JP7638152B2 - Retaining device - Google Patents

Description

This disclosure relates to a holding device for holding an object.

Conventionally, as a holding device for holding an object such as a wafer during semiconductor manufacturing, an electrostatic chuck is used, which is provided with a plate-shaped member and holds the object by electrostatic attraction on one side of the plate-shaped member. In the electrostatic chuck, it is required to control the temperature of the object to a desired temperature. For example, the following Patent Document 1 discloses an electrostatic chuck in which a heater (heating element) and a gas flow path are formed inside the plate-shaped member, and a base plate equipped with a cooling mechanism is laminated on the other side of the plate-shaped member. In such an electrostatic chuck, the object held on one side is heated by the heater, while being cooled by the cooling mechanism of the base plate. The temperature of the object is controlled to a desired temperature by adjusting the balance between heating and cooling. At this time, a thermally conductive inert gas such as helium gas flows into the gas flow path from a gas inlet hole provided on the other side of the plate-shaped member, flows out from a gas outlet hole provided on one side, and is supplied between the plate-shaped member and the object. This makes it easier for the temperature of the plate-shaped member to be transmitted to the object, improving the temperature controllability of the object.

In holding devices such as electrostatic chucks that hold objects on a plate-like member for processing, it may be necessary to provide multiple heating zones on the plate-like member and heat each heating zone to a different temperature in order to control the processing rate of the objects, etc.

Patent No. 6678458

In view of the above situation, the objective of this technology is to provide a holding device that can easily control multiple heating zones provided on a plate-shaped member that holds an object to different temperatures.

The holding device according to the present disclosure is a holding device that includes a plate-shaped member having a first surface and a second surface perpendicular to a first direction, and a plurality of heating elements arranged in the same position in the first direction on the plate-shaped member, and holds an object on the first surface while heating it, and the plate-shaped member is provided with a plurality of heating zones that are heated to different temperature ranges by the heating elements arranged therein when viewed from the first direction, and a void is formed between the plurality of heating zones when viewed from the first direction, at the same position as the heating elements in the first direction, and extending in a direction perpendicular to the first direction.

The present disclosure provides a holding device that can easily control multiple heating zones on a plate-like member that holds an object to different temperatures.

FIG. 1 is a perspective view showing a schematic configuration of a holding device according to a first embodiment, with a part cut away. FIG. 2 is an XY sectional view showing a schematic outline of the internal structure of the holding device. 3 is a schematic diagram showing an outline of the internal structure of the holding device of FIG. 1 when the holding device is cut along a cross section corresponding to P1-P1 of FIG. FIG. 4 is an XY sectional view showing a schematic outline of the internal structure of the holding device according to the modified example 1-1. FIG. 5 is a schematic diagram showing an outline of the internal structure of the holding device according to Modification 1-1 when the holding device is cut along a cross section corresponding to P2-P2 in FIG. FIG. 6 is an XY sectional view showing a schematic outline of the internal structure of the holding device according to the second embodiment. FIG. 7 is a schematic diagram showing an outline of the internal structure of the holding device according to the second embodiment when the holding device is cut along a cross section corresponding to P3-P3 in FIG. FIG. 8 is an XY sectional view showing a schematic outline of the internal structure of a holding device according to Modification 2-1. FIG. 9 is a schematic diagram showing an outline of the internal structure of the holding device according to Modification 2-1 when the holding device is cut along a cross section corresponding to P4-P4 in FIG. FIG. 10 is an XY sectional view showing a schematic outline of the internal structure of a holding device according to Modification 2-2. FIG. 11 is a schematic diagram showing an outline of the internal structure of the holding device according to Modification 2-2 when the holding device is cut along a cross section corresponding to P5-P5 in FIG. FIG. 12 is a cross-sectional view showing a schematic outline of the internal structure of a holding device according to another embodiment.

[Description of the embodiments of the present disclosure]
First, the embodiments of the present disclosure will be listed and described.
<1> A holding device according to the present disclosure comprises a plate-shaped member having a first surface and a second surface perpendicular to a first direction, and a plurality of heating elements arranged on the plate-shaped member at the same position in the first direction, and holds an object on the first surface while heating it, wherein the plate-shaped member is provided with a plurality of heating zones that are heated to different temperature ranges by the heating elements arranged therein when viewed from the first direction, and the plate-shaped member is provided with voids that are arranged between the plurality of heating zones when viewed from the first direction, and that extend in a direction perpendicular to the first direction, at the same positions as the heating elements in the first direction.

According to the configuration of <1> above, a void is formed between the heating elements that are assigned to each of the multiple heating zones and heat each heating zone to a different temperature range. This makes it difficult for heat to move across heating zones in the plate-shaped member, making it easier to create a temperature difference between the multiple heating zones. As a result, the holding device of the above configuration can easily heat the multiple heating zones to different temperatures. Note that it is sufficient that a portion of the void is at the same position (same height) as the heating element in the first direction. Furthermore, it is preferable that the void extends along the outer periphery of each heating zone when viewed from the first direction, and it is even more preferable that the void extends so as to surround each heating zone.

<2> In the holding device according to the above item <1>, the cavity is a duct provided inside the plate-like member.
Here, the "pipe" refers to a tunnel-shaped void with a closed outer circumferential surface. According to the configuration of <2>, since the void is not a groove-shaped void that opens to the second surface, a structure such as an internal conductive layer including driver wiring connected to the heating element can be embedded in the void on the second surface side as well. As a result, in the holding device of the above configuration, the degree of freedom in designing the internal structure of the plate-shaped member is higher than in a configuration in which the void is a groove that opens to the surface of the plate-shaped member.

<3> In the holding device of <2> above, a gas flow path is formed in the plate-like member, connecting a gas outlet hole provided in the first surface and a gas inlet hole provided in the second surface, the gas flow path includes a plane-parallel flow path portion that is arranged on the first surface side of the heating element in the first direction and extends in a direction perpendicular to the first direction, and the pipe is connected to the gas flow path.
In the configuration of <3>, if an inert gas such as helium gas having a relatively high thermal conductivity is circulated through the ducts in addition to the plane-parallel flow passages of the gas flow passages, the plate-shaped member can be cooled while reducing heat transfer between the heating zones, and the temperature controllability of the first surface can be improved. Here, the gas inlet hole provided on the second surface of the plate-shaped member becomes a temperature singularity having a different temperature from other places, and affects the temperature distribution on the first surface. According to the configuration of <3>, the ducts are connected to the gas flow passages, so that the gas inlet hole of the gas flow passage and the gas inlet hole to the void can be made common. As a result, in the holding device of the above configuration, the temperature controllability of each heating zone can be improved while suppressing an increase in the temperature singularity.

<4> In the holding device according to any one of <1> to <3> above, the cavity extends in the first direction beyond an end of the heating element on the second surface side toward the second surface.
The heat generated from the heating element is transferred to the first surface side, warming the first surface and the object held on that surface. The heat generated from the heating element is also transferred to the second surface side, and is usually cooled (dissipated) by a metal base member or the like arranged on the second surface side. It is presumed that the temperature distribution on the first surface is more susceptible to the heat dissipation state on the second surface side than the heating element. According to the configuration of <4>, by forming a void extending from between the heating elements to the second surface side, the heat transfer between the heating zones in the plate-shaped member is reduced, especially during heat dissipation. As a result, the independence of the temperature control of each heating zone in the holding device can be effectively increased.

[Details of the embodiment of the present disclosure]
Specific examples of the holding device of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is shown by the claims, and is intended to include all modifications within the meaning and scope of the claims. In addition, some of the drawings show the X-axis, Y-axis, and Z-axis of the Cartesian coordinate system XYZ, and each axis direction is drawn to be the same direction in each drawing. In the following description, the Z-axis direction is the up-down direction, and the upper side of FIG. 3 is the up and the lower side of FIG. 3 is the down, but this does not mean that the holding device is necessarily installed in such a posture. In the following description, the up-down direction (Z-axis direction) corresponds to the "first direction" in the claims. In each drawing, for multiple identical members, one member may be given a reference symbol and the reference symbols of other members may be omitted. In addition, the relative size and arrangement of the members in each drawing are not necessarily accurate, and some of the members have been changed in scale for convenience of explanation. In the following description, "parallel" and "orthogonal" do not necessarily have to be in such a strictly positional relationship, and are intended to include "approximately parallel" and "approximately orthogonal" as long as they do not deviate from the gist of the present disclosure.

<Details of First Embodiment>
(Holding device)
The holding device 1 according to this embodiment will be described below with reference to Fig. 1 to Fig. 3. The holding device 1 is an electrostatic chuck that attracts and holds an object (e.g., a wafer W) by electrostatic attraction while heating the object to a predetermined processing temperature (e.g., 50°C to 400°C). The electrostatic chuck is used as a table on which the wafer W is placed, for example, in a process of etching using plasma in a reduced pressure chamber.

1 is a diagram showing a schematic configuration of the holding device 1. The holding device 1 includes a disk-shaped plate-shaped member 10 and a base member 20 that is also disk-shaped. The diameter of the base member 20 is larger than that of the plate-shaped member 10. For example, when the plate-shaped member 10 is disk-shaped with a diameter of 300 mm and a thickness of 3 mm, the base member 20 can be disk-shaped with a diameter of 340 mm and a thickness of 20 mm. Note that both the plate-shaped member 10 and the base member 20 are approximately disk-shaped, and may have irregularities or the like for alignment. The plate-shaped member 10 and the base member 20 are arranged in the vertical direction and bonded together by a bonding material 30. The first surface S1 on the upper side of the plate-shaped member 10 is used as an adsorption surface that adsorbs and holds the wafer W, and the second surface S2 on the lower side of the plate-shaped member 10 is bonded to the base member 20 via the bonding material 30. The lower surface of the base member 20 is used as a third surface S3.

(Plate-shaped member)
The plate-like member 10 will be described as being arranged so that its first surface S1 and second surface S2 are (perpendicular to the first direction) (see FIG. 3, etc.). The plate-like member 10 is an insulating substrate, and can be formed of ceramics containing aluminum nitride (AlN) or alumina (Al ₂ O ₃ ) as the main component, for example. The main component here means the component with the largest content (weight percentage).

As shown in FIG. 1 etc., inside the plate-shaped member 10, a chuck electrode 40 is disposed on the upper side, i.e., the first surface S1 side, and a plurality of heating elements 50 that function as heater electrodes for heating the plate-shaped member 10 are disposed below the chuck electrode 40, i.e., the second surface S2 side. The chuck electrode 40 and the heating elements 50 can be formed from a conductive material containing, for example, tungsten, molybdenum, etc.

The chuck electrode 40 is, for example, planar and parallel to the first surface S1, and is connected to a power source via a terminal or the like. When power is supplied to the chuck electrode 40, electrostatic attraction occurs, and the wafer W is attracted and held on the first surface S1 of the plate-like member 10. The heating element 50 is an electrode that extends along a plane parallel to the first surface S1 (in a direction perpendicular to the first direction), and is arranged to form a linear pattern when viewed from above, as described later with reference to FIG. 2, and is connected to a power source via heater power supply terminals 91, 93 (see FIG. 3, etc.). When power is supplied from the heater power supply terminals 91, 93 to the heating element 50, the plate-like member 10 is heated, and the wafer W held on the first surface S1 of the plate-like member 10 is heated.

The plate-shaped member 10 according to the present embodiment is provided with a plurality of heating zones that are heated to different temperature zones when viewed from above (first direction). FIG. 2 is a schematic diagram showing the state of a cross section of the plate-shaped member 10 when cut at a layer in which the heating element 50 is arranged. The heating zones can be provided to include an inner circumferential zone AZ including the center of the plate surface, an outer circumferential zone CZ including the outer periphery, and an intermediate zone BZ located between the inner circumferential zone AZ and the outer circumferential zone CZ, as shown by different shading in FIG. 2, for example. In this embodiment, the intermediate zone BZ is further divided into two types, and is arranged clockwise from the 12 o'clock position in FIG. 2 as follows: a first intermediate zone B1Z, a second intermediate zone B2Z, a first intermediate zone B1Z, and a second intermediate zone B2Z. Each heating zone AZ, B1Z, B2Z, and CZ may be required to be adjusted to a different temperature zone. For example, the target temperature of the inner circumferential zone AZ is 600±5°C, while the target temperature range of the first intermediate zone B1Z is 620±5°C, the target temperature range of the second intermediate zone B2Z is 630±5°C, and the target temperature range of the outer circumferential zone CZ is 660±5°C. Note that the number, arrangement, and target temperature ranges of the heating zones AZ, B1Z, B2Z, and CZ described here are merely examples, and various changes are possible.

As shown in FIG. 2, heating elements 50A, 50B1, 50B2, and 50C are arranged inside each heating zone AZ, B1Z, B2Z, and CZ to heat the corresponding zone. That is, the multiple heating elements 50 according to this embodiment include an inner heating element 50A arranged inside the inner zone AZ to heat the inner zone AZ, a first intermediate heating element 50B1 arranged inside the first intermediate zone B1Z, a second intermediate heating element 50B2 arranged inside the second intermediate zone B2Z, and an outer heating element 50C arranged inside the outer zone CZ. As shown in FIG. 3, these multiple heating elements 50A, 50B1, 50B2, and 50C are all arranged at approximately the same height.

The heating element 50 is connected to an input terminal 91 and an output terminal 93, which are heater power supply terminals. In this embodiment, as shown in FIG. 2, the input terminal 91 and the output terminal 93 are connected to each of the heating elements 50 arranged in each heating zone via a conductive connection member (individual driver electrode) 55 (see FIG. 3). Specifically, the inner peripheral input terminal 91A and the inner peripheral output terminal 93A are connected to the inner peripheral heating element 50A, and the outer peripheral input terminal 91C and the outer peripheral output terminal 93C are connected to the outer peripheral heating element 50C. In addition, the first input terminal 91B1 and the first output terminal 93B1 are connected to the two first intermediate heating elements 50B1, and the second input terminal 91B2 and the second output terminal 93B2 are connected to the two second intermediate heating elements 50B2. Each heating element 50A, 50B1, 50B2, and 50C can be controlled independently of one another, allowing each heating zone AZ, B1Z, B2Z, and CZ to be heated individually according to the target temperature range.

As shown in FIG. 1, etc., a first surface S1 of the plate-shaped member 10 is provided with a plurality of gas outlet holes 61 (four in FIG. 1, etc.). The outer peripheral edge of the first surface S1 is formed to protrude slightly upward compared to the inner peripheral portion, and when the wafer W is held by suction on the first surface S1, a gap is formed between the wafer W and the first surface S1. On the other hand, a gas inlet hole 62 is provided on the second surface S2 of the plate-shaped member 10 (see FIG. 3, etc.). Then, a gas flow path 60 is formed inside the plate-shaped member 10, which communicates the plurality of gas outlet holes 61 and the gas inlet hole 62. As shown in FIG. 1, the gas flow path 60 includes an upper gas flow path 63 and a lower gas flow path 65, which will be described later, and is formed so that a fluid can move inside the gas flow path 61 over its entire length, and penetrates the inside of the plate-shaped member 10 in the vertical direction. The gas inlet hole 62 of the gas flow path 60 is connected to a base inner flow path 80 formed inside the base member 20, which will be described later (see FIG. 3). When an inert gas such as helium gas, which is a thermally conductive fluid, is introduced into the base internal flow path 80, the gas that flows into the gas flow path 60 from the gas inlet hole 62 of the second surface S2 flows through the gas flow path 60 and flows out from the gas outlet hole 61 of the first surface S1, filling the gap between the plate-like member 10 and the wafer W. This makes it easier for the temperature of the first surface S1 to be transmitted to the wafer W, improving the temperature controllability of the wafer W.

(Joint material)
As shown in FIG. 1 and other figures, the bonding material 30 is located between the plate-like member 10 and the base member 20 and bonds them together. For example, a silicone-based organic bonding agent, an inorganic bonding agent, or a bonding sheet containing an Al-based metal adhesive can be used as the bonding material 30. The bonding material 30 preferably has high adhesive strength to both the plate-like member 10 and the base member 20, as well as high heat resistance and thermal conductivity. Although not shown in the figure, a hole is provided in the bonding material 30 at a position opposite the gas inlet hole 62 formed in the plate-like member 10, and a flow path in the bonding material that penetrates the bonding material 30 in the vertical direction is formed.

(Base member)
1 and other drawings, the base member 20 is joined to the lower side of the plate-like member 10, i.e., the second surface S2 side, by a joining material 30. The lower surface of the base member 20 (the surface opposite to the plate-like member) is defined as the third surface S3. The base member 20 can be composed mainly of, for example, aluminum, an aluminum alloy, a composite of metal and ceramics (Al-SiC), or ceramics (SiC). As described above, the base member 20 is in the shape of a disk with a larger diameter than the plate-like member 10, and the entire plate-like member 10 is placed on the base member 20.

As shown in FIG. 1 etc., a coolant passage 21 is formed inside the base member 20. Plasma heat is cooled by flowing a coolant such as water or a fluorine-based inert liquid through the coolant passage 21. When the coolant flows through the coolant passage 21, the base member 20 is cooled, the plate-like member 10 is cooled by thermal conduction through the bonding material 30, and the wafer W held on the first surface S1 of the plate-like member 10 is further cooled. The temperature of the wafer W is controlled by adjusting the flow of the coolant.

As shown in FIG. 3, a bottom surface opening 81 is provided on the third surface S3 of the base member 20. Inside the base member 20, an internal base flow path 80 is formed that extends in the vertical direction (perpendicular to the first surface S1) and connects the bottom surface opening 81 to an internal bonding material flow path provided at a position opposite the gas inlet hole 62 (penetrating the inside of the base member 20 in the vertical direction).

As shown in FIG. 3, heater power supply terminals 91, 93 are inserted into the base member 20 so as to penetrate it in the vertical direction. The heater power supply terminals 91, 93 can be made of a metal such as nickel (Ni). The lower end of each heater power supply terminal 91, 93 is exposed on the lower surface of the base member 20 and is connected to a power source (not shown). The upper end of each heater power supply terminal 91, 93 is exposed on the upper surface of the bonding material 30 and is connected to the heating element 50 via a connecting member 55 or the like. The heating element 50 generates heat when power is supplied from the power source connected to the heater power supply terminals 91, 93. As described above, in this embodiment, input terminals 91A, 91B1, 91B2, and 91C and output terminals 93A, 93B1, 93B2, and 93C are connected to the heating elements 50A, 50B1, 50B2, and 50C, respectively, and each of the heating elements 50A, 50B1, 50B2, and 50C can be controlled independently of one another.

(Gas flow path)
The gas flow passage 60 formed inside the plate-like member 10 will be described again. As described with reference to FIG. 1, the gas flow passage 60 according to this embodiment includes an upper gas flow passage 63 formed at a position closer to the first surface S1 in the vertical direction (first direction) and a lower gas flow passage 65 formed closer to the second surface S2 than the upper gas flow passage 63. The gas flow passage 60 according to this embodiment is formed to have a tunnel-shaped pipe having a substantially rectangular cross section over its entire length. The cross-sectional shape of the pipe is not particularly limited, and can be formed to have a cross-sectional shape such as a substantially rectangular, substantially circular, or substantially semicircular shape. The gas flow passage 60 according to this embodiment is formed to have a substantially rectangular cross-sectional shape over its entire length.

3, the upper layer gas flow passage 63 includes an upper layer parallel portion 63T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), and an upper layer connection portion 63V connecting the gas outflow hole 61 and the upper layer parallel portion 63T. The upper layer parallel portion 63T is formed inside the plate-shaped member 10, below the chuck electrode 40 and above the heating element 50. As shown in FIG. 2, the upper layer parallel portion 63T according to this embodiment extends in an annular shape around the radial center of the intermediate zone BZ when viewed from above (from the first direction), and a total of four gas outflow holes 61 are formed, one each in the first intermediate zone B1Z and the second intermediate zone B2Z provided in the intermediate zone BZ.

3, the lower gas flow path 65 includes a lower surface parallel portion 65T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), a first connection portion 65V1 connecting the upper surface parallel portion 63T and the lower surface parallel portion 65T, and a second connection portion 65V2 connecting the lower surface parallel portion 65T and the gas inlet hole 62. In this embodiment, the lower surface parallel portion 65T corresponds to the "void" in the claims. The lower surface parallel portion 65T according to this embodiment is a part of the gas flow path 60 and is connected to the gas flow path 60. The lower surface parallel portion 65T is arranged at approximately the same height as the multiple heating elements 50 inside the plate-shaped member 10. More specifically, in this embodiment, the top surface of the lower surface parallel portion 65T is located at approximately the same height as the upper end of the heating element 50, and the bottom surface is located below the lower end of the heating element 50, and a part of the lower surface parallel portion 65T is located at the same height as the heating element 50.

2, the lower surface parallel portion 65T is disposed between each heating zone provided on the plate-shaped member 10 when viewed from above (viewed from the first direction). Specifically, the lower surface parallel portion 65T extends in the circumferential direction along the boundaries between the inner peripheral zone AZ and the intermediate zone BZ and between the intermediate zone BZ and the outer peripheral zone CZ, and also extends in the radial direction along the boundaries between the first intermediate zone B1Z and the second intermediate zone B2Z provided in the intermediate zone BZ. In this embodiment, the first connection portion 65V1 is located at the boundary between the second intermediate zone B2Z and the outer peripheral zone CZ on the upper left side in FIG. 2, and the second connection portion 65V2 is located at the boundary between the first intermediate zone B1Z and the outer peripheral zone CZ on the upper right side in FIG. 2.

The method of forming the gas flow passage 60 including the lower layer parallel surface portion 65T is not particularly limited, and various known methods can be used. For example, when manufacturing the plate-shaped member 10 using multiple green sheets containing aluminum nitride powder or the like, multiple green sheets to which a metallization paste is applied in a specific pattern are stacked to create multiple block bodies, grooves are formed on one or both surfaces of one or more block bodies, and other block bodies are attached to the surfaces with the grooves. Then, by carrying out processes such as compression bonding, firing, and grinding and drilling, a gas flow passage 60 having parallel surface portions of any height and shape can be formed inside the plate-shaped member 10.

(Use of Retention Device)
The holding device 1 is used, for example, as a part of a semiconductor manufacturing apparatus. When a wafer W is placed on a first surface S1 of the holding device 1 installed in a chamber of the semiconductor manufacturing apparatus and power is supplied from a power source to a chuck electrode 40, an electrostatic attraction is generated and the wafer W is attracted to the first surface S1. When a source gas is introduced into the chamber and a voltage is applied, plasma is generated and the wafer W is processed.

When the wafer W is processed, when power is supplied from the power source to the heating element 50 via the heater power supply terminals 91 and 93, the plate-shaped member 10 and the wafer W are heated. On the other hand, when a coolant is flowed through the coolant passage 21, the wafer W is cooled. At this time, a thermally conductive gas is introduced from the lower surface opening 81 of the base member 20, and the gas that flows through the base internal passage 80 and the gas passage 60 flows out from the gas outlet hole 61 of the first surface S1 of the plate-shaped member 10 and fills the gap formed between the first surface S1 and the wafer W, thereby controlling the temperature of the wafer W with high precision. In the holding device 1 according to this embodiment, the heating elements 50A, 50B1, 50B2, and 50C are individually controlled, so that the heating zones AZ, B1Z, B2Z, and CZ of the plate-shaped member 10 can be adjusted to different target temperature zones. As a result, the wafer W held on the first surface S1 can be heated to different target temperature zones for each area facing each heating zone AZ, B1Z, B2Z, and CZ of the plate-shaped member 10, and the desired processing rate, etc. can be obtained for each area.

(Effects of this embodiment)
As described above, the holding device 1 according to this embodiment comprises a plate-shaped member 10 having a first surface S1 and a second surface S2 perpendicular to a first direction (vertical direction, Z-axis direction), and a plurality of heating elements 50 arranged at the same position in the first direction on the plate-shaped member 10, and holds a wafer (object) W on the first surface S1 while heating it. The plate-shaped member 10 is provided with a plurality of heating zones AZ, B1Z, B2Z, CZ which are heated to different temperature zones by heating elements 50A, 50B1, 50B2, 50C arranged therein, respectively, as viewed from the first direction, and the plate-shaped member 10 is provided with a lower surface parallel portion (void) 65T which is arranged between the plurality of heating zones AZ, B1Z, B2Z, CZ as viewed from the first direction, and extends in a direction perpendicular to the first direction, at the same position as the heating elements 50A, 50B1, 50B2, 50C in the first direction.

Even if the heating elements 50A, 50B1, 50B2, and 50C are assigned to each of the multiple heating zones AZ, B1Z, B2Z, and CZ and can be controlled individually, in reality, the heating zones AZ, B1Z, B2Z, and CZ provided on the plate-shaped member 10 are connected to each other, so heat transfer may occur beyond the boundaries of each heating zone AZ, B1Z, B2Z, and CZ. For example, the heat generated from the first intermediate heating element 50B1 also moves in a direction perpendicular to the first direction along a plane parallel to the first surface S1, and is transmitted from the first intermediate zone B1Z to the radially adjacent inner zone AZ and outer zone CZ, and to the circumferentially adjacent second intermediate zone B2Z. For this reason, it is difficult to create a temperature difference between adjacent heating zones AZ, B2Z, and CZ, and it may be difficult to adjust each heating zone AZ, B1Z, B2Z, and CZ to a target temperature range that is different from each other.

In the holding device 1 according to the present embodiment, when viewed from above (first direction), a lower surface parallel portion (void) 65T is formed between the heating elements 50A, 50B1, 50B2, 50C that are assigned to each of the multiple heating zones AZ, B1Z, B2Z, CZ and heat each heating zone to a different target temperature range. Due to the presence of this lower surface parallel portion (void) 65T, heat transfer across the heating zones in the plate-like member 10 is less likely to occur, making it easier to form a temperature difference between the multiple heating zones. As a result, in the holding device 1 according to the present embodiment, the multiple heating zones AZ, B1Z, B2Z, CZ can be easily heated to different target temperature ranges. When viewed from above (first direction), the lower surface parallel portion (void) 65T of the present embodiment extends along the outer contour of each heating zone AZ, B1Z, B2Z, CZ. In particular, the inner circumferential zone AZ extends to surround the entire zone, which is preferable in that it effectively reduces heat transfer between heating zones without loss of heat.

In addition, in the holding device 1 according to this embodiment, the lower surface parallel portion (void) 65T is a duct provided inside the plate-like member 10. In other words, the lower surface parallel portion 65T is a tunnel-shaped void with a closed outer peripheral surface, and is not a groove-shaped void that opens to the second surface S2. Therefore, an internal conductive layer such as a connection member 55 that connects to the heating element 50 can be embedded on the second surface S2 side of the lower surface parallel portion 65T. As a result, the holding device 1 according to this embodiment has a higher degree of freedom in designing the internal structure of the plate-like member 10 compared to a configuration in which the void is a groove provided on the surface of the plate-like member (see FIG. 12).

In addition, in the holding device 1 of this embodiment, the plate-like member 10 is formed with a gas flow path 60 that connects a gas outlet hole 61 provided on the first surface S1 and a gas inlet hole 62 provided on the second surface S2, and the gas flow path 60 includes an upper layer plane-parallel portion (plane-parallel flow path portion) 63T that is disposed on the first surface S1 side of the heating element 50 in the first direction and extends in a direction perpendicular to the first direction, and a lower layer plane-parallel portion (pipe) 65T is connected to the gas flow path 60.

In the holding device 1, if an inert gas such as helium gas having a relatively high thermal conductivity is circulated through the lower parallel portion (pipe) 65T in addition to the upper parallel portion 63T of the gas flow path 60, the temperature controllability of the first surface S1 can be improved compared to when the inert gas is not circulated through the lower parallel portion 65T. In order to heat the heating zones located on both sides of the lower parallel portion 65T when viewed from above to different target temperature zones, it is preferable that heat transfer through the lower parallel portion 65T is unlikely to occur. For this reason, the inert gas that communicates the gas flow path 60 is one having a lower thermal conductivity than the material forming the plate-shaped member 10. When an inert gas having a higher thermal conductivity than air is circulated through the lower parallel portion 65T, there is a possibility that heat transfer across the heating zones will occur more easily than when the lower parallel portion 65T is filled with air, but compared to a conventional configuration in which the lower parallel portion 65T is not formed, heat transfer across the heating zones is reduced. In addition, the gas inlet hole 62 provided on the second surface S2 of the plate-like member 10, and in turn the lower surface opening 81 of the base member 20 connected thereto, become temperature singular points with temperatures different from other points and affect the temperature distribution of the first surface S1. However, in the holding device 1 according to this embodiment, the lower surface parallel portion (pipe) 65T is connected to the gas flow path 60, so that the gas inlet hole 62 of the gas flow path 60 and the gas inlet hole 62 to the lower surface parallel portion (pipe) 65T can be made common. As a result, in the holding device 1 according to this embodiment, the temperature controllability of each heating zone can be improved while suppressing an increase in temperature singular points.

In addition, in the holding device 1 according to this embodiment, the lower surface parallel portion (void) 65T extends in the first direction beyond the end (lower end) of the heating element 50 on the second surface side to the second surface S2 side. In other words, the lower surface parallel portion 65T according to this embodiment has a top surface that is approximately the same height as the upper end of the heating element 50, and a bottom surface that is located below the lower end of the heating element 50, with a portion located at the same height as the heating element 50 (same position in the first direction) and the remaining portion located below the heating element 50 (towards the second surface S2 in the first direction).

The heat generated by the heating element 50 is transferred to the first surface S1 side, warming the first surface S1 and the wafer (object) W held on that surface. The heat generated by the heating element 50 is also transferred to the second surface S2 side, and is cooled (dissipated) by the base member 20 joined to the second surface S2. It is believed that the temperature distribution of the first surface S1 is more susceptible to the heat dissipation state on the second surface S2 side than the heating element 50. In the holding device 1, the lower layer parallel portion (void) 65T extending from between the heating elements 50 to the second surface S2 side is formed, thereby reducing the heat transfer between heating zones inside the plate-like member 10, especially during heat dissipation. As a result, the holding device 1 can effectively increase the independence of the temperature control of each heating zone.

<Modification 1-1 of First Embodiment>
A holding device 101 according to Modification 1-1 of the first embodiment will be described below with reference to Figures 4 and 5. The holding device 101 according to this embodiment differs from the holding device 1 according to the first embodiment mainly in the structures of the upper layer gas flow passage 163 and the lower layer gas flow passage 165 formed inside the plate-like member 110. In the following description, the description of the same configuration as in the first embodiment will be omitted (the same applies to the second and subsequent embodiments).

As shown in FIG. 4, the plate-like member 110 of the holding device 101 is provided with a gas inlet hole 162 between one of the intermediate zones BZ (the first intermediate zone B1Z in the upper right corner in FIG. 4) and the outer circumferential zone CZ. Also, as shown in FIG. 5, the base member 120 of the holding device 101 is provided with a base inner flow passage 180 that connects the lower surface opening 181 of the third surface S3 with the gas inlet hole 162. In the plate-like member 110 according to this embodiment, the lower surface parallel portion 165T, which is a portion extending in the circumferential direction between the outer circumferential zone CZ and the intermediate zone BZ shown in FIG. 4, and the portion extending in the circumferential direction between the intermediate zone BZ and the inner circumferential zone AZ, are formed so as to be connected in one direction. Specifically, the upper layer gas flow passage 163 and the lower layer gas flow passage 165 according to this embodiment are structured so that gas flows as follows. When the thermally conductive gas is introduced from the lower surface opening 181 of the third surface S3, the gas that flows into the lower gas flow passage 165 from the gas inlet hole 162 of the second surface S2 passes through the second connection portion 165V2 and reaches the lower surface parallel portion 165T. The gas that reaches the lower surface parallel portion 165T circulates counterclockwise between the outer peripheral zone CZ and the intermediate zones B1Z and B2Z, changes direction between the second intermediate zone B2Z at the lower right and the first intermediate zone B1Z at the upper right in FIG. 4, and flows toward the radial center. When it reaches the vicinity of the inner peripheral zone AZ, it changes direction again and circulates clockwise between the intermediate zone BZ and the inner peripheral zone AZ. At this time, the gas also flows radially outward between the first intermediate zone B1Z and the second intermediate zone B2Z. The gas that reaches the first connection part 165V1 provided in the first middle zone B1Z at the top right flows upward and flows into the upper surface parallel part 163T of the upper gas flow passage 163, passes through the upper connection parts 163V provided in each middle zone BZ, and flows out through the four gas outflow holes 161 to the first surface S1 side.

By forming the upper gas flow passage 163 and the lower gas flow passage 165 as in this modified example, gas can flow more smoothly while reducing heat transfer between each heating zone.

<Details of the Second Embodiment>
A holding device 201 according to the second embodiment will be described with reference to Fig. 6 and Fig. 7. The holding device 201 according to the present embodiment differs from the holding device 1 according to the first embodiment mainly in the structures of the upper gas flow passage 263 and the lower gas flow passage 265, and the connection structure of the intermediate heating elements 250B1, 250B2 and the heater power supply terminals 291, 293.

The holding device 201 is significantly different from the holding device 1 in that the lower layer gas flow passage 265 formed inside the plate-like member 210 is not connected to the upper layer gas flow passage 263. That is, in this embodiment, the lower layer parallel surface portion 265T arranged between the heating elements 250A, 250B1, 250B2, and 250C is not connected to the upper layer gas flow passage 263 that connects the gas outlet hole 261 of the first surface S1 and the gas inlet hole 262 of the second surface S2.

The upper gas flow path 263 includes an upper surface parallel portion 263T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), a first connection portion 263V1 connecting the gas outflow hole 261 provided on the first surface S1 to the upper surface parallel portion 263T, and a second connection portion 263V2 connecting the gas inflow hole 262 provided on the second surface S2 to the upper surface parallel portion 263T. The gas outflow hole 261 is formed in substantially the same manner as the gas outflow hole 61 according to the first embodiment, and the upper surface parallel portion 263T is formed in substantially the same manner as the upper surface parallel portion 63T according to the first embodiment. As shown in FIG. 6, the gas inflow hole 262 is formed inside one of the four intermediate zones BZ (the first intermediate zone B1Z at the lower left in FIG. 6). As shown in FIG. 7, the base member 220 is provided with an in-base flow passage 280 that connects the lower surface opening 281 and the gas inlet hole 262 provided on the third surface S3. In this embodiment, the thermally conductive gas introduced from the lower surface opening 281 flows directly into the upper gas flow passage 263 from the gas inlet hole 262 and reaches the upper surface parallel portion 263T through the second connection portion 263V2. As the gas circulating in the upper surface parallel portion 263T passes through the first intermediate zone B1Z and the second intermediate zone B2Z, the gas flows out from the gas outlet hole 261 and fills the gap between the first surface S1 and the wafer W.

The lower gas flow path 265 includes a lower surface parallel portion 265T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), and a lower connection portion 265V connecting the openings 264N, 264X provided on the second surface S2 to the lower surface parallel portion 265T. As shown in FIG. 6, the lower surface parallel portion 265T according to this embodiment is formed so as to surround each of the heating zones AZ, B1Z, B2Z, and CZ when viewed from above (when viewed from the first direction). The two openings 264N, 264X are provided directly below the positions adjacent to the three heating zones (first intermediate zone B1Z, second intermediate zone B2Z, and outer peripheral zone CZ) of the lower surface parallel portion 265T, sandwiching the center of the plate surface. As shown in FIG. 7, each of the openings 264N, 264X is connected to a base internal flow path 280 formed inside the base member 220 and communicates with a lower surface opening 281 provided on the third surface S3. Gas can flow in from one of the two openings 264N, 264X, and can flow out from the other opening 264X. That is, gas introduced into the lower gas flow path 265 from the lower surface opening 281 communicating with the opening 264N flows through the lower surface parallel portion 265T and the like inside the plate-shaped member 210, and then flows back to the third surface S3 side.

In addition, in the holding device 201, as shown in Figures 6 and 7, a common connection member (common driver electrode) 255 is formed inside the plate-like member 210, and the first intermediate heating element 250B1 and the second intermediate heating element 250B2 are connected to a common intermediate output terminal 293B via the common connection member 255. The common connection member 255 can be provided below the lower surface parallel portion 265T so as to span the first intermediate zone B1Z and the second intermediate zone B2Z. Figures 6 and 7 show that the intermediate output terminal 293B is arranged directly below one end of the second intermediate heating element 250B2, and one end 250B1T of the first intermediate heating element 250B1 is connected to the intermediate output terminal 293B via the common connection member 255. In this embodiment, the input side is not shared, and the other end of the first intermediate heating element 250B1 is connected to a first input terminal 291B1, and the other end of the second intermediate heating element 250B2 is connected to a second input terminal 291B2. Also, the inner peripheral input terminal 291A and the inner peripheral output terminal 293A are connected to the inner peripheral heating element 250A, and the outer peripheral input terminal 291C and the outer peripheral output terminal 293C are connected to the outer peripheral heating element 250C.

As in this embodiment, the upper gas flow passage 263 and the lower gas flow passage 265 can be formed independently of each other. In such a holding device 201, it is possible to flow a fluid, such as a gas (gas) or liquid different from that in the upper gas flow passage 263, in the lower gas flow passage 265, or to not flow a fluid in the lower gas flow passage 265. Even if no fluid is flowed in the lower gas flow passage 265, the lower surface parallel portion 265T is formed between each heating zone, so that heat transfer across the heating zones is reduced. When a fluid is flowed in the lower gas flow passage 265, a material with a lower thermal conductivity than the material forming the plate-shaped member 210 is used. Alternatively, a solid with a lower thermal conductivity than the material forming the plate-shaped member 210 may be placed in the lower gas flow passage 265.

Furthermore, as in this embodiment, some of the terminals connected to the heating elements arranged in each heating zone can be shared. By sharing the terminals, the structure of the base member 220 and the like can be simplified, and the number of required parts can be reduced. In this embodiment, since the lower surface parallel portion 265T is formed as a duct inside the plate-shaped member, it is possible to arrange the common connection member 255 below the lower surface parallel portion 265T so as to straddle the first intermediate zone B1Z and the second intermediate zone B2Z.

<Modification 2-1 of Second Embodiment>
A holding device 301 according to Modification 2-1 of Embodiment 2 will be described with reference to Figures 8 and 9. The holding device 301 according to this embodiment differs from the holding device 201 according to Embodiment 2 mainly in the structure of a lower layer gas flow passage 365 formed inside a plate-like member 310. Note that in this modification, the lower layer gas flow passage 365 is not connected to the upper layer gas flow passage 363.

The upper gas flow path 363 is basically of the same structure as the upper gas flow path 263 according to embodiment 2, and includes an upper surface parallel portion 363T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), a first connection portion 363V1 connecting the gas outflow hole 361 provided in the first surface S1 to the upper surface parallel portion 363T, and a second connection portion 363V2 connecting the gas inflow hole 362 provided in the second surface S2 to the upper surface parallel portion 363T.

The lower gas flow path 365 includes a lower surface parallel portion 365T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), and a lower connection portion 365V connecting the openings 364N and 364X provided on the second surface S2 to the lower surface parallel portion 365T. In this embodiment, unlike the second embodiment, as shown in Figures 8 and 9, two openings 364N for inflowing gas and two openings 364X for outflowing gas are formed in total, four openings. As shown in Figure 8, the openings 364N and the openings 364X are formed in the lower surface parallel portion 365T, one each in the portion extending in the circumferential direction between the inner zone AZ and the intermediate zone BZ, and one each in the portion extending in the circumferential direction between the intermediate zone BZ and the outer zone CZ. As shown in FIG. 9, each of the openings 364N, 364X is connected to an in-base flow path 380 formed inside the base member 320 and communicates with a lower surface opening 381 provided on the third surface S3. Gas introduced into the lower gas flow path 365 from the lower surface opening 381 communicating with the opening 364N flows through the lower surface parallel portion 365T and the like inside the plate-shaped member 310, and then flows back to the third surface S3 side.

By forming the lower gas flow passage 365 as in this modified example, gas can be steadily introduced into each of the portions of the lower surface parallel portion 365T that extend in the circumferential direction between the inner circumferential zone AZ and the intermediate zone BZ, and the portions that extend in the circumferential direction between the intermediate zone BZ and the outer circumferential zone CZ, allowing the gas to flow smoothly.

<Modification 2-2 of Second Embodiment>
A holding device 401 according to Modification 2-2 of Embodiment 2 will be described with reference to Figures 10 and 11. The holding device 401 according to this embodiment also differs from the holding device 201 according to Embodiment 2 mainly in the structure of a lower layer gas flow passage 465 formed inside a plate-like member 410. Note that in this modification, the lower layer gas flow passage 465 is not connected to the upper layer gas flow passage 463.

The upper layer gas flow path 463 is basically of the same structure as the upper layer gas flow path 263 according to embodiment 2, and includes an upper layer surface parallel portion 463T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), a first connection portion 463V1 connecting the gas outflow hole 461 provided in the first surface S1 to the upper layer surface parallel portion 463T, and a second connection portion 463V2 connecting the gas inflow hole 462 provided in the second surface S2 to the upper layer surface parallel portion 463T.

The lower gas flow path 465 includes a lower surface parallel portion 465T extending along a plane parallel to the first surface S1 (extending in a direction perpendicular to the first direction), and a lower connection portion 465V connecting the openings 464N, 464X provided on the second surface S2 to the lower surface parallel portion 465T. As shown in FIG. 11, the base member 420 is provided with a base inner flow path 480 that connects the lower surface opening 481 of the third surface S3 to the openings 464N, 464X. In this embodiment, unlike the second embodiment, the portion of the lower surface parallel portion 465T that extends in the circumferential direction between the outer peripheral zone CZ and the intermediate zone BZ shown in FIG. 10, and the portion that extends in the circumferential direction between the intermediate zone BZ and the inner peripheral zone AZ are formed to be connected in one direction, and the lower gas flow path 465 is structured so that gas flows as follows. Gas introduced from the lower surface opening 481 connected to the opening 464N flows from the opening 464N into the lower layer gas flow path 465, passes through the lower layer connection portion 465V, and reaches the lower layer parallel surface portion 465T. The gas that reaches the lower layer parallel surface portion 465T makes approximately one revolution counterclockwise between the outer peripheral zone CZ and the intermediate zone BZ, then flows toward the radial center and circulates clockwise between the intermediate zone BZ and the inner peripheral zone AZ. The gas that makes approximately one revolution and reaches the lower layer connection portion 465V while also flowing radially outward between the first intermediate zone B1Z and the second intermediate zone B2Z flows downward, passes through the base inner flow path 480 from the opening 464X, and flows out to the third surface S3 side from the lower surface opening 481.

By forming the lower layer gas flow passage 465 as in this modified example, gas can flow more smoothly within the lower layer parallel surface portion 465T.

<Other embodiments>
(1) In the above embodiment, the lower layer parallel surface portions corresponding to the voids in the claims are all described as ducts formed inside the plate-like member, but the present invention is not limited thereto. For example, as in the holding device 501 shown in FIG. 12, the lower layer parallel surface portion 565T that is connected to the upper layer parallel surface portion 63T via the lower layer connection portion 565V can be formed as a groove that opens on the second surface S2 of the plate-like member 510, unlike the holding device 1 according to the first embodiment. The lower layer parallel surface portion 565T having such a structure can be formed more easily by cutting a groove at a desired position on the second surface S2 as the final step when the plate-like member 510 is manufactured. Note that FIG. 12 shows a case in which the top surface of the lower layer parallel surface portion 565T in the plate-like member 510 is located below (on the second surface S2 side) the upper ends of the multiple heating elements 50.

(2) In the above embodiment, a single heating element is disposed within one heating zone, but this is not limiting. For example, multiple heating elements may be disposed within some or all of the heating zones. In addition, the arrangement pattern of the heating elements described in the above embodiment is merely an example, and heating elements may be disposed in a spiral or serpentine shape within each heating zone, for example.

(3) In the above embodiment, a case has been described in which an internal base flow path is formed inside the base member, which is connected to the gas inlet hole or opening formed in the plate-shaped member, but this is not limited to the above. In other words, the base member does not need to have a flow path formed therein. For example, a groove extending radially outward from the gas inlet hole may be formed on the second surface S2 of the plate-shaped member, and the end of this groove may be configured to open on the outer peripheral side surface of the holding device. Gas can be introduced through the opening on the outer peripheral side surface of the holding device. The present technology can also be applied to such a holding device to obtain the effects of the present technology.

(4) The base member is not limited to one having a refrigerant passage formed therein. It is preferable that the base member is formed of a material with high thermal conductivity and is equipped with a cooling mechanism such as a cooling fin.

(5) The above embodiments can be combined as appropriate. For example, in the plate-like member 10 described in embodiment 1, a common connection member as described in embodiment 2 can be provided to share the power supply terminals to the heating element.

(6) The materials used to form each component of the holding device in the above embodiment are merely examples, and each component may be formed from other materials. In addition, the manufacturing method for the holding device in the above embodiment is merely an example, and various modifications are possible.

(7) The present disclosure is not limited to the electrostatic chuck exemplified in the above embodiment, but is also applicable to other holding devices (e.g., heating devices, etc.) that hold an object on the surface of a ceramic substrate.

1, 101, 201, 301, 401, 501... Holding device 10, 110, 210, 310, 410, 510... Plate-shaped member 20, 120, 220, 320, 420... Base member 21... Coolant path 30... Bonding material 40... Chuck electrode 50... Heating element 50A, 250A... Inner peripheral heating element 50B1, 250B1... First intermediate heating element 250B1T... End portion 50B2, 250B2... Second intermediate heating element 50C, 250C... Outer peripheral heating element 55... Connection member (individual driver electrode)
255...common connection member (common driver electrode)
60... Gas flow path 61, 161, 261, 361, 461... Gas outflow hole 62, 162, 262, 362, 462... Gas inflow hole 264N, 264X, 364N, 364X, 4 64 N, 464
63V, 163V...upper layer connection portion 263V1, 363V1, 463V1...first connection portion (upper layer gas flow path)
263V2, 463V2, 463V2...Second connection portion (upper layer gas flow path)
65, 165, 265, 365, 465... Lower layer gas flow passage 65T, 165T, 265T, 365T, 465T... Lower layer parallel surface portion (void, pipe)
565T… Lower surface parallel part (empty space)
65V1, 165V1...first connection portion (lower layer gas flow path)
65V2, 165V2...Second connection part (lower gas flow path)
265V, 365V, 465V, 565V... Lower layer connection portion 80, 180, 280, 380, 480... Base inner flow passage 81, 181, 281, 381, 481... Lower surface opening 91, 93, 291, 293... Heater power supply terminal 91A, 291A... Inner circumference input terminal (input terminal)
91B1, 291B1...first input terminal (input terminal)
91B2, 291B2...Second input terminal (input terminal)
91C, 291C...Outer input terminal (input terminal)
93A, 293A...inner circumference output terminal (output terminal)
93B1: First output terminal (output terminal)
93B2: Second output terminal (output terminal)
293B: Intermediate output terminal (output terminal)
93C, 293C...Outer output terminal (output terminal)
264N, 264X, 364N, 364X, 464N, 464X...Open hole AZ...Inner peripheral zone (heating zone)
B1Z: First intermediate zone (heating zone)
B2Z: Second intermediate zone (heating zone)
CZ: Outer zone (heating zone)
S1: first surface S2: second surface S3: third surface W: wafer (object)

Claims (2)

a plate-like member having a first surface and a second surface perpendicular to a first direction;
a plurality of heating elements arranged at the same positions in the first direction on the plate-like member, the holding device holding an object on the first surface while heating the object,
The plate-like member includes:
a plurality of heating zones are provided, the heating zones being heated to different temperature ranges by the heating elements disposed therein as viewed from the first direction;
a void is formed between the plurality of heating zones as viewed from the first direction, and extends in a direction perpendicular to the first direction at the same position as the heating element in the first direction;
the void is a conduit provided inside the plate-like member,
a gas flow passage is formed in the plate-like member, the gas flow passage connecting a gas outlet hole provided in the first surface and a gas inlet hole provided in the second surface;
the gas flow path includes a plane-parallel flow path portion that is disposed closer to the first surface than the heating element in the first direction and extends in a direction perpendicular to the first direction,
The conduit is in communication with the gas flow path . The holding device according to claim 1 , wherein the cavity extends in the first direction beyond an end of the heating element on the second surface side toward the second surface side.

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