JP2017228649A - Holding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress ununiform temperature distribution of a wafer.SOLUTION: A holding device comprises a plate-like insulating plate having a first surface and a second surface on the side opposite to the first surface and formed of an insulating material, a heater arranged inside the insulating plate or on a second surface side of the insulating plate, and a plurality of power feeding terminals electrically connected to the heater. The holding device holds an object on a first surface side of the insulating plate. The heater includes a plurality of heater wires. The plurality of power feeding terminals include a first power feeding terminal electrically connected to at least one of the plurality of heater wires, and a second power feeding terminal electrically connected to more heater wires than the first power feeding terminal. A cross-sectional area orthogonal to a current flowing direction of the second power feeding terminal is larger than a cross-sectional area orthogonal to a current flowing direction of the first power feeding terminal.SELECTED DRAWING: Figure 2

Description

  The technology disclosed in this specification relates to a holding device that holds an object.

  For example, in a semiconductor manufacturing apparatus, an electrostatic chuck is used as a holding device that holds a wafer. The electrostatic chuck includes, for example, a plate-shaped ceramic plate and a chuck electrode provided inside the ceramic plate, and uses an electrostatic attractive force generated when a voltage is applied to the chuck electrode. The wafer is adsorbed and held on the surface of the ceramic plate (hereinafter referred to as “adsorption surface”).

  If the temperature distribution of the wafer held by the electrostatic chuck becomes uneven, the accuracy of each process (film formation, etching, exposure, etc.) on the wafer may be reduced. A uniform performance is required. Therefore, the electrostatic chuck is provided with a heater that is a conductive resistance heating element and a plurality of power supply terminals that are electrically connected to the heater. When power is supplied to a plurality of power supply terminals, the heater generates heat, and the temperature of the adsorption surface of the ceramic plate is controlled by heating with the generated heater.

  Further, an electrostatic chuck having a plurality of heater wires is known as a heater (see, for example, Patent Document 1). In this electrostatic chuck having a plurality of heater wires, a single-wire feed power supply terminal electrically connected to one heater wire and a multi-wire feed power supply terminal electrically connected to two heater wires are provided. ing.

JP, 2006-76646, A

  In the electrostatic chuck including the plurality of heater wires, a larger current flows as the number of electrically connected heater wires increases. That is, in the above-described conventional electrostatic chuck, a current larger than that of the single-wire connection power supply terminal flows through the plurality of power supply terminals. However, in the above-described conventional electrostatic chuck, the cross-sectional area perpendicular to the current flow direction of the single-wire connection power supply terminal and the cross-sectional area perpendicular to the current flow direction of the double-wire connection power supply terminal are the same. For this reason, the heat generation amount of the power supply terminal connected to the double line is larger than the heat generation amount of the power supply terminal connected to the single line. As a result, there is a possibility that the temperature distribution of the wafer becomes non-uniform due to variations in the temperature distribution of the adsorption surface of the ceramic plate.

  Such a problem is not limited to an electrostatic chuck that holds a wafer using electrostatic attraction, but is a problem common to a holding device that holds an object on the surface side of an insulating plate, such as a polyimide heater. .

  In this specification, the technique which can solve the subject mentioned above is disclosed.

  The technology disclosed in the present specification can be realized as, for example, the following forms.

(1) A holding device disclosed in the present specification has a first surface and a plate-like insulating plate formed of an insulating material and having a second surface opposite to the first surface. And a heater disposed inside the insulating plate or on the second surface side of the insulating plate, and a plurality of power supply terminals electrically connected to the heater, the first of the insulating plate In the holding device for holding an object on the surface side of the first, the heater includes a plurality of heater wires, and the plurality of power supply terminals are electrically connected to at least one of the plurality of heater wires. A cross-sectional area perpendicular to the current flow direction of the second power supply terminal, and a second power supply terminal that is electrically connected to a larger number of the heater wires than the first power supply terminal. Is larger than the cross-sectional area perpendicular to the current flow direction of the first power supply terminal. According to the holding device, the cross-sectional area perpendicular to the current flow direction of the second power supply terminal having a relatively large number of electrically connected heater wires (hereinafter referred to as “the number of connected heater wires”) is Since the number of heater wire connections is relatively small and the cross-sectional area perpendicular to the current flow direction of the first power supply terminal is larger, the difference in the amount of heat generated between the power supply terminals with different numbers of heater wire connections is suppressed. Therefore, it is possible to suppress the non-uniform temperature distribution of the wafer.

(2) In the holding device, all of the heater wires electrically connected to the first power supply terminal and the second power supply terminal are on a single virtual plane parallel to the first surface. It is good also as a structure characterized by being arrange | positioned. According to the present holding device, it is possible to prevent the temperature distribution of the wafer from becoming non-uniform, particularly by suppressing the difference in the amount of heat generated on the same plane of the insulating plate.

(3) In the holding device, the heater is disposed inside the insulating plate, and on the second surface side, a first terminal pad to which the first power feeding terminal is joined, and the second A second terminal pad to which the power supply terminal is joined, and one end of the second pad is electrically connected to each of the heater wires electrically connected to the first power supply terminal. And the other end of the first intermediate conductor directly connected to the first terminal pad and the other end of the heater wire electrically connected to the second power supply terminal. And a second intermediate conductor whose other end is directly connected to the second terminal pad, and the cross-sectional area perpendicular to the current flow direction of the second intermediate conductor is the first intermediate conductor It is good also as a structure larger than the cross-sectional area orthogonal to the electric current flow direction of an intermediate conductor.According to this holding device, the intermediate conductor electrically connected between the terminal pad connected to each heater wire and the power supply terminal is orthogonal to the direction of current flow as the number of heater wire connections increases. Large cross-sectional area. Thereby, it can suppress more reliably that the temperature distribution of a wafer becomes non-uniform | heterogenous by suppressing more effectively the difference in the emitted-heat amount between the electric power feeding terminals from which the number of connection of a heater wire differs. .

(4) In the holding device, the first power supply terminal and the second power supply terminal extend so as to protrude from the second surface side of the insulating plate to a side opposite to the first surface. The holding device further includes a base plate disposed on the second surface side of the insulating plate and having a coolant channel formed therein, and the base plate includes the first power supply terminal. A first housing space for housing at least a part of the first power receiving terminal and a second housing space for housing at least a part of the second power supply terminal. The cross-sectional area perpendicular to the direction in which the power supply terminal extends may be smaller than the cross-sectional area perpendicular to the direction in which the second power supply terminal extends in the second accommodation space. Since the coolant channel cannot be formed in the portion where the accommodation space of the base plate is formed, the cooling effect is reduced accordingly. On the other hand, according to this holding device, the cross-sectional area of the accommodation space is smaller as the accommodation space accommodates the power feeding terminal having a smaller cross-sectional area. Thereby, the reduction of the cooling effect of the base plate by the storage space can be suppressed by suppressing the formation range of the storage space of the base plate.

  The technology disclosed in the present specification can be realized in various forms, for example, in the form of a holding device, an electrostatic chuck, a heater, a vacuum chuck, a manufacturing method thereof, and the like. Is possible.

It is a perspective view showing roughly the appearance composition of electrostatic chuck 10 in an embodiment. It is explanatory drawing which shows roughly the cross-sectional structure (cross-sectional structure parallel to the Z-axis in the position of II-II) of the electrostatic chuck 10 in embodiment. It is explanatory drawing which shows roughly the cross-sectional structure (XY cross-section structure in the position of III-III) of the electrostatic chuck 10 in embodiment.

A. Embodiment:
A-1. Configuration of the electrostatic chuck 10:
FIG. 1 is a perspective view schematically showing an external configuration of an electrostatic chuck 10 in the present embodiment, and FIGS. 2 and 3 are explanatory views schematically showing a cross-sectional configuration of the electrostatic chuck 10 in the present embodiment. It is. In each figure, XYZ axes orthogonal to each other for specifying the direction are shown. In this specification, for convenience, the positive direction of the Z-axis is referred to as the upward direction, and the negative direction of the Z-axis is referred to as the downward direction. However, the electrostatic chuck 10 is actually installed in an orientation different from such an orientation. May be. 2 shows a cross-sectional configuration parallel to the Z-axis of the electrostatic chuck 10 at the position II-II in FIG. FIG. 3 shows an XY cross-sectional configuration of the electrostatic chuck 10 at the position of III-III in FIG.

  As shown in FIGS. 1 to 3, the electrostatic chuck 10 is an apparatus that holds an object (for example, a wafer W) by electrostatic attraction and holds the wafer W in a vacuum chamber of a semiconductor manufacturing apparatus, for example. Used to do. The electrostatic chuck 10 includes a ceramic plate 100 and a base plate 200 arranged side by side in a predetermined arrangement direction (in this embodiment, the vertical direction (Z-axis direction)). The ceramic plate 100 and the base plate 200 are such that the lower surface of the ceramic plate 100 (hereinafter referred to as “ceramic-side adhesive surface S2”) and the upper surface of the base plate 200 (hereinafter referred to as “base-side adhesive surface S3”) are arranged in the arrangement direction. It arrange | positions so that it may oppose. The electrostatic chuck 10 further includes an adhesive layer 300 disposed between the ceramic side adhesive surface S2 of the ceramic plate 100 and the base side adhesive surface S3 of the base plate 200. The ceramic plate 100 corresponds to the insulating plate in the claims, and the ceramic side adhesive surface S2 of the ceramic plate 100 corresponds to the second surface in the claims.

(Configuration of ceramic plate 100):
The ceramic plate 100 is, for example, a circular flat plate-like member, and is formed of ceramics. The diameter of the ceramic plate 100 is, for example, about 50 mm to 500 mm (usually about 200 mm to 350 mm), and the thickness of the ceramic plate 100 is, for example, about 1 mm to 10 mm.

Various ceramics can be used as a material for forming the ceramic plate 100. From the viewpoint of strength, wear resistance, plasma resistance, etc., for example, aluminum oxide (alumina, Al ₂ O ₃ ) or aluminum nitride (AlN) is used. It is preferable to use ceramics containing as a main component. In addition, the main component here means a component having the largest content ratio (weight ratio).

  As shown in FIG. 2, a pair of chuck electrodes 400 formed of a conductive material (for example, tungsten or molybdenum) is provided inside the ceramic plate 100. When a voltage is applied to the pair of chuck electrodes 400 from a power source (not shown), an electrostatic attractive force is generated, and the wafer W causes the upper surface of the ceramic plate 100 (hereinafter referred to as an “attracting surface S1”) by the electrostatic attractive force. It is fixed by adsorption. The adsorption surface S1 of the ceramic plate 100 corresponds to the first surface in the claims.

  As shown in FIGS. 2 and 3, a heater 500 made of a resistance heating element made of a conductive material (for example, tungsten or molybdenum) is provided inside the ceramic plate 100. When a voltage is applied to the heater 500 from a power source (not shown), the heater 500 generates heat to warm the ceramic plate 100, and the wafer W held on the suction surface S1 of the ceramic plate 100 is warmed. Thereby, the temperature control of the wafer W is realized. As shown in FIG. 3, the heater 500 is arranged substantially concentrically as viewed in the Z-axis direction in order to warm the adsorption surface S <b> 1 of the ceramic plate 100 as uniformly as possible. Detailed configurations of the heater 500 and a power feeding portion to the heater 500 will be described later.

(Configuration of base plate 200):
The base plate 200 is a circular flat plate-like member having the same diameter as the ceramic plate 100 or a larger diameter than the ceramic plate 100, and is formed of, for example, a metal (for example, aluminum or aluminum alloy). The diameter of the base plate 200 is, for example, about 220 mm to 550 mm (usually 220 mm to 350 mm), and the thickness of the base plate 200 is, for example, about 20 mm to 40 mm.

  A coolant channel 210 is formed inside the base plate 200. When a refrigerant (for example, a fluorine-based inert liquid or water) flows through the refrigerant flow path 210, the base plate 200 is cooled, and heat is transferred between the base plate 200 and the ceramic plate 100 via the adhesive layer 300. The ceramic plate 100 is cooled, and the wafer W held on the suction surface S1 of the ceramic plate 100 is cooled. Thereby, the temperature control of the wafer W is realized.

  The adhesive layer 300 includes an adhesive such as a silicone resin, an acrylic resin, or an epoxy resin, for example, and bonds the ceramic plate 100 and the base plate 200 together. The thickness of the adhesive layer 300 is, for example, about 0.1 mm to 1 mm.

A-2. Detailed configuration of heater 500:
As shown in FIG. 3, the heater 500 includes a first heater line 510, a second heater line 520, a third heater line 530, and a fourth heater line 540. The four heater wires 510 to 540 are arranged on a single virtual plane Q1 parallel to the suction surface S1 of the ceramic plate 100 (see FIG. 2). Also, the four heater wires 510 to 540 are arranged in different regions in the ceramic plate 100 as viewed in the Z-axis direction. Specifically, four fan-shaped regions partitioned by two virtual straight lines Q2 orthogonal to each other at the center position of the ceramic plate 100 as viewed in the Z direction are defined as a first region R1 to a fourth region R4. . The first heater wire 510 is disposed in the first region R1, the second heater wire 520 is disposed in the second region R2, the third heater 530 is disposed in the third region R3, and the fourth region A fourth heater wire 540 is arranged in the region R4.

  The first heater wire 510 includes a pair of end portions 511 and 512 that are electrically connected to different power supply terminals 62 and 64 (described later), and a heater that extends from one end portion 511 to the other end portion 512. Main body 513. One end 511 is disposed on the center side of the ceramic plate 100, and the other end 512 is disposed on the peripheral side of the ceramic plate 100. Hereinafter, one end 511 is referred to as an “inner end 511” and the other end 512 is referred to as an “outer end 512”.

  The heater body 513 includes first to fourth arc portions 514A to 514D and first to fourth straight portions 515A to 515D. The first to fourth arc portions 514A to 514D are centered on the center position of the ceramic plate 100 and extend along arcs having different diameters. The first linear portion 515A extends along the radial direction of the ceramic plate 100 from the inner end 511 to one end of the first arc portion 514A. The second linear portion 515B extends along the radial direction of the ceramic plate 100 from the other end of the first arc portion 514A to one end of the second arc portion 514B. The third straight portion 515C extends along the radial direction of the ceramic plate 100 from the other end of the second arc portion 514B to one end of the third arc portion 514C. The fourth linear portion 515D extends along the radial direction of the ceramic plate 100 from the other end of the third arc portion 514C to one end of the fourth arc portion 514D. The other end of the fourth arc portion 514 </ b> D is connected to the outer end portion 512.

  The second heater wire 520 includes an inner end 521 disposed on the center side of the ceramic plate 100, an outer end 522 disposed on the peripheral side of the ceramic plate 100, and from the inner end 521 to the outer end 522. And a heater main body 523 that extends. The third heater wire 530 includes an inner end 531 disposed on the center side of the ceramic plate 100, an outer end 532 disposed on the peripheral side of the ceramic plate 100, and from the inner end 531 to the outer end 532. And a heater body 533 that extends. The fourth heater wire 540 includes an inner end 541 disposed on the center side of the ceramic plate 100, an outer end 542 disposed on the peripheral side of the ceramic plate 100, and from the inner end 541 to the outer end 542. And a heater main body portion 543 that extends. The configurations of the heater main body portions 523 to 543 of the second to fourth heater wires 520 to 540 are the same as the configuration of the heater main body portion 513 of the first heater wire 510, and thus description thereof is omitted. In addition, the 1st-4th heater wires 510-540 shall be comprised with the resistance heating element with the same cross-sectional area orthogonal to the line direction of the said heater wire.

A-3. Detailed configuration of a power feeding portion to the heater 500:
As shown in FIG. 2, one inner driver electrode 516 and four outer driver electrodes 526 (only two are shown in FIG. 2) are provided inside the ceramic plate 100. The inner driver electrode 516 is disposed below the inner ends 511 to 541 of the four heater wires 510 to 540. The inner driver electrode 516 is formed of a conductive material (for example, tungsten or molybdenum), and is connected to inner end portions 511 to 541 of the four heater wires 510 to 540 through vias 514 that are columnar conductors. Electrically connected. Each outer driver electrode 526 is disposed below the outer ends 512 to 542 of the heater wires 510 to 540. The outer driver electrode 526 is made of a conductive material (for example, tungsten or molybdenum), and is electrically connected to the outer end portions 512 to 542 of the heater wires 510 to 540 through vias 524 that are columnar conductors. Connected.

  Further, one inner terminal pad 61 and four outer terminal pads 63 are provided on the ceramic side adhesive surface S2 side of the ceramic plate 100. The inner terminal pad 61 is disposed so as to be positioned below the inner driver electrode 516. The inner terminal pad 61 is a flat conductor (metallized layer), and the upper surface of the inner terminal pad 61 is electrically connected to the lower surface of the inner driver electrode 516 via a pad inner via 518 which is a columnar conductor. Connected. The inner terminal pad 61 is large enough to cover the four inner end portions 511 to 541 when viewed in the Z-axis direction. The pad inner via 518 is directly connected (bonded) to the upper surface of the inner terminal pad 61. The inner terminal pad 61 corresponds to the second terminal pad in the claims, and the inner via 518 for pads corresponds to the second intermediate conductor in the claims.

  Each outer terminal pad 63 is disposed so as to be located below the outer end portions 512 to 542 of the heater wires 510 to 540. Each outer terminal pad 63 is a flat conductor (metallized layer), and the upper surface of each outer terminal pad 63 is the lower surface of the outer driver electrode 526 via a pad outer via 528 that is a columnar conductor. Is electrically connected. Each outer terminal pad 63 is large enough to cover each outer end portion 512 to 542 when viewed in the Z-axis direction. Further, the outer via 528 for each pad is directly connected to the upper surface of each outer terminal pad 63. The outer terminal pad 63 corresponds to the first terminal pad in the claims, and the outer via 528 for pads corresponds to the first intermediate conductor in the claims.

  The cross-sectional area D5 orthogonal to the vertical direction (current flow direction) of the pad inner via 518 is larger than the cross-sectional area D6 orthogonal to the vertical direction of the pad outer via 528. The cross-sectional area D5 of the pad inner via 518 is preferably substantially the same as the value obtained by multiplying the cross-sectional area D6 of the pad outer via 528 by the heater number ratio. The heater number ratio is a numerical value (4) obtained by dividing the number of heater wires electrically connected to the inner via 518 (four) by the number of heater wires electrically connected to the outer via 528 (one). It is.

  As shown in FIG. 2, the electrostatic chuck 10 has one inner accommodation hole 22 and four outer accommodation holes 23. The inner accommodation hole 22 is a hole that extends through the adhesive layer 300 and the base plate 200 from the arrangement position of the inner terminal pad 61 so as to reach the lower surface S4 of the base plate 200 in the vertical direction. An inner power supply terminal 62 is accommodated in the inner accommodation hole 22. The inner power supply terminal 62 is a bar-like conductor extending in the vertical direction, and its upper end is directly connected to the lower surface of the inner terminal pad 61. The inner accommodation hole 22 corresponds to the second accommodation space in the claims, and the inner feeding terminal 62 corresponds to the second feeding terminal in the claims.

  Each outer accommodation hole 23 is a hole extending through the adhesive layer 300 and the base plate 200 from the arrangement position of each outer terminal pad 63 and extending in the vertical direction so as to reach the lower surface S4 of the base plate 200. An outer power supply terminal 64 is accommodated in each outer accommodation hole 23. The outer power supply terminal 64 is a bar-like conductor extending in the vertical direction, and its upper end is directly connected to the lower surface of the outer terminal pad 63. The outer housing hole 23 corresponds to the first housing space in the claims, and the outer power feeding terminal 64 corresponds to the first power feeding terminal in the claims.

  The opening area D4 orthogonal to the vertical direction of each outer housing hole 23 (the direction in which the outer power supply terminal 64 extends) is smaller than the opening area D3 orthogonal to the vertical direction of the inner housing hole 22 (the direction in which the inner power supply terminal 62 extends). The opening area D3 of the inner housing hole 22 is preferably substantially the same as a value obtained by multiplying the opening area D4 of one outer housing hole 23 by the above-described heater number ratio. Further, the cross-sectional area D1 orthogonal to the vertical direction (current flow direction) of the inner power supply terminal 62 is larger than the cross-sectional area D2 orthogonal to the vertical direction (current flow direction) of each outer terminal pad 63. Note that the cross-sectional area D1 of the inner power supply terminal 62 is preferably substantially the same as the value obtained by multiplying the cross-sectional area D2 of one outer power supply terminal 64 by the heater number ratio described above. In the present specification, the “cross-sectional area” is a section perpendicular to the current flow direction of the target member (the inner power supply terminal 62, the outer power supply terminal 64, the pad terminal pad 518, or the pad outer via 528). The area is preferably the area of the smallest part. Further, in this specification, the “opening area” refers to the area of the portion having the smallest opening area orthogonal to the extending direction of the inner feeding terminal 62 of the inner receiving hole 22 or the extending direction of the outer feeding terminal 64 of the outer receiving hole 23. It is preferable that the orthogonal opening area is the area of the smallest part.

A-4. Effects of this embodiment:
As described above, in the electrostatic chuck 10 of the present embodiment, the heater 500 includes a plurality of heater wires 510 to 540 that are arranged in different regions of the ceramic plate 100 and can be controlled in temperature independently of each other. It is configured. For this reason, the temperature distribution of the wafer held by the electrostatic chuck can be made more uniform and more accurate than when the heater is composed of only a single heater wire.

  Thus, when the number of heater wires increases, the number of components and the number of arrangement positions of the configuration for supplying power to the heater wires such as the power supply terminals increase accordingly. In contrast, in the electrostatic chuck 10 of the present embodiment, the inner end portions 511 to 541 of the four heater wires 510 to 540 are connected to the common inner driver electrode 516 and the pad inner via 518 via the via 514. The inner terminal pad 61 and the inner feeding terminal 62 are electrically connected. Thereby, the increase in the number of parts of the structure for supplying electric power to a heater wire and the number of arrangement positions can be controlled.

  The inner power supply terminal 62 is electrically connected to the four heater wires 510 to 540, while the outer power supply terminal 64 is electrically connected to one heater wire 510 (or 520 to 540). Yes. For this reason, when a voltage is applied from the power source to the inner feeding terminal 62 and the outer feeding terminal 64, a larger current flows in the inner feeding terminal 62 than in the outer feeding terminal 64. Here, if the inner power supply terminal 62 and the outer power supply terminal 64 have the same cross-sectional area perpendicular to the vertical direction, the heat generation amount of the inner power supply terminal 62 is larger than the heat generation amount of the outer power supply terminal 64. As a result, there is a possibility that the temperature distribution of the wafer W becomes non-uniform due to variations in the temperature distribution of the adsorption surface of the ceramic plate 100. On the other hand, in the electrostatic chuck 10 of the present embodiment, the cross-sectional area D1 orthogonal to the vertical direction of the inner power supply terminal 62 is larger than the cross-sectional area D2 orthogonal to the vertical direction of each outer power supply terminal 64. For this reason, the difference between the heat generation amount of the inner power supply terminal 62 and the heat generation amount of the outer power supply terminal 64 can be suppressed. That is, the temperature distribution of the wafer W is reduced by suppressing the difference in the amount of heat generated between the power supply terminals 62 and 64 having different numbers of electrically connected heater wires (hereinafter referred to as “the number of connected heater wires”). It is possible to suppress non-uniformity.

  Further, the cross-sectional area D5 perpendicular to the vertical direction of the pad inner via 518 is larger than the cross-sectional area D6 perpendicular to the vertical direction of the outer via 528 for pad. That is, the pad vias 518 and 528 electrically connected between the terminal pads 518 and 528 connected to the heater lines 510 to 540 and the power supply terminals 62 and 64 have a large number of heater lines connected. The cross-sectional area perpendicular to the current flow direction is larger. As a result, the temperature distribution of the wafer W is more reliably suppressed by more effectively suppressing the difference in the amount of heat generated between the power supply terminals 62 and 64 having different numbers of heater wire connections. can do.

  The four heater wires 510 to 540 are arranged on a single virtual plane Q1 parallel to the suction surface S1 of the ceramic plate 100 (see FIG. 2). For this reason, it can suppress that the temperature distribution of the wafer W becomes non-uniform | heterogenous especially by suppressing the difference in the emitted-heat amount on the same plane (layer) of the ceramic board 100. FIG.

  Further, since the refrigerant flow path 210 cannot be formed in the portion where the accommodation space of the base plate 200 is formed, the cooling effect is reduced accordingly. On the other hand, in the electrostatic chuck 10 of the present embodiment, the opening area D4 orthogonal to the vertical direction of each outer housing hole 23 (the direction in which the outer power feeding terminal 64 extends) is the vertical direction of the inner housing hole 22 (the inner power feeding). It is smaller than the opening area D3 orthogonal to the direction in which the terminal 62 extends. That is, the housing space that accommodates the power feeding terminal having a smaller cross-sectional area has a smaller cross-sectional area. Thereby, the reduction of the cooling effect of the base plate 200 by the storage space can be suppressed by suppressing the formation range of the storage space of the base plate 200.

B. Variations:
The technology disclosed in the present specification is not limited to the above-described embodiment, and can be modified into various forms without departing from the gist thereof. For example, the following modifications are possible.

  The configuration of the electrostatic chuck 10 in the above embodiment is merely an example, and can be variously modified. For example, in the above-described embodiment, a configuration for supplying power to the heater 500 (power supply terminals 62 and 64, terminal pads 61 and 63, pad inner vias 518 and 528, driver electrodes 516 and 526, vias 514 and 524, receiving holes) 22, 23, etc.) can be arbitrarily changed.

  In the above embodiment, the heater 500 is arranged inside the ceramic plate 100. However, the heater 500 is not inside the ceramic plate 100, but on the base plate 200 side of the ceramic plate 100 (the ceramic plate 100 and the adhesive layer). 300). In this case, the adhesive layer 300 adheres at least one of the ceramic plate 100 and the heater 500 and the base plate 200.

  In the above embodiment, the shape, position, number, etc. of the plurality of heater wires included in the heater 500 can be arbitrarily changed. For example, at least one of the four heater wires 510 to 540 may be arranged on a plane that is parallel to the suction surface S1 of the ceramic plate 100 and different from the virtual plane Q1. In this case, at least a part of the heater wires arranged on different planes may be overlapped when viewed in the Z-axis direction. The plurality of heater wires may have different cross-sectional areas perpendicular to the line direction of the heater wires.

  In the above-described embodiment, the cross-sectional area D5 orthogonal to the vertical direction of the inner via 518 for one pad is made larger than the cross-sectional area D6 orthogonal to the vertical direction of the outer via 528 for pads. However, the present invention is not limited to this, and the total cross-sectional area may be increased by increasing the number of vias so that the cross-sectional area D6 perpendicular to the vertical direction of the pad outer via 528 may be increased.

  In the above embodiment, the refrigerant flow path 210 is formed inside the base plate 200. However, the refrigerant flow path 210 is not inside the base plate 200, but the surface of the base plate 200 (for example, the base plate 200 and the like). It may be formed between the adhesive layer 300. In the above-described embodiment, a bipolar system in which a pair of chuck electrodes 400 is provided inside the ceramic plate 100 is employed. However, a monopolar system in which one chuck electrode 400 is provided inside the ceramic plate 100 is employed. It may be adopted.

  Moreover, the material which forms each member in the said embodiment is an illustration to the last, and each member may be formed with another material.

  The present invention is not limited to the electrostatic chuck 10 that holds the wafer W using electrostatic attraction, and includes other ceramic holding plates (for example, a ceramic plate and a base plate) that hold an object on the surface of the ceramic plate (for example, It can also be applied to a holding device (heater with shaft) that does not have a base plate or an adhesive layer and holds an object on the surface of a ceramic plate. Furthermore, the holding device includes, for example, a polyimide heater configured by sandwiching a heater wire of metal foil (copper foil or stainless steel foil) between polyimide resin layers. In this case, the polyimide heater itself corresponds to the insulating plate in the claims. In the present specification, “holding the object on the first surface side of the insulating plate” is not limited to holding the object directly on the first surface of the insulating plate. The object may be held on the surface side of 1 via another member. For example, the object may be held on the surface opposite to the polyimide heater of the ceramic plate separately disposed on the first surface of the polyimide heater.

  10: Electrostatic chuck 22: Inner accommodation hole 23: Outer accommodation hole 61: Inner terminal pad 62: Inner power supply terminal 63: Outer terminal pad 64: Outer power supply terminal 100: Ceramic plate 200: Base plate 210: Refrigerant flow path 300: Adhesive layer 400: chuck electrode 500: heater 510, 520, 530, 540: heater wire 511, 521, 531, 541: inner end 512, 522, 532, 542: outer end 513, 523, 533, 534: heater Main bodies 514, 524: Vias 514A to 514D: Arc portions 515A to 515D: Straight portions 516: Inner driver electrodes 518, 528: Pad terminal pads 526: Outer driver electrodes D1, D2, D5, D6: Cross-sectional area D3 D4: Opening area Q1: Single virtual plane Q2: Virtual straight Lines R1 to R4: Area S1: Adsorption surface S2: Ceramic side adhesion surface S3: Base side adhesion surface S4: Lower surface W: Wafer

Claims (4)

A plate-like insulating plate having a first surface and a second surface opposite to the first surface and formed of an insulating material; and the inside of the insulating plate or the insulating plate In a holding device that includes a heater disposed on the second surface side and a plurality of power supply terminals electrically connected to the heater, and holds an object on the first surface side of the insulating plate,
The heater includes a plurality of heater wires,
The plurality of power supply terminals are electrically connected to a first power supply terminal that is electrically connected to at least one of the plurality of heater wires, and more heater wires than the first power supply terminals. A second power supply terminal,
The holding device according to claim 1, wherein a cross-sectional area perpendicular to the current flow direction of the second power supply terminal is larger than a cross-sectional area perpendicular to the current flow direction of the first power supply terminal. The holding device according to claim 1, wherein
All the heater wires that are electrically connected to the first power supply terminal and the second power supply terminal are arranged on a single virtual plane parallel to the first surface. A holding device. The holding device according to claim 1 or 2,
The heater is disposed inside the insulating plate;
On the second surface side, a first terminal pad to which the first power supply terminal is bonded and a second terminal pad to which the second power supply terminal is bonded are arranged,
One end of the insulating plate is electrically connected to each heater wire electrically connected to the first power supply terminal, and the other end is directly connected to the first terminal pad. One intermediate conductor and one end electrically connected to each heater wire electrically connected to the second power supply terminal and the other end directly connected to the second terminal pad. An intermediate conductor, and
The holding device according to claim 1, wherein a cross-sectional area perpendicular to the current flow direction of the second intermediate conductor is larger than a cross-sectional area perpendicular to the current flow direction of the first intermediate conductor. In the holding device according to any one of claims 1 to 3,
The first power supply terminal and the second power supply terminal extend so as to protrude from the second surface side of the insulating plate to the side opposite to the first surface,
The holding device further includes:
A base plate disposed on the second surface side of the insulating plate and having a coolant channel formed therein;
The base plate is formed with a first housing space for housing at least part of the first power feeding terminal and a second housing space for housing at least part of the second power feeding terminal. ,
The cross-sectional area perpendicular to the direction in which the first power feeding terminal extends in the first housing space is smaller than the cross-sectional area perpendicular to the direction in which the second power feeding terminal extends in the second housing space. A holding device.

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