrode to be spread in the planar direction by the first driver electrode and transferred to the first surface (mounting surface), while the heat from the second heater electrode is prevented from being spread in the planar direction by the second driver electrode. Therefore, the heat from the first heater electrode can be uniformly transferred to the entire first surface (mounting surface), and the second heater electrode can accurately control the temperature on the first surface (mounting surface) (enhancing the resolution of temperature adjustment). Therefore, the thermal uniformity on the first surface (mounting surface) can be further improved.

[0016] In any of the above-mentioned holding devices, The second driver electrode is preferably disposed between the second heater electrode and the second surface of the plate-like member.

[0017] This makes it possible to prevent the heat from the second heater electrode from spreading in the planar direction on the first surface (mounting surface) side, and therefore the second heater electrode allows for accurate temperature control on the first surface (mounting surface), thereby further improving the thermal uniformity on the first surface (mounting surface). [Effects of the Invention]

[0018] According to the present disclosure, it is possible to provide a holding device that can improve the temperature uniformity on the mounting surface. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic perspective view of an electrostatic chuck according to a first embodiment. [Figure 2] FIG. 2 is a partial cross-sectional view showing the internal configuration of the electrostatic chuck according to the first embodiment. [Figure 3] FIG. 4 is a diagram showing the shape of a first heater electrode. [Figure 4] FIG. 4 is a diagram showing the shape of a first driver electrode. [Figure 5] FIG. 4 is a diagram showing the shape of a second heater electrode. [Figure 6]FIG. 10 is a diagram showing the shape of a second driver electrode. [Figure 7] FIG. 6 is a cross-sectional view showing the internal configuration of an electrostatic chuck according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] 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 holding device used in a semiconductor manufacturing apparatus such as an etching apparatus (such as a plasma etching apparatus) or a film forming apparatus (such as a CVD film forming apparatus or a sputtering film forming apparatus) will be exemplified.

[0021] [First embodiment] First, a first embodiment will be described. An electrostatic chuck 1 of the first embodiment will be described with reference to FIGS. 1 to 6. The electrostatic chuck 1 of this embodiment is a device that attracts and holds a semiconductor wafer W (object) by electrostatic attraction, and is used, for example, to fix the semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing device. As shown in FIG. 1, the electrostatic chuck 1 has a plate-shaped member 10, a base member 20, and a bonding layer 30 that bonds the plate-shaped member 10 and the base member 20 together.

[0022] In the following description, for convenience of explanation, the X, Y, and Z axes are defined as shown in FIG. 1. Here, the Z axis is an axis in the axial direction of the electrostatic chuck 1 (the vertical direction in FIG. 1) and is an example of a "first direction" in the present disclosure. The X and Y axes are axes in the radial direction of the electrostatic chuck 1. Furthermore, the "plane direction" in the present disclosure refers to the direction of the XY plane extending perpendicular to the Z axis direction.

[0023] 1, the plate-like member 10 is a disk-shaped member made of ceramics, and includes a mounting surface 11 as an upper surface on which a semiconductor wafer W is placed, and a lower surface 12 provided on the opposite side of the mounting surface 11 in the thickness direction (Z-axis direction) of the plate-like member 10. The mounting surface 11 is an example of a "first surface" in the present disclosure, and the lower surface 12 is an example of a "second surface" in the present disclosure.

[0024] Although various ceramics are used as the ceramics forming the plate-shaped member 10, it is preferable to use ceramics whose main component is, for example, aluminum oxide (alumina, Al2O3) or aluminum nitride (AlN) from the viewpoints of strength, wear resistance, plasma resistance, etc. Here, the main component means the component with the largest content (for example, a component with a volume content of 90 vol% or more).

[0025] The diameter of the plate-shaped member 10 is, for example, about 150 mm to 350 mm. The thickness of the plate-shaped member 10 is, for example, about 2 mm to 60 mm. The thermal conductivity of the plate-shaped member 10 is preferably in the range of 10 W / mK to 50 W / mK (more preferably, 18 W / mK to 30 W / mK).

[0026] 2, a chuck electrode 50 is disposed inside the plate-like member 10. The chuck electrode 50 has, for example, a substantially circular shape when viewed in the Z-axis direction, and is made of a conductive material (for example, tungsten or molybdenum). The chuck electrode 50 is disposed over almost the entire area of ​​the mounting surface 11 (slightly smaller than the mounting surface 11) when viewed in the Z-axis direction. When a voltage is applied to the chuck electrode 50, an electrostatic attraction force (attraction force) is generated over the entire area of ​​the mounting surface 11, and the semiconductor wafer W is attracted and fixed to the mounting surface 11 by this electrostatic attraction force.

[0027] Also, a heater electrode 60 and a driver electrode 80 electrically connected to the heater electrode 60 are disposed inside the plate-shaped member 10. The heater electrode 60 includes a first heater electrode 61 for uniformly heating the entire mounting surface 11 and a second heater electrode 62 for locally heating the mounting surface 11. In other words, the first heater electrode 61 is a main heater that generates a larger amount of heat than the second heater electrode 62, and the second heater electrode 62 is a sub-heater. This allows the first heater electrode 61 to uniformly heat the entire mounting surface 11 while the second heater electrode 62 locally adjusts the temperature, thereby enabling the temperature distribution on the mounting surface 11 to be uniformly and accurately controlled. The first heater electrode 61 and the second heater electrode 62 are formed of linear heating resistors made of a metal material (e.g., tungsten, molybdenum, etc.) that generate heat when a voltage is applied and a current flows through them.

[0028] The first heater electrode 61 and the second heater electrode 62 are disposed at different positions in the Z-axis direction. In this embodiment, the first heater electrode 61 is disposed above the second heater electrode 62 (on the mounting surface 11 side).

[0029] The driver electrode 80 also includes a first driver electrode 81 electrically connected to the first heater electrode 61, and a second driver electrode 82 electrically connected to the second heater electrode 62. The first driver electrode 81 and the second driver electrode 82 are flat conductor patterns (formed to spread in the XY plane direction) made of a metal material (for example, tungsten or molybdenum) that generates heat when a voltage is applied and a current flows, and are part of the power supply paths of the first heater electrode 61 and the second heater electrode 62.

[0030] The first heater electrode 61 and the first driver electrode 81 will now be described in detail with reference to FIGS. 3 and 4. The first heater electrode 61 includes at least one first heating resistor 100, and is disposed between the mounting surface 11 and the second heater electrode 62 in the Z-axis direction. The total number of first heating resistors 100 provided on the first heater electrode 61 is, for example, approximately 1 to 20. The first heating resistors 100 are patterned to match the shape of each heating zone H1, which is obtained by virtually dividing the plate-like member 10 into a circular or annular (or arc-shaped) shape as viewed in the Z-axis direction. The number of first heating resistors 100 disposed in each heating zone H1 may be two or more.

[0031] 3, the heating zone H1 in this embodiment is set to have two heating zones: a circular heating zone provided inside (at the center) of the plate-like member 10, and an annular heating zone provided around the circular heating zone. The number of first heating resistors 100 is counted as one if the portion is connected only in the surface direction (within the XY plane).

[0032] Pad portions 101 and 102 are formed on both ends of the first heating resistor 100. A via 111 is electrically connected to the pad portion 101, and a via 112 is electrically connected to the pad portion 102 (see FIG. 2). The other end of the via 111 is electrically connected to power supply terminals connected to different external power sources that control the first heating resistor 100, and the other end of the via 112 is electrically connected to the first driver electrode 81. The vias 111 and 112 are rod-shaped conductive members that extend in the Z-axis direction within the plate-like member 10, and are made of a conductive material such as tungsten or molybdenum.

[0033] 4, the first driver electrode 81 electrically connected to the first heating resistor 100 (first heater electrode 61) through the via 112 has, for example, a substantially circular or annular shape when viewed in the Z-axis direction, and is a conductor pattern extending in the radial direction (XY plane direction), and is made of a conductive material (for example, tungsten, molybdenum, platinum, etc.). Note that no conductor pattern is formed in the first driver electrode 81 in the portion where the via 111, the power supply path to the chuck electrode 50, etc. are arranged.

[0034] The first driver electrode 81 is made up of a plurality of conductor patterns, and in this embodiment, two conductor patterns 81a and 81b make up the first driver electrode 81. These two conductor patterns 81a and 81b are arranged with a predetermined gap between them to prevent short circuits.

[0035] 2, a via 113 is electrically connected to the first driver electrode 81. The other end of the via 113 is electrically connected to power supply terminals connected to different external power supplies that individually control the heating zones H1. In other words, the vias 111 and 113 are each connected to a single power supply terminal. This allows power to be supplied to multiple (two in this embodiment) heating zones H1 from different external power supplies. The number of vias 111 and 113 may be the same as the number of heating zones H1, or the number of vias 111 and 113 may be less than the number of heating zones H1 by sharing and consolidating the conductor pattern of the first driver electrode 81.

[0036] In this embodiment, when power is supplied to the first heater electrode 61, power is supplied from a power supply terminal (not shown) to the first heating resistor 100 via the via 111, and is electrically connected from the first heating resistor 100 to another power supply terminal (not shown) via the via 112, the first driver electrode 81, and the via 113.

[0037] Next, the second heater electrode 62 and the second driver electrode 82 will be described in detail with reference to Figures 5 and 6. The second heater electrode 62 is disposed between the first heater electrode 61 and the lower surface 12 of the plate-shaped member 10 (see Figure 2), and is provided with more second heating resistors 200 than the total number of first heating resistors 100. The total number of second heating resistors 200 provided on the second heater electrode 62 is, for example, about 15 to 200.

[0038] As shown in Fig. 5, the second heating resistors 200 are patterned to match the shape of each heating zone H2, which are formed by virtually dividing the plate-like member 10 when viewed in the Z-axis direction, and one second heating resistor 200 is arranged in each heating zone H2. Note that two or more second heating resistors 200 may be arranged in each heating zone H2. For ease of explanation, Figs. 5 and 6 only show some of the second heating resistors 200 and second driver electrodes 82. Note that, like the first heating resistors 100, the number of second heating resistors 200 that are connected only in the planar direction (within the XY plane) is counted as one.

[0039] Pad portions 201 and 202 are formed on both ends of the second heating resistor 200. A via 211 is electrically connected to the pad portion 201, and a via 212 is electrically connected to the pad portion 202 (see FIG. 2). As shown in FIG. 2, the other end of the via 211 is electrically connected to power supply terminals connected to different external power sources that control the second heating resistor 200, and the other end of the via 212 is electrically connected to the second driver electrode 82. The vias 211 and 212 are rod-shaped conductive members that extend in the Z-axis direction within the plate-like member 10, and are made of a conductive material such as tungsten or molybdenum.

[0040] 6, the second driver electrode 82 electrically connected to the second heating resistor 200 (second heater electrode 62) through the via 212 has, for example, a substantially circular or annular shape when viewed in the Z-axis direction, a conductor pattern extending in the radial direction, and is made of a conductive material (for example, tungsten, molybdenum, platinum, etc.). Note that no conductor pattern is formed in the second driver electrode 82 in the portions where the via 211, the first heater electrode 61 (each first heating resistor 100), and the power supply path to the chuck electrode 50 are arranged.

[0041] The second driver electrode 82 is made up of multiple conductor patterns, and in this embodiment, two conductor patterns 82a and 82b make up the second driver electrode 82. These two conductor patterns are arranged with a predetermined gap between them to prevent short circuits.

[0042] 2, a via 213 is electrically connected to the second driver electrode 82. The other end of the via 213 is electrically connected to power supply terminals connected to different external power supplies that individually control the heating zones H2. In other words, the vias 211 and 213 are each connected to a single power supply terminal. This makes it possible to individually supply power to multiple heating zones H2 from different external power supplies. The number of vias 211 and 213 may be the same as the number of heating zones 200, or the number of vias 211 and 213 may be less than the number of heating zones H2 by partially sharing and consolidating the conductor pattern of the second driver electrode 82.

[0043] In this embodiment, when power is supplied to the second heater electrode 62, power is supplied from a power supply terminal (not shown) to the second heating resistor 200 via the via 211, and is electrically connected from the second heating resistor 200 to another power supply terminal (not shown) via the via 212, the second driver electrode 82, and the via 213.

[0044] Here, as can be seen from Figures 4 and 6, when comparing the total area of ​​the first driver electrode 81 and the total area of ​​the second driver electrode 82, the total area of ​​the second driver electrode 82, which has many areas where no conductor pattern is formed to avoid areas where the electrodes are adjacent and many power supply paths, is smaller than the total area of ​​the first driver electrode 81.

[0045] As shown in FIG. 2, the relationship of the distance between the first heater electrode 61 and the first driver electrode 81 and the second heater electrode 62 and the second driver electrode 82 in the Z-axis direction is as follows: D1 <D3、かつ、D1<D2 That is, among the electrodes, the distance D1 between the first heater electrode 61 and the first driver electrode 81 is the smallest.

[0046] Furthermore, the distance D2 between the second heater electrode 62 and the second driver electrode 82 and the distance D3 between the first driver electrode 81 and the second heater electrode 62 are D2≦D3 That is, within the plate-like member 10, the first driver electrode 81 and the second heater electrode 62 are arranged as far apart as possible.

[0047] 1, the base member 20 is disposed on the opposite side of the plate-like member 10 from the mounting surface 11. The base member 20 is formed, for example, in a cylindrical shape. The base member 20 is formed, for example, from a metal (for example, aluminum or an aluminum alloy), but may be formed from a material other than metal.

[0048] 1 and 2, the base member 20 has an upper surface 21 and a lower surface 22 provided on the opposite side to the upper surface 21 in the thickness direction (i.e., the Z-axis direction) of the base member 20. The upper surface 21 of the base member 20 is thermally connected to the lower surface 12 of the plate-like member 10 via a bonding layer 30.

[0049] As shown in FIGS. 1 and 2, the bonding layer 30 is disposed between the lower surface 12 of the plate-like member 10 and the upper surface 21 of the base member 20, and joins the plate-like member 10 and the base member 20 so that heat can be transferred therebetween. This bonding layer 30 is composed of, for example, a resin adhesive such as a silicone-based resin, an acrylic-based resin, or an epoxy-based resin.

[0050] In the electrostatic chuck 1 having such a configuration, the temperature of the semiconductor wafer W adsorbed and held on the mounting surface 11 is controlled by the heater electrode 60 including the first heater electrode 61 and the second heater electrode 62. In the electrostatic chuck 1 of the present embodiment, the first heater electrode 61 is disposed closer to the mounting surface 11 than the second heater electrode 62. Therefore, vias 211 and 213 serving as power supply paths to the second heater electrode 62 do not affect the arrangement of the first heater electrode 61 and the first driver electrode 81. That is, there is no need to avoid the vias 211 and 213, and conductor patterns serving as the first heater electrode 61 and the first driver electrode 81 can also be formed at positions where the vias 211 and 213 are disposed. As a result, the first heater electrode 61 and the first driver electrode 81 can be arranged over substantially the entire area in the plane.

[0051] Therefore, the first heater electrode 61 and the first driver electrode 81 disposed on the mounting surface 11 side can uniformly heat the mounting surface 11. Thus, the heat uniformity on the mounting surface 11 can be improved, and the temperature distribution of the semiconductor wafer W can be uniformly controlled.

[0052] The first heater electrode 61 and the first driver electrode 81, and the second heater electrode 62 and the second driver electrode 82 are arranged such that D1 < D3 and D1 < D2 at the distances D1 to D3 between the electrodes. As a result, the distance D1 between the first heater electrode 61 and the first driver electrode 81 is the smallest among the distances between the electrodes, so that the heat generated by the first heater electrode 61 can be efficiently spread in the plane direction by the first driver electrode 81. Thereby, the heat uniformity on the mounting surface 11 can be further improved.

[0053] Furthermore, the distance D2 between the second heater electrode 62 and the second driver electrode 82 and the distance D3 between the first driver electrode 81 and the second heater electrode 62 are larger than the distance D1 between the first heater electrode 61 and the first driver electrode 81. Therefore, the first driver electrode 81 and the second driver electrode 82 can prevent the heat generated by the second heater electrode 62 from spreading in the surface direction. That is, the second heating resistors 200 provided in the second heater electrode 62 can locally heat the mounting surface 11 with high precision. Furthermore, the second heater electrode 62 is provided with many second heating resistors 200 whose temperatures can be individually controlled, so the second heater electrode 62 can accurately control the temperature of the mounting surface 11. Therefore, the temperature uniformity on the mounting surface 11 can be further improved.

[0054] Furthermore, in the electrostatic chuck 1 of the present embodiment, the distance D3 between the first driver electrode 81 and the second heater electrode 62 is equal to or greater than the distance D2 between the second heater electrode 62 and the second driver electrode 82, so that the distance between the first driver electrode 81 and the second heater electrode 62 can be sufficiently secured (they can be arranged as far apart as possible). As a result, the risk that the heat generated by the second heater electrode 62 will be spread in the planar direction by the first driver electrode 81 at a position close to the mounting surface 11 can be reduced. Therefore, the second heater electrode 62 can more accurately control the temperature of the mounting surface 11 (local temperature adjustment), so that the temperature uniformity on the mounting surface 11 can be further improved.

[0055] Furthermore, in the electrostatic chuck 1 of the present embodiment, the second driver electrode 82 is disposed between the second heater electrode 62 and the lower surface 12, and therefore, it is possible to suppress the heat generated by the second heater electrode 62 from spreading in the planar direction on the mounting surface 11 side. Therefore, the second heater electrode 62 can accurately control the temperature on the mounting surface 11, and the temperature uniformity on the mounting surface 11 can be further improved.

[0056] In the electrostatic chuck 1 of this embodiment, when the areas of the first driver electrode 81 and the second driver electrode 82 are compared as viewed in the Z-axis direction, the first driver electrode 81 is larger than the second driver electrode 82 in terms of total area.

[0057] Therefore, the heat generated by the first heater electrode 61 can be spread in the planar direction by the first driver electrode 81 and transferred to the mounting surface 11, and the heat generated by the second heater electrode 62 can be prevented from spreading in the planar direction by the second driver electrode 82. This allows the heat generated by the first heater electrode 61 to be transferred uniformly to the entire mounting surface 11, and the second heater electrode 62 can accurately control the temperature on the mounting surface 11 (enhancing the resolution of temperature adjustment). Therefore, the temperature uniformity on the mounting surface 11 can be further improved.

[0058] As described above, according to the electrostatic chuck 1 of the present embodiment, the distance D1 between the first heater electrode 61 and the first driver electrode 81 is the shortest among the distances between the electrodes in the Z-axis direction, and therefore the heat generated by the first heater electrode 61 can be spread in the surface direction by the first driver electrode 81. This can improve the temperature uniformity on the mounting surface 11.

[0059] Furthermore, since the distance D2 between the second heater electrode 62 and the second driver electrode 82 and the distance D3 between the first driver electrode 81 and the second heater electrode 62 are larger than the distance D1 between the first heater electrode 61 and the first driver electrode 81, it is possible to prevent the heat generated in the second heater electrode 62 from spreading in the surface direction by the first driver electrode 81 and the second driver electrode 82. As a result, the second heater electrode 62 having a large number of second heating resistors 200 can accurately control the temperature on the mounting surface 11, thereby further improving the thermal uniformity on the mounting surface 11.

[0060] [Second embodiment] Next, a second embodiment will be described. The second embodiment differs from the first embodiment in that a plurality of driver electrodes are provided at different positions in the Z-axis direction. Therefore, the same components as those in the first embodiment will be given the same reference numerals and their description will be omitted as appropriate, and the description will focus on the differences from the first embodiment.

[0061] 7, the electrostatic chuck 1a of this embodiment has a plurality of layers of second driver electrodes 82. In this embodiment, for example, the second driver electrodes 82 are formed in three layers. Of course, when the second driver electrode 82 is formed in multiple layers, the number of layers is not limited to three, and the number may be two, four or more. The second driver electrodes 82 in each layer are electrically connected to each other via vias 214 and 215, and the second driver electrode 82 located on the lower surface 12 side is electrically connected to a via 213.

[0062] When the second driver electrode 82 is formed in multiple layers in this way, the distance D2 from the second heater electrode 62 may be set to the distance from the second driver electrode 82 that is arranged in a position closest to the second heater electrode 62. Furthermore, the area comparison with the first driver electrode 81 may also be performed with respect to the second driver electrode 82 that is arranged in a position closest to the second heater electrode 62. In other words, when the driver electrode is formed in multiple layers, it is sufficient that the driver electrode that is arranged in a position closest to the heater electrode to which it is connected satisfies the various conditions exemplified in the first embodiment.

[0063] The electrostatic chuck 1a in which the second driver electrode 82 is formed of a plurality of layers also satisfies the various conditions exemplified in the first embodiment, and therefore can achieve the same effects as those of the first embodiment.

[0064] It should be noted that the above-described embodiment is merely an example and 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 above-described embodiment, the second driver electrode 82 is disposed between the second heater electrode 62 and the lower surface 12, but the second driver electrode 82 and the second heater electrode 62 may be disposed in the opposite direction in the Z-axis direction (up and down direction).

[0065] In addition, in the above second embodiment, an example was given of a case where the driver electrode is formed of multiple layers, in which the second driver electrode 82 is formed of multiple layers, but the first driver electrode 81 may also be formed of multiple layers. [Explanation of symbols]

[0066] 1. Electrostatic chuck 10 Plate-shaped member 11 Placement surface 12 Bottom side 60 heater electrode 61 First heater electrode 62 Second heater electrode 80 Driver Electrodes 81 First driver electrode 82 Second driver electrode 100 First heating resistor 111 Beer 112 Beer 113 Beer 200 Second heating resistor 211 Beer 212 Beer 213 Beer W: Semiconductor wafer (object)

Claims

1. a plate-like member having a first surface and a second surface that are substantially perpendicular to a first direction; a heater electrode disposed within the plate-like member and including at least one heating resistor; a driver electrode electrically connected to the heating resistor via a conductive member and extending in a surface direction; a holding device for holding an object on the first surface of the plate-like member, The heater electrode is a first heater electrode; a second heater electrode disposed between the first heater electrode and the second surface of the plate-like member, the second heater electrode having a larger number of heating resistors than the first heater electrode; The driver electrode is a first driver electrode electrically connected to the first heater electrode; a second driver electrode electrically connected to the second heater electrode; The relationship of the distances between the electrodes in the first direction of the plate-like member is as follows: When the distance between the first heater electrode and the first driver electrode is D1, the distance between the second heater electrode and the second driver electrode is D2, and the distance between the first driver electrode and the second heater electrode is D3, D1<D3 and D1<D2 A holding device characterized by satisfying the above.

2. 2. The holding device according to claim 1, a distance D2 between the second heater electrode and the second driver electrode, and a distance D3 between the first driver electrode and the second heater electrode, D2≦D3 A holding device characterized by satisfying the above.

3. The holding device according to claim 1 or 2, When the total area of ​​the first driver electrode and the total area of ​​the second driver electrode are compared in each plane, the first driver electrode is larger than the second driver electrode. A holding device characterized by:

4. The holding device according to claim 1 or 2, The second driver electrode is disposed between the second heater electrode and the second surface of the plate-like member. A holding device characterized by:

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