JP2022023284A - Holding device - Google Patents

Abstract

To provide a holding device with excellent temperature distribution controllability of a holding object.SOLUTION: The holding device of the present disclosure, comprises: a first heater pad 42A arranged in an outer peripheral region OR of a disc-like insulation plate 30, and connected to a first heater power supply terminal 80A via a connection member 60; a second heater pad 42B connected with a second heater power supply terminal 80B via the connection member 60; and a heater electrode 40 that is a resistor having a cross sectional area smaller than the first heater pad 42A and the second heater pad 42B, and contains a pair of heater lines 41A and 41B each of which is directly connected to the first heater pad 42A and the second heater pad 42B. When viewing the insulation plate 30 from a Z axial direction nearly orthogonal to a suction surface 30S1 holding an object, the first heater pad 41A and the second heater pad 41B are adjacent in a radial direction R directed to an outer periphery from a center C of the insulation plate 30, and the first heater pad 42A and the second heater pad 42B are arranged at a position where a distance from the center C becomes different.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a holding device for holding an object.

As an example of the holding device, an electrostatic chuck that holds a wafer when manufacturing a semiconductor is known. The electrostatic chuck includes an insulating plate having one plate surface as a suction surface and a chuck electrode provided inside the insulating plate, and utilizes electrostatic attraction generated by applying a voltage to the chuck electrode. Then, the wafer is sucked and held on the suction surface of the insulating plate.

If the temperature of the wafer held on the suction surface of the electrostatic chuck does not reach the desired temperature, the accuracy of each process (deposition, etching, etc.) on the wafer may decrease. Performance to control the temperature distribution of the wafer is required. For example, Patent Document 1 below discloses a holding device in which a plurality of heater electrodes are arranged inside an insulating plate. Each heater electrode has a linear heater line portion and a heater pad portion connected to an end portion of the heater line portion, and is electrically connected to a power feeding terminal. When a voltage is applied through the feeding terminal, each heater electrode heats up and the insulating plate is heated, and the temperature distribution of the adsorption surface of the insulating plate is controlled (and the temperature distribution of the wafer held on the adsorption surface is controlled). It will be realized.

JP-A-2019-125663

Of the heater electrodes, the heater pad connected to the power supply terminal draws a large amount of heat through the power supply terminal, and the amount of heat generated when a voltage is applied is smaller than that of the heater line. Therefore, the portion of the adsorption surface of the insulating plate corresponding to the heater pad becomes a low temperature temperature singular point, which may adversely affect the control of the temperature distribution.

An object of the technique disclosed in the present specification is to provide a holding device having excellent temperature distribution controllability of a holding object.

The holding device of the present disclosure includes a disk-shaped insulating plate having a first surface substantially orthogonal to the first direction, a heater electrode arranged on the insulating plate, and the first surface of the insulating plate. A holding device provided with a first feeding terminal and a second feeding terminal connected to the heater electrode and arranged on a surface opposite to the above, and holding an object on the first surface. The insulating plate is divided into a plurality of regions including a ring-shaped outer peripheral region including the outer peripheral edge of the insulating plate and an inner peripheral region located inside the outer peripheral region when viewed from the first direction. The heater electrode is arranged in the outer peripheral region and is connected to the first power feeding terminal via a connecting member, and is arranged in the outer peripheral region and is connected to the second feeding terminal via the connecting member. A connected second heater pad and a resistor having a cross-sectional area smaller than that of the first heater pad and the second heater pad, which are arranged in the outer peripheral region, respectively, are the first heater pad and the second heater pad, respectively. The first heater line and the second heater line constituting the pair of heater lines, including a pair of heater lines directly connected to the heater pad, and the insulating plate viewed from the first direction, are insulated. A holding device in which the first heater pad and the second heater pad are arranged so as to be adjacent to each other in the radial direction from the center of the plate toward the outer periphery, and the distances from the center of the insulating plate are different from each other. be.

According to the present disclosure, it is possible to provide a holding device having excellent temperature distribution controllability of a holding object.

FIG. 1 is a perspective view schematically showing a schematic configuration by breaking a part of a holding device according to an embodiment. FIG. 2 is a cross-sectional view schematically showing an outline of an example of the internal structure of the holding device. FIG. 3 is an explanatory diagram schematically showing an arrangement pattern of heater electrodes in a heater member when viewed from the Z-axis direction. FIG. 4 is a partially enlarged cross-sectional view showing an enlarged outer peripheral region portion of FIG. 2. FIG. 5 is an explanatory diagram schematically showing an arrangement pattern of heater electrodes in the heater member according to another embodiment.

[Explanation of Embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described.
<1> The holding device of the present disclosure includes a disk-shaped insulating plate having a first surface substantially orthogonal to the first direction, a heater electrode arranged on the insulating plate, and the first of the insulating plates. A holding device provided on a surface opposite to the surface 1 and provided with a first power supply terminal and a second power supply terminal connected to the heater electrode, and holding an object on the first surface. The insulating plate is divided into a plurality of regions including an outer peripheral region including the outer peripheral edge of the insulating plate and an inner peripheral region located radially inside the outer peripheral region when viewed from the first direction. The heater electrodes are arranged in the outer peripheral region and connected to the first power feeding terminal via a connecting member, and the second heater pad is arranged in the outer peripheral region and the second feeding power is supplied via the connecting member. A second heater pad connected to a terminal and a resistor having a cross-sectional area smaller than that of the first heater pad and the second heater pad, which are arranged in the outer peripheral region, respectively, the first heater pad and the second heater pad. The first heater line and the second heater line constituting the pair of heater lines, including the pair of heater lines directly connected to the second heater pad, when the insulating plate is viewed from the first direction, are The first heater pad and the second heater pad are arranged so as to be adjacent to each other in the radial direction from the center of the insulating plate toward the outer circumference, and the first heater pad and the second heater pad are arranged at different distances from the center of the insulating plate. It is a device.

In the above, the "disk-shaped" is not limited to the one in which the plate surface is a perfect circle, but includes the one having a substantially disk-like shape, that is, the substantially disk-shaped one, and the "directly connected" means via another member. It means that they are in contact with each other. Further, the “cross-sectional area” refers to the cross-sectional area when the heater electrodes are cut on a plane orthogonal to the line length direction of the pair of heater lines. According to the above configuration, the pair of heater lines adjacent to each other in the radial direction are connected in parallel by being directly connected to the first heater pad and the second heater pad, respectively. Therefore, the number of heater pads required to arrange a predetermined number of heater lines can be reduced. Further, the first heater pad and the second heater pad, which are parallel connection points, have different distances from the center of the first surface forming a circle when the insulating plate is viewed from the first direction, that is, in the radial direction. By being arranged at the shifted position, the first surface for holding the object is distributed and arranged. As a result, it is possible to reduce the possibility that the heater pads are close to each other and amplify the influence of the temperature singularity, and improve the controllability of the temperature distribution on the first surface of the insulating plate and the temperature distribution of the object. can. This technique is particularly useful in the outer peripheral region, which is susceptible to printing misalignment when the heater electrode is formed by printing.

<2> In the holding device of <1>, the first heater pad and the second heater pad refer to the insulating plate in the circumferential direction along the outer peripheral edge of the insulating plate when viewed from the first direction. It is preferably arranged in a shifted position. In such a configuration, the first heater pad and the second heater pad, which are parallel connection points of the pair of heater lines, are positioned so as to be shifted not only in the radial direction but also in the circumferential direction when viewed from the first direction. Will be distributed. Therefore, the heater pads are further dispersed and arranged on the first surface for holding the object. As a result, the influence of the temperature singularity is dispersed, and it becomes difficult to locally control the temperature of the object.

<3> In the holding device of <1> or <2>, the first heater line and the second heater line have at least three in the radial direction when the insulating plate is viewed from the first direction. It is preferable that they are arranged so as to be alternately adjacent to each other. In such a configuration, the first heater line and the second heater line connected in parallel between the first heater pad and the second heater pad are arranged so that different heater lines are adjacent to each other in the radial direction. In other words, in the radial direction, when two first heater lines are arranged, one second heater line is arranged between them and two second heater lines are arranged between them. If so, one first heater line is arranged between them. With such an arrangement, even if at least one of the first heater line and the second heater line is formed to have a resistance different from the design value, the heater lines having the same resistance are connected to each other. However, the influence is not amplified adjacently, and the possibility that temperature control becomes difficult locally can be reduced. In particular, in the outer peripheral region where the heater electrode is easily affected by printing misalignment when the heater electrode is formed, at least one of the first heater line and the second heater line is formed so as to have a resistance different from the design value. Even if the other heater lines having different resistances are arranged adjacent to each other, the influence is canceled out and it is less likely that the temperature control becomes difficult locally.

[Details of the embodiment]
An example of the embodiment of the holding device of the present disclosure will be specifically described below with reference to FIGS. 1 to 4. The present disclosure is not limited to illustrations, but is shown by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. A part of each drawing shows the X-axis, the Y-axis, and the Z-axis of the Cartesian coordinate system XYZ, and each axis direction is drawn so as to be the same direction in each drawing. In the following, the Z-axis direction is the vertical direction, the upper side of FIG. 2 is the upper side, and the lower side of FIG. 2 is the lower side. Further, for a plurality of the same members, one member may be designated with a reference numeral and the reference numerals of the other members may be omitted.

<Electrostatic chuck>
In this embodiment, an electrostatic chuck (an example of a holding device) 10 is exemplified as a holding device. The electrostatic chuck 10 is a holding device that attracts and holds a semiconductor wafer, a glass substrate, or the like (hereinafter referred to as “wafer (an example of an object) 100”) which is an object (work) by electrostatic attraction. The electrostatic chuck 10 is used as a table on which the wafer 100 is placed, for example, in a process of etching using plasma in a depressurized chamber.

FIG. 1 is a diagram schematically showing an outline of the configuration of the electrostatic chuck 10. The electrostatic chuck 10 includes a disk-shaped heater member 20 and a disk-shaped base member 90. The base member 90 is larger than the heater member 20, for example, when the heater member 20 has a disk shape having a diameter of 300 mm and a thickness of 3 mm, the base member 90 can have a disk shape having a diameter of 340 mm and a thickness of 20 mm. Both the heater member 20 and the base member 90 may be substantially disk-shaped, and may be provided with irregularities or the like for positioning. The base member 90 and the heater member 20 are arranged in the Z-axis direction and are joined by a bond material 70 or the like. The upper surface of the disk-shaped insulating plate 30 constituting the heater member 20 is a suction surface (corresponding to the first surface) 30S1 that sucks and holds the wafer 100, and the lower surface of the insulating plate 30 is joined to the base member 90. The joint surface (corresponding to the opposite surface) is 30S2.

FIG. 2 is a cross-sectional view when the electrostatic chuck 10 is cut on a surface perpendicular to the suction surface 30S1 including the first radius RA and the second radius RB, which will be described later, and is an example of the internal structure of the electrostatic chuck 10. The outline is shown schematically. Further, FIG. 3 schematically shows an arrangement pattern of the heater electrodes 40 when the insulating plate 30 is viewed from the Z-axis direction.

The suction surface 30S1 is a plate surface facing upward of the disk-shaped insulating plate 30, is a plane having a normal Z axis as shown in FIG. 2, and is viewed from the Z axis direction as shown in FIG. Make a circle. The first surface may be substantially circular, and may be partially provided with a notch or the like.

In the present embodiment, the Z-axis direction (vertical direction) is the first direction. Further, as shown in FIG. 2, the line passing through the center C of the suction surface 30S1 and parallel to the Z axis is defined as the center line CL, and as shown in FIG. 3, when the insulating plate 30 is viewed from the Z axis, the center C is used. The direction from to the outer circumference is defined as the radial direction R.

The suction surface 30S1 is a circular surface having a center C when viewed from the first direction, and is a surface substantially orthogonal to the first direction. The suction surface 30S1 may be provided with irregularities. Further, the joint surface 30S2 is a plate surface facing downward of the disk-shaped insulating plate 30, and is a surface provided on the side opposite to the suction surface 30S1 of the insulating plate 30 in the first direction.

As shown in FIGS. 2 and 3, the insulating plate 30 is located inside the ring-shaped outer peripheral region OR, which includes the outer peripheral edge and is located outside in the radial direction R, and the outer peripheral region OR, when viewed from the Z-axis direction. It is divided into a circular inner peripheral region IR and the like. The boundary between the outer peripheral region OR and the inner peripheral region IR can be provided, for example, at a position where the distance from the center is 0.6 to 0.9 times the radius in the radial direction R. In addition, in FIG. 2 and FIG. 4, the case where the outer peripheral region OR and the inner peripheral region IR are separated by the ring connecting the pore edges of the ejection port 32 arranged on the suction surface 30S1 as a boundary is exemplified. However, the boundary is not limited to this, and the boundary between the outer peripheral region OR and the inner peripheral region IR can be arbitrarily set. Further, the inner peripheral region IR may be further divided into a plurality of regions including, for example, a ring-shaped intermediate region and an inner region inside the intermediate region.

As shown in FIGS. 1 and 2, the bond material 70 is arranged between the joint surface 30S2 of the heater member 20 and the upper surface of the base member 90. The bond material 70 can be formed of an adhesive material containing an adhesive material such as a silicone resin, an acrylic resin, or an epoxy resin as a main component. The bond material 70 has a function of adhering the insulating plate 30 and the base member 90, contributing to heat conduction between the two members, and relaxing the stress caused by the difference in the thermal expansion rate of the two members.

As shown in FIGS. 1 and 2, the electrostatic chuck 10 is formed with a pin insertion hole 11 that penetrates both the insulating plate 30 constituting the heater member 20 and the base member 90 in the vertical direction. A lift pin is inserted through the pin insertion hole 11, and the wafer 100 can be lifted from the suction surface 30S1 by moving the lift pin upward.

<Heater member>
As shown in FIGS. 1 and 2, the heater member 20 includes a disk-shaped insulating plate 30 and has a function of heating the wafer 100 held on the suction surface 30S1 to a predetermined temperature. In the present embodiment, the heater electrode 40 is arranged inside the insulating plate 30. The heater electrode 40 may be provided on the joint surface 30S2 of the insulating plate 30. Inside the insulating plate 30, a chuck electrode 50 is also arranged between the heater electrode 40 and the suction surface 30S1.

As the insulating plate 30, in the present embodiment, for example, an insulator made of alumina, aluminum nitride, ytria, or an insulator containing a ceramic containing a composite material of alumina and silicon carbide as a main component is used. In addition to ceramic, the insulating plate 30 may be made of an insulator containing polyimide, pyrolysis boron nitride (PBN), or the like.

The insulating plate 30 has a disk shape as described above, and has a suction surface 30S1 substantially orthogonal to the first direction (Z-axis direction). Further, as shown in FIGS. 1 and 2, a gas flow path 31 through which a gas such as helium flows is formed inside the insulating plate 30 according to the present embodiment. The gas flow path 31 includes a vertical hole and a horizontal hole, and the ejection port 32 communicating with the gas flow path 31 is arranged in an annular shape on the suction surface 30S1. When gas is supplied to the gas flow path 31 from a gas supply source (not shown), the gas discharged from the ejection port 32 via the vertical hole and the horizontal hole is introduced into the space between the wafer 100 and the insulating plate 30. Will be done. As a result, the heat conduction between the wafer 100 and the insulating plate 30 is improved, and the temperature controllability of the wafer 100 by the heater member 20 is improved. The insulating plate 30 may not have a gas flow path, or may have a gas flow path composed of only vertical holes.

The heater electrode 40 generates heat when a voltage is applied. The heater electrode 40 can be composed of tungsten, molybdenum, an alloy thereof, or a carbide thereof as a main component. In the present embodiment, as the heater electrode 40, metallizing in which a conductor paste is printed and the conductor layer is sintered is used. The heater electrode 40 is not limited to such a thing, and a metal foil, a metal mesh, or the like may be used as the heater electrode 40. The heater electrode 40 will be described later.

The chuck electrode 50 exhibits an electrostatic adsorption force when a voltage is applied. As the type of electrostatic adsorption force, Coulomb force, Johnsen-Labeck force, gradient force and the like can be used. The chuck electrode 50 can be composed of tungsten, molybdenum, or an alloy thereof as a main component. In this embodiment, a case where a metallize in which a conductor layer printed with a conductor paste is sintered is used as the chuck electrode 50 is illustrated. A metal foil, a metal mesh, or the like may be used as the chuck electrode 50.

As shown in FIGS. 1 and 2, in the heater member 20, the chuck electrode 50 is arranged inside the insulating plate 30 side by side with the heater electrode 40 in the vertical direction. The chuck electrode 50 is arranged on the upper side near the suction surface 30S1, and the heater electrode 40 is arranged on the lower side of the chuck electrode 50. Further, inside the insulating plate 30, a connecting member 60 is arranged on the lower side of the heater electrode 40, and a connecting member 69 is arranged on the lower side of the chuck electrode 50. The heater electrode 40 is connected to the heater feeding terminal 80 described later via the connecting member 60, and the chuck electrode 50 is connected to the chuck feeding terminal 89 described later via the connecting member 69. The connecting member 60 will be described later.

As the heater member 20, in the present embodiment, a member manufactured by integrating a plurality of ceramic sheets is used. In order to form the gas flow path 31, the heater electrode 40, the chuck electrode 50, etc. described above, first, perforations and conductive materials are applied to each of the plurality of ceramic sheets according to a predetermined pattern peculiar to each ceramic sheet. Etc. are applied. After that, a plurality of processed ceramic sheets are laminated in the Z-axis direction and integrated through processes such as thermocompression bonding, cutting, and firing.

<Base member>
The base member 90 can be composed of aluminum, an aluminum alloy, a composite of metal and ceramics (Al—SiC), or ceramics (SiC) as a main component. As described above, the base member 90 has a disk shape and has a larger diameter than the heater member 20 so that the entire heater member 20 can be placed on the base member 90.

As shown in FIGS. 1 and 2, a gas introduction path 91 communicating with the gas flow path 31 of the insulating plate 30 and a refrigerant flow path 92 are formed inside the base member 90. A refrigerant such as water or a fluorine-based inert liquid flows through the refrigerant flow path 92. When the refrigerant flows through the refrigerant flow path 92, the base member 90 is cooled, the insulating plate 30 is cooled by heat conduction via the bond material 70, and the wafer 100 held on the suction surface 30S1 of the insulating plate 30 is cooled. To. The temperature of the wafer 100 is controlled by adjusting the flow of the refrigerant.

As shown in FIGS. 1 and 2, inside the base member 90, a heater feeding terminal 80 and a chuck feeding terminal 89 are arranged so as to penetrate the base member 90 in the vertical direction. The feeding terminals 80 and 89 can be formed of, for example, a metal such as nickel (Ni). The lower ends of the power feeding terminals 80 and 89 are exposed on the lower surface of the base member 90 and are connected to a power source (not shown). Further, the upper ends of the feeding terminals 80 and 89 are exposed on the upper surface of the bond material 70, the heater feeding terminal 80 is connected to the heater electrode 40 via the connecting member 60, and the chuck feeding terminal 89 is connected to the chuck electrode 50 via the connecting member 69. Are connected to each other. As a result, the electric power from each power source can be supplied to the heater electrode 40 and the chuck electrode 50 through the heater feeding terminal 80 and the chuck feeding terminal 89.

When the electrostatic chuck 10 is used, the electric power from the power source for the chuck is supplied to the chuck electrode 50 via the chuck feeding terminal 89. As a result, a voltage is applied to the chuck electrode 50 to generate an electrostatic adsorption force that adsorbs the wafer 100, and the electrostatic adsorption force holds the wafer 100 on the adsorption surface 30S1. Further, when processing such as etching is performed, electric power from the power source for the heater is supplied to the heater electrode 40 via the heater feeding terminal 80. As a result, a voltage is applied to the heater electrode 40 to generate heat, the temperature of the insulating plate 30 rises, and the wafer 100 held on the suction surface 30S1 is heated.

<Structure of heater electrode>
The heater electrode 40 will be described again. In the present embodiment, among the plurality of ceramic sheets forming the insulating plate 30 described above, the metallizing in which the conductor paste is printed on a specific ceramic sheet and the conductor layer is sintered is used as the heater electrode 40. Therefore, the heater electrode 40 is arranged in the heater electrode layer substantially parallel to the suction surface 30S1 inside the insulating plate 30.

The heater electrode layer is divided into a portion included in the outer peripheral region OR of the insulating plate 30 and a portion included in the inner peripheral region IR, and the heater electrode 40 is arranged for each region. Hereinafter, the configuration and arrangement of the heater electrode 40 in the outer peripheral region OR will be described mainly with reference to FIGS. 3 and 4. FIG. 4 is a partially enlarged view of FIG. 2, and schematically shows the internal structure of the electrostatic chuck 10 in the outer peripheral region OR of the cross section including the first radius RA and the second radius RB, which will be described later. The heater electrode 40 in the inner peripheral region IR basically has the same configuration as the heater electrode 40 in the outer peripheral region OR. The arrangement of the heater electrodes 40 in the inner peripheral region IR does not matter. In the inner peripheral region IR, the heater electrode 40 may be arranged in the same manner as the heater electrode 40 in the outer peripheral region OR, or may be arranged in a different manner.

As shown in FIGS. 3 and 4, the heater electrode 40 includes a heater line 41 which is a linear resistor and a heater pad 42 formed at an end portion of the heater line 41.

As shown in FIG. 3, the heater line 41 has a linear shape when viewed from the Z-axis direction, and extends in an annular shape along the circumferential direction I as a whole in the heater electrode layer. As will be described later with reference to FIG. 4, the heater line 41 has a relatively small line width W1 in a cross section cut along a plane (a plane including the center line CL and a radius) orthogonal to the line length direction (circumferential direction I). It is formed so that the cross-sectional area multiplied by the thickness T is relatively small. When electric power is supplied to the heater electrode 40 and a voltage is applied to the heater line 41, the heater line 41 generates heat according to the cross-sectional area, the temperature of the insulating plate 30 rises, and the temperature of the wafer 100 is controlled.

As shown in FIG. 3, the heater pad 42 has, for example, a substantially circular shape when viewed from the Z-axis direction, and is directly connected to the end of the heater line 41 without any other member. As shown in FIG. 4, the heater pad 42 has a thickness T substantially equal to that of the heater line 41, and the diameter W2 seen from the Z-axis direction is formed to be larger than the line width W1 of the heater line 41. Therefore, the heater pad 42 has a larger cross-sectional area cut along the plane orthogonal to the line length direction of the heater line 41 than the heater line 41. Electric power is supplied from the heater feeding terminal 80 through the heater pad 42, and a voltage is applied to the heater line 41.

<Structure for supplying power to the heater electrode>
As shown in FIG. 2, a heater feeding terminal 80 is arranged below the heater pad 42. The heater pad 42 and the heater feeding terminal 80 are electrically connected via a conductive connecting member 60. As shown in FIG. 4, for example, the connection member 60 includes an intermediate connection pad 62 arranged below the heater pad 42 and a terminal exposed to the joint surface 30S2 below the intermediate connection pad 62 and joined to the heater power supply terminal 80. It is composed of a pad 64, an electrode side connecting via 61 joined to the heater pad 42 and the intermediate connecting pad 62, and a terminal side via 63 joined to the intermediate connecting pad 62 and the terminal pad 64. The connecting member 60 is not limited to such a configuration, and may have, for example, a plurality of intermediate connecting pads, and the connecting members 60 may be connected by intermediate connecting vias.

<Arrangement of heater electrodes, etc.>
As shown in FIGS. 3 and 4, in the present embodiment, a pair of heater lines 41A and 41B composed of a first heater line 41A and a second heater line 41B are arranged as heater lines 41 in the outer peripheral region OR. .. Similarly, the first heater pad 42A and the second heater pad 42B are arranged as the heater pad 42 in the outer peripheral region OR.

Further, as shown in FIG. 4, in the portion of the base member 90 that is superimposed on the outer peripheral region OR of the insulating plate 30, the first heater feeding terminal 80A connected to the first heater pad 42A and the second heater pad are located. A second heater feeding terminal 80B connected to 42B is arranged. As shown in FIG. 4, when the insulating plate 30 is viewed from the Z-axis direction, the first heater feeding terminal 80A is superimposed on the first heater pad 42A, and the second heater feeding terminal 80B is superimposed on the second heater pad 42B.

As shown in FIG. 3, in the present embodiment, both ends of the first heater line 41A and the second heater line 41B are directly connected to the first heater pad 42A or the second heater pad 42B without interposing other members. It is connected. The heater lines 41A and 41B and the heater pads 42A and 42B can be formed in this way by printing and forming them on a ceramic sheet as an integral pattern. As a result, the pair of heater lines 41A and 41B are connected in parallel between the first heater pad 42A and the second heater pad 42B.

As shown in FIG. 3, when the insulating plate 30 is viewed from the Z-axis direction, the distance DA of the first heater pad 42A to the center C of the insulating plate 30 is the distance from the second heater pad 42B to the center C. It is arranged at a position different from the DB (DA ≠ DB), specifically, at a position where the distance DA is larger than the distance DB (DA> DB). In other words, the first heater pad 42A and the second heater pad 42B are arranged at positions shifted from each other in the radial direction R. Further, in the present embodiment, when the insulating plate 30 is viewed from the Z-axis direction, the first heater pad 42A is not located on the same radius as the second heater pad 42B, but has a first radius passing through the first heater pad 42A. The central angle θ formed by RA and the second radius RB passing through the second heater pad 42B is larger than 0 ° (0 ° <θ). In other words, the first heater pad 42A and the second heater pad 42B are arranged at positions shifted from each other in the circumferential direction I. Specifically, θ preferably satisfies 0 ° <θ <90 °, more specifically 0 ° <θ <45 °, and can be, for example, θ≈20 °. By arranging the first heater pad 42A and the second heater pad 42B so that θ becomes such a value, the present technology can be applied more effectively.

As shown in FIG. 3, in the present embodiment, four of the pair of heater lines 41A and 41B are arranged in the radial direction R, and the first heater line 41A and the second heater line 41B are alternately adjacent to each other in parallel. It is arranged to go around while. Specifically, as shown in FIG. 3, from the center line CL toward the outer peripheral edge of the insulating plate 30 (that is, about the radial direction R from the center C of the insulating plate 30 viewed from the Z-axis direction toward the outer peripheral edge). The first heater line 41A, the second heater line 41B, the first heater line 41A, and the second heater line 41B are arranged in this order.

The arrangement pattern of the pair of heater lines 41A, 41B, etc. shown in FIG. 3 will be described in more detail. The first heater pad 42A is arranged near the outer peripheral edge on the first radius RA. The first heater line 41A connected to the first heater pad 42A extends as it is along the outer peripheral edge so as to draw an arc (counterclockwise in FIG. 3). On the other hand, the second heater line 41B connected to the same first heater pad 42A is bent to the inner peripheral side by a predetermined amount and then turned, and maintains a predetermined interval on the inner peripheral side of the first heater line 41A. However, in parallel, they are extended in an arc (counterclockwise in FIG. 3). The pair of heater lines 41A and 41B that circulate in parallel along the outer peripheral edge are bent to the inner peripheral side by a predetermined amount after passing through the second radius RB and before reaching the first radius RA. Then, the direction is changed at a position where the distance between the second heater line 41B arranged on the inner peripheral side and the center C is substantially equal to the distance DB between the second heater pad 42B and the center C, and the predetermined distance is maintained again. At the same time, they are extended in parallel (counterclockwise in FIG. 3) in an arc. Of the pair of heater lines 41A and 41B, the second heater line 41B located on the inner peripheral side reaches and is connected to the second heater pad 42B while drawing an arc as it is. On the other hand, the first heater line 41A located on the outer peripheral side is connected to the second heater pad 42B after being bent inward in the vicinity of the second radius RB.

In the arrangement pattern as shown in FIG. 3, the pair of heater lines 41A and 41B draw a step in a fan shape having a central angle θ defined by the first radius RA and the second radius RB. In parallel, in the area excluding the fan shape, four are arranged so as to draw a parallel arc along the outer peripheral edge. Then, in the radial direction R, the first heater line 41A and the second heater line 41B are always arranged so as to be adjacent to each other. That is, in the radial direction R, the first heater lines 41A or the second heater lines 41B are not adjacent to each other, and the second heater line 41B is arranged between the two first heater lines 41A. A first heater line 41A is arranged between the two second heater lines 41B. Further, the length of the first heater line 41A connecting between the first heater pad 42A and the second heater pad 42B and the length of the second heater line 41B are substantially equal to each other.

<Effect of this embodiment>
As described above, the electrostatic chuck (an example of the holding device) 10 of the present embodiment has a suction surface (corresponding to the first surface) 30S1 substantially orthogonal to the Z-axis direction (an example of the first direction). A disk-shaped insulating plate 30 having a (Equivalent to) 30S2 is provided with a first heater feeding terminal (an example of a first feeding terminal) 80A and a second heater feeding terminal (an example of a second feeding terminal) 80B connected to the heater electrode 40, and is adsorbed. A holding device for holding a wafer (an example of an object) 100 on the surface 30S1, wherein the insulating plate 30 has an outer peripheral region OR including an outer peripheral edge of the insulating plate 30 and an outer peripheral region OR when viewed from the Z-axis direction. The heater electrode 40 is divided into a plurality of regions including an inner peripheral region IR located on the inner side in the radial direction, the heater electrode 40 is arranged in the outer peripheral region OR, and is connected to the first heater feeding terminal 80A via a connecting member 60. The 1 heater pad 42A, the second heater pad 42B arranged in the outer peripheral region OR and connected to the second heater power supply terminal 80B via the connecting member 60, and the second heater pad 42A and the second heater pad 42B are cut off from each other. A resistor having a small area, including a pair of heater lines 41 arranged in the outer peripheral region OR, each of which is directly connected to the first heater pad 42A and the second heater pad 42B, and the insulating plate 30 on the Z axis. When viewed from the direction, the first heater line 41A and the second heater line 41B constituting the pair of heater lines 41 are arranged so as to be adjacent to each other in the radial direction R from the center C of the insulating plate 30 toward the outer circumference. The pad 42A and the second heater pad 42B are arranged at positions where the distances DA and DB from the center C of the insulating plate 30 are different.

According to the above configuration, the first heater line 41A and the second heater line 41B adjacent to each other in the radial direction R are connected in parallel by being directly connected to the first heater pad 42A and the second heater pad 42B, respectively. .. Therefore, the number of heater pads 42 required to arrange a predetermined number of heater lines 41 can be reduced. Further, the first heater pad 42A and the second heater pad 42B, which are parallel connection points, have different distances DA and DB to the center C of the circular suction surface 30S1 when the insulating plate 30 is viewed from the Z-axis direction. That is, by being arranged at a position shifted in the radial direction R, the suction surface 30S1 holding the wafer 100 is dispersedly arranged. As a result, the possibility that the heater pads 42 are close to each other and the influence of the temperature singularity is amplified is reduced, the temperature distribution on the suction surface 30S1 of the insulating plate 30, and the temperature of the wafer 100 held on the suction surface 30S1. It is possible to improve the controllability of the distribution. This technique is particularly useful in the outer peripheral region OR, which is susceptible to printing misalignment when the heater electrode 40 is formed by printing.
When the insulating plate 30 is viewed from the Z-axis direction and the central angle θ formed by the first radius RA and the second radius RB is in the range of 0 ° ≦ θ ≦ 90 °, specifically, 0 ° < When θ <90 °, more specifically, 0 ° <θ <45 °, the dispersion effect by shifting the first heater pad and the second heater pad in the radial direction becomes large. Therefore, this technique can be applied particularly effectively in such a range.

Further, in the present embodiment, the first heater pad 42A and the second heater pad 42B are arranged at positions shifted with respect to the circumferential direction I along the outer peripheral edge of the insulating plate 30 when the insulating plate 30 is viewed from the Z-axis direction. ing. In such a configuration, the first heater pad 42A and the second heater pad 42B, which are parallel connection points of the pair of heater lines 41, are not only in the radial direction R but also in the circumferential direction I when viewed from the Z-axis direction. It is placed in the shifted position. Therefore, the heater pads 42 are further dispersed and arranged on the suction surface 30S1 that holds the wafer 100. As a result, the influence of the temperature singularity is dispersed, and it becomes difficult for the temperature control of the wafer 100 to become difficult locally.

Further, in the present embodiment, the first heater line 41A and the second heater line 41B are arranged so that four insulating plates 30 are alternately adjacent to each other in the radial direction R when the insulating plate 30 is viewed from the Z-axis direction. In such a configuration, the first heater line 41A and the second heater line 41B connected in parallel between the first heater pad 42A and the second heater pad 42B have different heater lines 41 adjacent to each other in the radial direction R. Arranged. That is, in the radial direction R, the same heater lines are not adjacent to each other, and one second heater line is arranged between the two first heater lines 41A, and the two second heater lines 41B are arranged. One first heater line is arranged between them. With such an arrangement, even if at least one of the first heater line 41A or the second heater line 41B is formed to have a resistance different from the design value, the heater having the same resistance Since the lines 41 are adjacent to each other and the influence is not amplified, the possibility that the temperature control becomes difficult locally can be reduced. In particular, in the outer peripheral region OR which is easily affected by printing misalignment when the heater electrode 40 is formed by printing, it is assumed that at least one of the first heater line 41A and the second heater line 41B has a resistance different from the design value. Even if they are formed, the influence is canceled by arranging the other heater lines 41 having different resistances adjacent to each other, and it is less likely that the temperature control becomes difficult locally.
In this embodiment, since the heater electrodes 40 are arranged as shown in FIG. 3, the lengths of the first heater line 41A and the second heater line 41B connected in parallel are substantially the same. Therefore, it is possible to make the heat generation amounts of both the heater lines 41A and 41B substantially the same by setting the first heater line 41A and the second heater line 41B to have the same line width W1. As a result, the design for uniformly heating the suction surface 30S1 of the insulating plate 30 becomes easy.

[Modification example]
A modified example of the embodiment of the holding device of the present disclosure will be described with reference to FIG. In this modification, only the arrangement pattern of the heater electrode 140 including the heater line 141 and the heater pad 142 is different from the above-described embodiment. In the following, only the heater electrode 140 different from the embodiment will be described, and the description of the same configuration will be omitted.

As shown in FIG. 5, in the heater member 120 according to the present modification, the pair of heater lines 141A and 141B composed of the first heater line 141A and the second heater line 141B arranged in the outer peripheral region OR are the first heaters. It is assumed that heat is generated by being connected in parallel between the pad 142A and the second heater pad 142B and applying a voltage from a heater feeding terminal electrically connected to the heater pads 142A and 142B. Further, the first heater pad 142A and the second heater pad 142B are provided at positions shifted from each other in the radial direction R and the circumferential direction I. Specifically, the distance DA between the first heater pad 142A and the center C is larger than the distance DB between the second heater pad 142B and the center C (DA> DB), and the first radius RA passing through the first heater pad 142A. The central angle θ formed by the second radius RB passing through the second heater pad 142B is larger than 0 ° (θ> 0 °). In this modification, for example, θ≈10 °.

In the arrangement pattern of the present modification shown in FIG. 5, the first heater line 141A connected to the first heater pad 142A arranged near the outer peripheral edge on the first radius RA is directly along the outer peripheral edge in FIG. It is extended so as to draw an arc clockwise in. On the other hand, the second heater line 141B connected to the first heater pad 142A is bent to the inner peripheral side by a predetermined amount and then turned, while maintaining a predetermined interval on the inner peripheral side of the first heater line 141A. In parallel, it is extended so as to draw an arc clockwise in FIG. The pair of heater lines 141A and 141B that circulate in parallel along the outer peripheral edge are bent toward the inner peripheral side immediately before reaching the first radius RA. The first heater line 141A is turned counterclockwise at a position where the distance from the center C is substantially equal to the distance DB between the second heater pad 142B and the center C, and the second heater line 141B is the first. It is turned in the same direction as the heater line 141A so as to maintain a predetermined distance, and is extended again in parallel in a counterclockwise arc. Of the pair of heater lines 141A and 141B, the first heater line 141A located on the inner peripheral side reaches and is connected to the second heater pad 142B while drawing an arc as it is. On the other hand, the second heater line 141B located on the outer peripheral side is connected to the second heater pad 142B after being bent inward in the vicinity of the second radius RB. As a result, four of the pair of heater lines 141A and 141B are adjacent to each other in the radial direction R, and from the inner peripheral side, the first heater line 141A, the second heater line 141B, the second heater line 141B, and the first heater line 141A are adjacent to each other. , Are arranged in this order.

Also in this modification, the first heater pad 142A and the second heater pad 142B are arranged at different positions of the distances DA and DB from the center C of the insulating plate 30 when viewed from the Z-axis direction. Further, the first heater pad 142A and the second heater pad 142B are arranged at positions shifted from each other in the circumferential direction I.
According to such a configuration, the heater pads 142A and 142B are dispersed and arranged on the suction surface 30S1 holding the wafer 100. As a result, the influence of the temperature singularity is dispersed, and it is difficult to locally control the temperature of the wafer 100.

[Other embodiments]
(1) The arrangement positions of the heater pads shown in FIGS. 3 and 5 are merely examples, and the shift amount between the two heater pads in the radial direction R or the circumferential direction I can be arbitrarily set.

(2) The arrangement pattern of the heater lines shown in FIGS. 3 and 5 is merely an example. FIG. 3 describes an example in which a pair of heater lines make approximately two rounds along the outer peripheral edge and four of them are arranged adjacent to each other in the radial direction R. However, the pair of heater lines have the same pattern on the outer peripheral edge. The arrangement pattern may be such that three or more laps are made along the line and six or more are adjacent to each other in the radial direction R.

(3) In the above embodiment, the case where the first heater line 41A and the second heater line 41B connected in parallel have substantially the same line width W1 and the lengths are substantially the same has been illustrated. Not limited. Even when the line width and length of the first heater line and the second heater line are changed and designed to have different resistance values, they should be arranged so as to be alternately adjacent to each other in the radial direction R. Therefore, the holding surface can be heated substantially uniformly.

(4) In the above embodiment, the electrostatic chuck 10 composed of the heater member 20 and the base member 90 and having a chuck electrode, a gas flow path, or the like formed in the heater member 20 has been exemplified, but is not limited thereto. For example, the gas flow path may not be provided in the heater member.

(5) In the above embodiment, the electrostatic chuck 10 is exemplified as the holding device, but the present invention is not limited to this. For example, this technique can be applied to a heater device such as a CVD (Chemical Vapor Deposition) heater, a vacuum chuck, and the like.

10: Electrostatic chuck (an example of holding device), 20, 120: Heater member, 30: Insulation plate, 30S1: Suction surface (corresponding to the first surface), 30S2: Joint surface (corresponding to the opposite surface), 40, 140: Heater electrode, 41, 141: Heater line, 41A, 141A: First heater line, 41B, 141B: Second heater line, 42, 142: Heater pad, 42A, 142A: First heater pad, 42B, 142B: 2nd heater pad, 50: Chuck electrode, 60, 69: Connection member, 61: Electrode side connection via, 62: Intermediate connection pad, 63: Terminal side via, 64: Terminal pad, 70: Bond material, 80: Heater feeding terminal, 80A: 1st heater feeding terminal (example of 1st feeding terminal), 80B: 2nd heater feeding terminal (example of 2nd feeding terminal), 89: chuck feeding terminal, 90: base member, 100: wafer (Example of object), C: Center, CL: Center line, R: Radial direction, I: Circumferential direction, IR: Inner peripheral region, OR: Outer peripheral region, RA: 1st radius, RB: 2nd radius, DA , DB: Distance, T: Thickness, W1: Line width, W2: Diameter

Claims (3)

A disk-shaped insulating plate having a first surface substantially orthogonal to the first direction,
The heater electrodes arranged on the insulating plate and
A first feeding terminal and a second feeding terminal provided on a surface of the insulating plate opposite to the first surface and connected to the heater electrode are provided, and an object is placed on the first surface. It is a holding device that holds
The insulating plate is divided into a plurality of regions including an outer peripheral region including the outer peripheral edge of the insulating plate and an inner peripheral region located radially inside the outer peripheral region when viewed from the first direction.
The heater electrode is
A first heater pad arranged in the outer peripheral region and connected to the first power feeding terminal via a connecting member, and a first heater pad.
A second heater pad arranged in the outer peripheral region and connected to the second power feeding terminal via a connecting member, and a second heater pad.
A pair of resistors having a smaller cross-sectional area than the first heater pad and the second heater pad, arranged in the outer peripheral region and each directly connected to the first heater pad and the second heater pad. Including heater line,
When the insulating plate is viewed from the first direction,
The first heater line and the second heater line constituting the pair of heater lines are arranged so as to be adjacent to each other in the radial direction from the center of the insulating plate toward the outer periphery.
A holding device in which the first heater pad and the second heater pad are arranged at different distances from the center of the insulating plate. The first heater pad and the second heater pad are arranged at positions shifted with respect to the circumferential direction along the outer peripheral edge of the insulating plate when the insulating plate is viewed from the first direction. The holding device described in. The first heater line and the second heater line are arranged so that at least three of the insulating plates are arranged so as to be alternately adjacent to each other in the radial direction when the insulating plate is viewed from the first direction. Item 2. The holding device according to item 2.

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