JP2018120910A - Retainer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain deterioration of uniformity of temperature distribution of a surface of a ceramics plate.SOLUTION: A retainer comprises: a ceramics plate having a first surface with an almost circular plane shape; a heater electrode arranged in each segment dividing the ceramics plate into plural pieces; and a pair of power feeding terminals. The heater electrode comprises a pair of heater pad parts constituting both ends of the heater electrode, and a heater line part connecting a pair of heater pad parts. Also, the retainer comprises: a first via for electrically connecting one heater pad part of each heater electrode to one of the pair of power feeding terminals; and a second via arranged at a position in line with the first via in a circumferential direction, and electrically connecting the other heater pad part of each heater electrode to the other of the pair of power feeding terminals. A cross section area of the heater pad part is larger than that of the heater line part. The heater line part includes plural folding portions positioned in a region between the pair of heater pad parts in the circumferential direction.SELECTED DRAWING: Figure 4

Description

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

  For example, an electrostatic chuck is used as a holding device for holding a wafer when manufacturing a semiconductor. The electrostatic chuck includes a ceramic plate and a chuck electrode provided inside the ceramic plate, and utilizes the electrostatic attraction generated when a voltage is applied to the chuck electrode. Hereinafter, the wafer is sucked and held on the “sucking surface”.

  If the temperature distribution of the wafer held on the electrostatic chuck becomes non-uniform, the accuracy of each process (film formation, etching, etc.) on the wafer may be reduced. Performance is required. Therefore, the electrostatic chuck is provided with a heater electrode composed of a resistance heating element (see, for example, Patent Document 1). The heater electrode includes a pair of heater pad portions constituting both ends of the heater electrode and a linear heater wire portion connecting the pair of heater pad portions. One heater pad portion of the pair of heater pad portions is electrically connected to one power supply terminal of the pair of power supply terminals via vias or the like, and the other heater pad portion of the pair of heater pad portions is And electrically connected to the other power supply terminal of the pair of power supply terminals via other vias or the like. When a voltage is applied from the power source to the heater electrode through the power supply terminal and vias, the ceramic electrode is heated by the heat generation of the heater electrode. The temperature control of the adsorption surface of the ceramic plate is performed by such heating by the heater electrode.

JP 2006-129183 A

  In order to accurately control the temperature of the adsorption surface of the ceramic plate, all or part of the ceramic plate is divided into a plurality of virtual areas (hereinafter referred to as “segments”), and heater electrodes are arranged in each segment. May be adopted. As the segment setting mode, for example, a mode is used in which all or part of the ceramic plate is divided into a plurality of segments arranged in the circumferential direction around the center point of the suction surface. According to such a configuration, by controlling the heater electrode arranged in each segment individually, the temperature control can be performed for each segment, and as a result, the temperature control of the adsorption surface of the ceramic plate is accurately performed. be able to.

  In the configuration described above, if the cross-sectional area of the pair of heater pads constituting both ends of the heater electrode is larger than the cross-sectional area of the heater wire, the amount of heat generated in the heater pad becomes smaller than the amount of heat generated in the heater wire. Therefore, in such a case, the temperature around the heater pad in each segment is lowered, the uniformity of the temperature distribution in the segment is lowered, and consequently the uniformity of the temperature distribution on the adsorption surface of the ceramic plate is lowered. There is a fear.

  Such a problem is not limited to the electrostatic chuck that holds the wafer using electrostatic attraction, but is a common problem for holding devices that include a ceramic plate and hold an object on the surface of the ceramic plate. .

   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 includes a ceramic plate having a substantially circular flat first surface, and a circle having at least a part of the ceramic plate centered on a center point of the first surface. A heater electrode which is a resistance heating element disposed in each of the segments divided into a plurality of segments arranged in the circumferential direction, and a pair of heater pad portions constituting both ends of the heater electrode, and the pair of heater pads A heater electrode provided with a linear heater wire portion connecting between the portions, a pair of power supply terminals, and each heater electrode provided with one heater pad portion and the pair of power supplies A first via that electrically connects one power supply terminal of the terminal and each of the heater electrodes, and is disposed at a position aligned with the first via in the circumferential direction; A second via that electrically connects the other heater pad portion of the tape pad portion and the other power supply terminal of the pair of power supply terminals, and holds an object on the first surface of the ceramic plate In the holding device, the cross-sectional area of the pair of heater pad portions is larger than the cross-sectional area of the heater wire portion, and the heater wire portion of the specific heater electrode that is at least one of the heater electrodes is in the circumferential direction. It includes a plurality of folded portions located in a region between the one heater pad portion and the other heater pad portion. According to this holding device, the heater wire portion of the specific heater electrode includes a plurality of folded portions located in a region between one heater pad portion and the other heater pad portion in the circumferential direction. A sufficient distance can be secured between the pad portion and the other heater pad portion, and a sufficient amount of heat is generated in the heater wire portion in the region between the one heater pad portion and the other heater pad portion. be able to. Therefore, according to the present holding device, it is possible to suppress the temperature of the region between one heater pad portion and the other heater pad portion in the segment where the specific heater electrode is disposed from being excessively low, As a result, it can suppress that the uniformity of the temperature distribution in a segment falls, and can suppress that the uniformity of the temperature distribution in the 1st surface of a ceramic board falls by extension.

(2) In the holding device, the heater wire portion of the specific heater electrode is a first circumferential portion substantially parallel to the circumferential direction, and the one heater pad portion in the circumferential direction. It is good also as a structure including the 1st circumferential part located in the area | region on the opposite side to said other heater pad part with respect to said one heater pad part. According to the present holding device, a sufficient distance can be secured between the one heater pad portion and the boundary line of the segment, so that the one heater pad portion is a heater of the other segment adjacent to the segment. It can suppress that it approaches a pad part too much, and can suppress the fall of the uniformity of the temperature distribution in the 1st surface of a ceramic board effectively.

(3) In the holding device, the heater wire portion of the specific heater electrode is a second circumferential portion substantially parallel to the circumferential direction, and the second heater pad portion in the circumferential direction. It is good also as a structure which contains the 2nd circumferential part located in the area | region on the opposite side to said one heater pad part with respect to said other heater pad part. According to the present holding device, a sufficient distance can be secured between the other heater pad portion and the boundary line of the segment, so that the other heater pad portion is a heater of another segment adjacent to the segment. It can suppress that it approaches a pad part too much, and can suppress further the fall of the uniformity of the temperature distribution in the 1st surface of a ceramic board more effectively.

(4) In the holding device, the heater wire portion of the specific heater electrode is a first via side portion connected to the one heater pad portion, and the one heater pad portion in the circumferential direction. A first via side portion including a plurality of circumferential portions substantially parallel to the circumferential direction, and a second via side portion connected to the other heater pad portion in a region that does not overlap with the circumferential direction, A second via side portion including a plurality of circumferential portions substantially parallel to the circumferential direction in a region that does not overlap with the other heater pad portion in the circumferential direction; the first via side portion; A first connecting portion connecting a plurality of folded portions, wherein the plurality of circumferential portions of the first via side portion and the plurality of circles of the second via side portion in the circumferential direction; In the region between the circumferential parts, it is almost straight in the circumferential direction. A first connection portion including a first linear portion, a second connection portion connecting the second via-side portion and the plurality of folded portions, wherein the first connection portion in the circumferential direction is the first connection portion. In a region between the plurality of circumferential portions of the via-side portion and the plurality of circumferential portions of the second via-side portion, a second linear portion that is substantially orthogonal to the circumferential direction And a second connection portion including a second linear portion adjacent to the first linear portion without passing through another portion of the heater line portion of the specific heater electrode. It is good also as a structure. According to the holding device, since the second linear portion is adjacent to the first linear portion without passing through the other portion of the heater wire portion of the heater electrode, the through hole formed in the ceramic plate is , Not a region between the first linear portion and the second linear portion, but a region closer to the first via side portion than the first linear portion, and second from the second linear portion. The possibility of being arranged in the region on the side of the via side portion can be increased. Here, when the through hole is disposed in a region between the first linear portion and the second linear portion, the through hole may interfere with the first linear portion and the second linear portion. Increases nature. In order to avoid interference between the through-hole and the first linear portion or the second linear portion, if the shape of the first linear portion or the second linear portion is changed, the changed first The linear portion or the second linear portion may interfere with other portions (a first via side portion, a second via side portion, etc.) constituting the heater line portion of the heater electrode. Therefore, in such a configuration, there is a possibility that the degree of freedom of arrangement of the through-holes and the like cannot be ensured while realizing the miniaturization of the pattern of the heater wire portion of the heater electrode in a certain size segment. On the other hand, when the through hole is arranged in a region closer to the first via side portion than the first linear portion or a region closer to the second via side portion than the second linear portion, the through hole Is likely to interfere with the first via side portion and the second via side portion. Avoiding interference between the through-hole and the first via-side part or the second via-side part shortens the length of the circumferential part constituting the first via-side part or the second via-side part. It can be realized relatively easily. Therefore, according to the present holding device, it is possible to easily ensure the degree of freedom of arrangement of the through holes and the like while realizing miniaturization of the pattern of the heater wire portion of the heater electrode.

  The technique disclosed in the present specification can be realized in various forms, for example, forms such as a holding device, an electrostatic chuck, a heater device such as a CVD heater, a vacuum chuck, and a manufacturing method thereof. Can be realized.

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 XZ cross-sectional structure of the electrostatic chuck 10 in embodiment. It is explanatory drawing which shows roughly the XY plane structure of the electrostatic chuck 10 in embodiment. It is explanatory drawing which shows XY cross-sectional structure of one heater electrode 500 arrange | positioned at one segment SE. It is explanatory drawing which shows roughly the structure of the heater electrode 500X in the electrostatic chuck 10 of a comparative example. It is explanatory drawing which shows the simulation result of the temperature distribution of the adsorption surface S1 of the ceramic board 100 of embodiment. It is explanatory drawing which shows the simulation result of the temperature distribution of the adsorption surface S1 of the ceramic board 100 of a comparative example. It is explanatory drawing which shows schematically the structure of the heater electrode 500a in a modification. It is explanatory drawing which shows roughly the structure of the heater electrode 500b in a modification.

A. Embodiment:
A-1. Configuration of the electrostatic chuck 10:
FIG. 1 is a perspective view schematically showing an external configuration of the electrostatic chuck 10 in the embodiment, and FIG. 2 is an explanatory diagram schematically showing an XZ sectional configuration of the electrostatic chuck 10 in the embodiment. 3 is an explanatory diagram schematically showing an XY plane configuration of the electrostatic chuck 10 according to the embodiment. 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 an XZ cross-sectional configuration of the electrostatic chuck 10 at the position II-II in FIG. 3, and FIG. 3 shows an XY plane configuration when the electrostatic chuck 10 is viewed from above. ing.

  The electrostatic chuck 10 is an apparatus that attracts and holds an object (for example, a wafer W) by electrostatic attraction, and is used, for example, to fix the wafer W in a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 10 includes a ceramic plate 100 and a base member 200 that are arranged in a predetermined arrangement direction (in this embodiment, the vertical direction (Z-axis direction)). The ceramic plate 100 and the base member 200 are disposed so that the lower surface S2 (see FIG. 2) of the ceramic plate 100 and the upper surface S3 of the base member 200 face each other in the arrangement direction.

  The ceramic plate 100 is a plate-like member having a substantially circular planar upper surface (hereinafter referred to as “adsorption surface”) S1 substantially orthogonal to the arrangement direction (Z-axis direction) described above, and ceramics (for example, alumina or aluminum nitride). Etc.). 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. The adsorption surface S1 of the ceramic plate 100 corresponds to the first surface in the claims. In the present specification, a direction perpendicular to the Z axis (that is, a direction parallel to the suction surface S1) is referred to as a “plane direction”. Further, as shown in FIG. 3, the circumferential direction around the center point P1 of the suction surface S1 in the surface direction is referred to as “circumferential direction CD”, and is orthogonal to the circumferential direction CD in the surface direction. The direction is referred to as “radial direction RD”.

  As shown in FIG. 2, a chuck electrode 400 formed of a conductive material (for example, tungsten or molybdenum) is provided inside the ceramic plate 100. The shape of the chuck electrode 400 when viewed in the Z-axis direction is, for example, a substantially circular shape. When a voltage is applied to the chuck electrode 400 from a power source (not shown), an electrostatic attractive force is generated, and the wafer W is attracted and fixed to the attracting surface S1 of the ceramic plate 100 by the electrostatic attractive force.

  In addition, as shown in FIG. 2, a plurality of heater electrodes 500 made of a resistance heating element formed of a conductive material (for example, tungsten or molybdenum) are provided inside the ceramic plate 100. When a voltage is applied to the heater electrode 500 from a power source (not shown), the heater electrode 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. The configuration of the heater electrode 500 and the configuration for supplying power to the heater electrode 500 will be described in detail later.

  The base member 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, metal (aluminum, aluminum alloy, or the like). The diameter of the base member 200 is, for example, about 220 mm to 550 mm (usually 220 mm to 350 mm), and the thickness of the base member 200 is, for example, about 20 mm to 40 mm.

  A coolant channel 210 is formed inside the base member 200. When a coolant (for example, a fluorine-based inert liquid or water) flows through the coolant channel 210, the base member 200 is cooled, and is transmitted between the base member 200 and the ceramic plate 100 via an adhesive layer 300 described later. The ceramic plate 100 is cooled by heat, 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 ceramic plate 100 and the base member 200 are joined to each other by an adhesive layer 300 disposed between the lower surface S2 of the ceramic plate 100 and the upper surface S3 of the base member 200. The adhesive layer 300 is made of an adhesive material such as a silicone resin, an acrylic resin, or an epoxy resin. The thickness of the adhesive layer 300 is, for example, about 0.1 mm to 1 mm.

A-2. Detailed configuration of the heater electrode 500 and the like:
Next, the configuration of the heater electrode 500 and the configuration for supplying power to the heater electrode 500 will be described in detail. As shown in FIG. 3, in the present embodiment, a plurality of virtual segments SE are set on the ceramic plate 100. More specifically, as viewed in the Z-axis direction, the ceramic plate 100 has a plurality of virtual annular regions (however, centered by a plurality of concentric first boundary lines BL1 around the center point P1 of the suction surface S1. Only the region including the point P1 is divided into circular regions), and each annular region is a plurality of virtual regions arranged in the circumferential direction CD by a plurality of second boundary lines BL2 extending in the radial direction RD. It is divided into SE. Thus, in the present embodiment, a part (each annular region) of the ceramic plate 100 is divided into a plurality of segments SE arranged in the circumferential direction CD centering on the center point P1 of the suction surface S1.

  One heater electrode 500 is disposed in each of the plurality of segments SE set on the ceramic plate 100 (see FIG. 4). The configuration of each heater electrode 500 will be described later.

  As shown in FIG. 2, the electrostatic chuck 10 has a configuration for supplying power to each heater electrode 500. Specifically, the electrostatic chuck 10 is formed with a pair of terminal holes 11 and 12 extending from the lower surface S <b> 4 of the base member 200 to the inside of the ceramic plate 100. Each of the terminal holes 11 and 12 includes a through hole 220 that penetrates the base member 200 in the vertical direction, a through hole 320 that penetrates the adhesive layer 300 in the vertical direction, and a recess 120 formed on the lower surface S2 side of the ceramic plate 100. Are integral holes configured by communicating with each other.

  A columnar first power supply terminal 21 is accommodated in the first terminal hole 11 which is one of the pair of terminal holes 11 and 12. In addition, a first electrode pad 31 is provided on the bottom surface of the concave portion 120 of the ceramic plate 100 constituting the first terminal hole 11. The first power supply terminal 21 is joined to the first electrode pad 31 by, for example, brazing. Further, the first electrode pad 31 is electrically connected to the first conductive region 51 in the driver electrode 50 through the first power supply side via 41. The first conductive region 51 of the driver electrode 50 is a pattern having a predetermined region parallel to the surface direction. Note that the first power supply terminal 21, the first electrode pad 31, the first power supply side via 41, and the first conductive region 51 are all formed of a conductive material (for example, tungsten or molybdenum). ing.

  Similarly, a columnar second power supply terminal 22 is accommodated in the second terminal hole 12 which is the other of the pair of terminal holes 11 and 12. A second electrode pad 32 is provided on the bottom surface of the concave portion 120 of the ceramic plate 100 constituting the second terminal hole 12. The second power supply terminal 22 is joined to the second electrode pad 32 by, for example, brazing. The second electrode pad 32 is electrically connected to the second conductive region 52 in the driver electrode 50 through the second power supply side via 42. The second conductive region 52 of the driver electrode 50 is a pattern having a predetermined region parallel to the surface direction. Note that the second power supply terminal 22, the second electrode pad 32, the second power supply side via 42, and the second conductive region 52 are all formed of a conductive material (for example, tungsten or molybdenum). ing.

  Each heater electrode 500 arranged in each segment SE is connected in parallel to the pair of conductive regions (first conductive region 51 and second conductive region 52) in the driver electrode 50 described above. Specifically, one end (first heater pad portion 501 described later) of each heater electrode 500 is connected via a first heater-side via 61 formed of a conductive material (for example, tungsten or molybdenum). The other end of each heater electrode 500 (second heater pad portion 502 described later) is electrically connected to the first conductive region 51 via a second heater side via 62 formed of a conductive material. The second conductive region 52 is electrically connected.

  The pair of power supply terminals (the first power supply terminal 21 and the second power supply terminal 22) are connected to a power source (not shown). The voltage from the power supply includes a pair of power supply terminals (first power supply terminal 21 and second power supply terminal 22), a pair of electrode pads (first electrode pad 31 and second electrode pad 32), and a pair of power supply terminals. The power supply side vias (first power supply side via 41 and second power supply side via 42) are supplied to the pair of conductive regions (first conductive region 51 and second conductive region 52) of the driver electrode 50, Further, the voltage is applied to the heater electrode 500 via a pair of heater side vias (first heater side via 61 and second heater side via 62) provided for each heater electrode 500. Thereby, each heater electrode 500 generates heat.

  In the configuration for supplying power to each heater electrode 500 described above, the first heater-side via 61 is provided for each heater electrode 500, and one end of the heater electrode 500 (first heater pad portion 501 described later). And the first power supply terminal 21 which is one of the pair of power supply terminals (the first power supply terminal 21 and the second power supply terminal 22) (the first conductive region 51 of the driver electrode 50, the first power supply). It is electrically connected (via the side via 41 and the first electrode pad 31), and corresponds to the first via in the claims. The second heater side via 62 is provided for each heater electrode 500, and the other end of the heater electrode 500 (second heater pad portion 502 to be described later) and a pair of power supply terminals (first power supply terminal 21 and The second power supply terminal 22, which is the other of the second power supply terminals 22) (via the second conductive region 52 of the driver electrode 50, the second power supply side via 42, and the second electrode pad 32). It is electrically connected and corresponds to the second via in the claims.

  Next, the configuration of each heater electrode 500 will be described in detail. FIG. 4 is an explanatory diagram showing an XY cross-sectional configuration of one heater electrode 500 arranged in one segment SE (see FIG. 3). In the present embodiment, since the heater electrode 500 having the same configuration is arranged in each segment SE, the configuration of one heater electrode 500 will be described as a representative. The heater electrode 500 described below corresponds to a specific heater electrode in the claims.

  As shown in FIG. 4, the heater electrode 500 includes a pair of heater pad portions 501 and 502 constituting both ends of the heater electrode 500 and a linear heater wire portion 504 connecting the pair of heater pad portions 501 and 502. Is provided.

  The first heater pad portion 501, which is one of the pair of heater pad portions 501 and 502, is disposed at a position overlapping the first heater side via 61 as viewed in the Z-axis direction, and is connected to the first heater side via 61. It is connected. The cross-sectional area of the first heater pad portion 501 as viewed in the Z-axis direction (that is, radius × radius × π when the cross section in the plane direction is circular) is the Z-axis direction of the first heater-side via 61. It is larger than the cross-sectional area in view (ie, when the cross section in the plane direction is circular, radius × radius × π). Similarly, the second heater pad portion 502, which is the other of the pair of heater pad portions 501, 502, is disposed at a position overlapping the second heater side via 62 as viewed in the Z-axis direction, and the second heater side It is connected to the via 62. The cross-sectional area of the second heater pad portion 502 as viewed in the Z-axis direction (that is, radius × radius × π when the cross section in the plane direction is circular) is the Z-axis direction of the second heater-side via 62. It is larger than the cross-sectional area in view (ie, when the cross section in the plane direction is circular, radius × radius × π).

  As shown in FIG. 4, a pair of heater side vias (first heater side via 61 and second heater side via 62) provided for each heater electrode 500 are arranged so as to be aligned with each other in the circumferential direction CD. ing. Therefore, the pair of heater pad portions (the first heater pad portion 501 and the second heater pad portion 502) constituting both ends of each heater electrode 500 are also arranged so as to be aligned with each other in the circumferential direction CD. In the following description, a region aligned (overlapping) with the first heater pad portion 501 (or the second heater pad portion 502) in the circumferential direction CD is referred to as a “pad overlapping region R1”, and in the circumferential direction CD. A region that does not line up (does not overlap) the first heater pad portion 501 (or the second heater pad portion 502) is referred to as a “pad non-overlapping region R2.”

  The heater wire portion 504 is a linear pattern extending so that one stroke can be drawn from a connection location with the first heater pad portion 501 to a connection location with the second heater pad portion 502. The cross-sectional area of the heater wire portion 504 when viewed in the plane direction (that is, (width in the direction perpendicular to the extending direction in the plane direction) × (thickness in the Z-axis direction)) was viewed in the plane direction. The cross-sectional area of the first heater pad portion 501 (ie, (width in the surface direction) × (thickness in the Z-axis direction)) and the cross-sectional area of the second heater pad portion 502 (ie, (in the surface direction) Smaller than (width) × (thickness in the Z-axis direction)).

  The heater wire portion 504 is composed of a plurality of portions surrounded by a one-dot chain line in FIG. Specifically, the heater wire portion 504 includes a first via-side portion 510, a second via-side portion 520, a first connection portion 530, a second connection portion 540, and a plurality of (five ) And a folded portion 550.

  The first via side portion 510 constituting the heater wire portion 504 is a portion connected to the first heater pad portion 501. The first via-side portion 510 mainly connects between a plurality of circumferential portions 511 substantially parallel to the circumferential direction CD and the ends of two circumferential portions 511 adjacent to each other in the radial direction RD. It is comprised from the linear part 512 extended substantially parallel to radial direction RD. When attention is paid to one circumferential portion 511, one end portion of the circumferential portion 511 is connected to another circumferential portion 511 adjacent to one side in the radial direction RD by a linear portion 512. The other end of the circumferential portion 511 is connected to another circumferential portion 511 adjacent to the other side in the radial direction RD by another linear portion 512.

  In the present embodiment, the plurality of circumferential portions 511 constituting the first via-side portion 510 are arranged in the pad non-overlapping region R2, and the first heater pad portion 501 in the pad overlapping region R1. On the other hand, it is also arranged in the region opposite to the second heater pad portion 502. Hereinafter, a circumferential portion 511 disposed in a region opposite to the second heater pad portion 502 with respect to the first heater pad portion 501 in the pad overlapping region R1 is defined as a first specific circumferential shape. This is referred to as a part 513. In the present embodiment, the first via-side portion 510 includes two first specific circumferential portions 513. The first specific circumferential portion 513 corresponds to the first circumferential portion in the claims.

  Similarly, the second via side portion 520 constituting the heater line portion 504 is a portion connected to the second heater pad portion 502. The second via-side portion 520 mainly connects between the plurality of circumferential portions 521 substantially parallel to the circumferential direction CD and the ends of the two circumferential portions 521 adjacent to each other in the radial direction RD. It is comprised from the linear part 522 extended substantially parallel to radial direction RD. When attention is paid to one circumferential portion 521, one end portion of the circumferential portion 521 is connected to another circumferential portion 521 adjacent to one side in the radial direction RD by a linear portion 522. The other end portion of the circumferential portion 521 is connected to another circumferential portion 521 adjacent to the other side in the radial direction RD by another linear portion 522.

  In the present embodiment, the plurality of circumferential portions 521 constituting the second via-side portion 520 are arranged in the pad non-overlapping region R2, and the second heater pad portion 502 in the pad overlapping region R1. On the other hand, it is also arranged in a region opposite to the first heater pad portion 501. Hereinafter, a circumferential portion 521 disposed in a region opposite to the first heater pad portion 501 with respect to the second heater pad portion 502 in the pad overlapping region R1 is a second specific circumferential shape. This is referred to as a portion 523. In the present embodiment, the second via-side portion 520 includes two second specific circumferential portions 523. The second specific circumferential portion 523 corresponds to the second circumferential portion in the claims.

  The plurality of folded portions 550 constituting the heater wire portion 504 are located in a region between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD. In the circumferential direction CD, the region between the first heater pad portion 501 and the second heater pad portion 502 is the first heater pad portion 501 and the second heater pad portion 501 in the above-described pad overlapping region R1. This is an area sandwiched between the heater pads 502. Further, when the folded portion 550 is located in the region between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD, at least a part of the folded portion 550 is in the circumferential direction CD. In FIG. 4, it is located in a region between the first heater pad portion 501 and the second heater pad portion 502. Further, in this specification, the “folded portion” refers to one end (for example, a connection position with the first heater pad portion 501) of the heater wire portion 504 along the extending direction of the heater wire portion 504 and the other end (for example, the first portion). 2 extending from the one side to the other side on a predetermined virtual straight line (for example, the virtual straight line VL shown in FIG. 4) on the path toward the heater pad portion 502 of the second heater pad portion 502, and the virtual straight line VL A linear portion including one combination of a portion extending from the other side so as to cross the one side. In the present embodiment, each folded portion 550 includes a portion extending so as to cross the virtual straight line VL substantially parallel to the circumferential direction CD from the outer peripheral side of the radial direction RD toward the center point P1, and the virtual straight line VL in the radial direction RD. And a portion extending so as to cross from the center point P1 side to the outer peripheral side.

  The first connection portion 530 constituting the heater wire portion 504 includes an end portion of the first via side portion 510 opposite to the connection portion with the first heater pad portion 501, and a group of the plurality of folded portions 550. It is a part which connects one edge part of these. The first connection portion 530 includes a first linear portion 531. The first linear portion 531 is a linear portion that is substantially parallel to the radial direction RD (that is, substantially orthogonal to the circumferential direction CD), and the first via side portion 510 in the circumferential direction CD. A plurality of circumferential portions 511 (in the pad non-overlapping region R2) and a plurality of circumferential portions 521 in the second via-side portion 520 (in the pad non-overlapping region R2). It is a part located in the area between.

  Similarly, the second connection portion 540 constituting the heater wire portion 504 includes an end portion of the second via-side portion 520 opposite to the connection portion with the second heater pad portion 502, and a plurality of folded portions. It is a part which connects the other edge part of 550 group. The second connection portion 540 includes a second straight portion 542. The second linear portion 542 is a linear portion that is substantially parallel to the radial direction RD (that is, substantially orthogonal to the circumferential direction CD), and the first via side portion 510 in the circumferential direction CD. A plurality of circumferential portions 511 (in the pad non-overlapping region R2) and a plurality of circumferential portions 521 in the second via-side portion 520 (in the pad non-overlapping region R2). It is a part located in the area between. As shown in FIG. 4, the second linear portion 542 is adjacent to the first linear portion 531 of the first connection portion 530 without passing through other portions of the heater wire portion 504 of the heater electrode 500. ing.

A-3. Effects of this embodiment:
As described above, the electrostatic chuck 10 according to the present embodiment includes the ceramic plate 100 having the substantially circular planar suction surface S1 substantially orthogonal to the Z-axis direction, and at least a part of the ceramic plate 100 on the suction surface S1. A heater electrode 500 that is a resistance heating element disposed in each segment SE when divided into a plurality of segments SE arranged in the circumferential direction CD centered on the center point P1, and a pair of power supply terminals (first power supply terminals) 21 and a second power supply terminal 22). The heater electrode 500 includes a pair of heater pad portions 501 and 502 constituting both ends of the heater electrode 500, and a linear heater wire portion 504 connecting the pair of heater pad portions 501 and 502. The electrostatic chuck 10 of the present embodiment is further provided for each heater electrode 500, and includes a first heater pad portion 501 constituting one end of the heater electrode 500 and one power supply terminal (first power supply terminal 21). A first heater-side via 61 to be electrically connected and each heater electrode 500 are provided and arranged at a position aligned with the first heater-side via 61 in the circumferential direction CD to constitute the other end of the heater electrode 500. A second heater-side via 62 that electrically connects the second heater pad portion 502 and the other power supply terminal (second power supply terminal 22) is provided. Further, the cross-sectional area of the pair of heater pad portions 501 and 502 is larger than the cross-sectional area of the heater wire portion 504. Further, the heater wire portion 504 of each heater electrode 500 includes a plurality of folded portions 550 that are located in a region between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD.

  Since the electrostatic chuck 10 of the present embodiment has the above-described configuration, as described below, it is possible to suppress a decrease in the uniformity of the temperature distribution on the attracting surface S1.

  FIG. 5 is an explanatory diagram schematically showing the configuration of the heater electrode 500X in the electrostatic chuck 10 of the comparative example. The heater electrode 500X in the electrostatic chuck 10 of the comparative example shown in FIG. 5 has only one folded portion 550 in a region between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD. The existing point is different from the heater electrode 500 (FIG. 4) of the embodiment in which a plurality of folded portions 550 exist in the same region. In the heater electrode 500X of the comparative example, the first connection portion 530 includes only the first linear portion 531 and the first linear portion 531 is a straight line continuous with a part of the folded portion 550. Is formed. Similarly, the second connecting portion 540 is composed of only the second linear portion 542, and the second linear portion 542 constitutes a linear portion continuous with the other portion of the folded portion 550. ing.

  As described above, in the heater electrode 500X in the electrostatic chuck 10 of the comparative example, one folded portion 550 is provided in the region between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD. Only exists. Therefore, in the electrostatic chuck 10 of the comparative example, the distance between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD is shortened, and the first heater pad portion 501 and the first heater pad portion 501 The amount of heat generated by the heater wire portion 504 in the region between the two heater pad portions 502 is reduced. Here, as described above, since the cross-sectional areas of the first heater pad portion 501 and the second heater pad portion 502 are larger than the cross-sectional area of the heater wire portion 504, the first heater pad portion 501 and the second heater pad portion 504 The heat generation amount in the second heater pad portion 502 is smaller than the heat generation amount in the heater wire portion 504. Therefore, the temperature of the region immediately above the first heater pad portion 501 and the second heater pad portion 502 on the suction surface S1 tends to be low. In the electrostatic chuck 10 of the comparative example, since the distance between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD is short, the regions where the temperature on the suction surface S1 tends to be low are mutually connected. It will be close. Further, in the electrostatic chuck 10 of the comparative example, since the amount of heat generated by the heater wire portion 504 in the region between the first heater pad portion 501 and the second heater pad portion 502 is small, the temperature on the suction surface S1 is low. It is not possible to secure a sufficient amount of heat generation in the vicinity of the region where it tends to occur. Therefore, in the electrostatic chuck 10 of the comparative example, the temperature distribution in the segment SE is caused by excessively lowering the temperature of the region between the first heater pad portion 501 and the second heater pad portion 502 in each segment SE. There is a possibility that the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 100 may be lowered.

  On the other hand, as shown in FIG. 4, in the heater electrode 500 in the electrostatic chuck 10 of the present embodiment, a region between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD. There are a plurality of folded portions 550. Therefore, in the electrostatic chuck 10 of the present embodiment, a sufficient distance can be secured between the first heater pad portion 501 and the second heater pad portion 502, and the first heater pad portion 501 and the first heater pad portion 501 The amount of heat generated by the heater wire portion 504 in the region between the two heater pad portions 502 can be sufficiently secured. Therefore, in the electrostatic chuck 10 of the present embodiment, it is possible to suppress the temperature of the region between the first heater pad portion 501 and the second heater pad portion 502 in each segment SE from becoming excessively low. As a result, it is possible to suppress a decrease in the uniformity of the temperature distribution in the segment SE, and consequently, it is possible to suppress a decrease in the uniformity of the temperature distribution on the adsorption surface S1 of the ceramic plate 100.

  6 and 7 are explanatory diagrams illustrating simulation results of the temperature distribution of the adsorption surface S1 of the ceramic plate 100. FIG. FIG. 6 shows an example of a simulation result of the temperature distribution on the adsorption surface S1 when power is supplied to the heater electrode 500 of the present embodiment arranged in one segment SE in the ceramic plate 100. FIG. Similarly, an example of a simulation result of the temperature distribution of the adsorption surface S1 when power is supplied to the heater electrode 500X of the comparative example arranged in one segment SE is shown.

  As shown in FIG. 7, when the heater electrode 500X of the comparative example is used, the maximum temperature Tmax is 132.8 ° C., the minimum temperature Tmin is 127.6 ° C., and the maximum temperature difference ΔT is 5.2 ° C. there were. The minimum temperature Tmin was recorded in the vicinity of an intermediate point between the first heater pad portion 501 and the second heater pad portion 502.

  On the other hand, as shown in FIG. 6, when the heater electrode 500 of this embodiment is used, the maximum temperature Tmax is 132.9 ° C., the minimum temperature Tmin is 128.6 ° C., and the maximum temperature difference ΔT is 4. It was 3 ° C. The minimum temperature Tmin was recorded at a position immediately above the first heater pad portion 501 and the second heater pad portion 502. As described above, when the heater electrode 500 of the present embodiment is used, the maximum temperature difference ΔT can be reduced as compared with the case of using the heater electrode 500X of the comparative example, that is, the adsorption surface S1. It was confirmed that a decrease in uniformity of temperature distribution can be suppressed.

  Further, the heater electrode 500 in the electrostatic chuck 10 of the present embodiment includes a first specific circumferential portion 513 that is substantially parallel to the circumferential direction CD. The first specific circumferential portion 513 is aligned with the first heater pad portion 501 in the circumferential direction CD, and is opposite to the second heater pad portion 502 with respect to the first heater pad portion 501. Located in the area. Therefore, in the electrostatic chuck 10 of the present embodiment, the first heater pad 501 and the second boundary line BL2 of the segment SE (for example, the second boundary line BL2 that defines the left end of the segment SE shown in FIG. 4). A sufficient distance can be taken between the two. As a result, the first heater pad portion 501 has a heater pad portion of another segment SE adjacent to the segment SE (for example, another segment SE (not shown) located on the left side of the segment SE shown in FIG. 4). It is possible to prevent the second heater pad portion 502) from being too close. If the distance between the first heater pad part 501 and the heater pad part of the other segment SE is short, the regions where the temperature on the suction surface S1 tends to be low are close to each other, and thus the temperature distribution on the suction surface S1. The uniformity of the is easy to decrease. In the electrostatic chuck 10 of the present embodiment, the first heater pad portion 501 can be prevented from coming too close to the heater pad portions of the other segments SE, so the uniformity of the temperature distribution on the suction surface S1 can be reduced. It can be effectively suppressed. In the electrostatic chuck 10 of the present embodiment, since the heater wire portion 504 of the heater electrode 500 includes a plurality of (two) first specific circumferential portions 513, the first heater pad portion 501 and A sufficient amount of heat can be generated in the heater wire portion 504 of the heater electrode 500 in the region between the heater pads of the other segments SE, and the temperature distribution on the suction surface S1 can be more effectively reduced. Can be suppressed.

  In addition, the heater electrode 500 in the electrostatic chuck 10 of the present embodiment further includes a second specific circumferential portion 523 that is substantially parallel to the circumferential direction CD. The second specific circumferential portion 523 is aligned with the second heater pad portion 502 in the circumferential direction CD, and is opposite to the first heater pad portion 501 with respect to the second heater pad portion 502. Located in the area. Therefore, in the electrostatic chuck 10 according to the present embodiment, the second boundary line BL2 between the second heater pad portion 502 and the segment SE (for example, the second boundary line BL2 defining the right end of the segment SE shown in FIG. 4). A sufficient distance can be taken between the two. As a result, the second heater pad portion 502 has a heater pad portion of another segment SE adjacent to the segment SE (for example, another segment SE (not shown) located on the right side of the segment SE shown in FIG. 4). The first heater pad portion 501) can be prevented from being too close. When the distance between the second heater pad portion 502 and the heater pad portion of the other segment SE is short, regions where the temperature on the suction surface S1 tends to be low are close to each other, and thus the temperature distribution on the suction surface S1. The uniformity of the is easy to decrease. In the electrostatic chuck 10 of the present embodiment, the second heater pad portion 502 can be prevented from coming too close to the heater pad portions of the other segments SE, so that the uniformity of the temperature distribution on the suction surface S1 is reduced. Can be suppressed. In the electrostatic chuck 10 of the present embodiment, since the heater wire portion 504 of the heater electrode 500 includes a plurality of (two) second specific circumferential portions 523, the second heater pad portion 502 and A sufficient amount of heat can be generated in the heater wire portion 504 of the heater electrode 500 in the region between the heater pads of the other segments SE, and the temperature distribution on the suction surface S1 can be more effectively reduced. Can be suppressed.

  From the viewpoint of both the point that suppresses the decrease in uniformity of temperature distribution by focusing on one segment SE and the point that suppresses the decrease in uniformity of temperature distribution across two adjacent segments SE. One heater pad portion 501 is located at a position close to the boundary between the first region and the second region when the segment SE is divided into four virtual regions from the first region to the fourth region along the circumferential direction CD. It is preferable that the second heater pad portion 502 is disposed at a position close to the boundary between the third region and the fourth region.

  In addition, the heater wire portion 504 of the heater electrode 500 in the electrostatic chuck 10 of this embodiment is connected to the first via-side portion 510 connected to the first heater pad portion 501 and the second heater pad portion 502. Second via-side portion 520 formed. The first via-side portion 510 has a plurality of circumferential portions 511 substantially parallel to the circumferential direction CD in a region (pad non-overlapping region R2) that does not overlap the first heater pad portion 501 in the circumferential direction CD. Including. Similarly, the second via-side portion 520 has a plurality of circumferential shapes substantially parallel to the circumferential direction CD in a region (pad non-overlapping region R2) that does not overlap the second heater pad portion 502 in the circumferential direction CD. A portion 521 is included. The heater wire portion 504 of the heater electrode 500 further includes a first connection portion 530 that connects the first via side portion 510 and the plurality of folded portions 550, a second via side portion 520, and the plurality of folded portions 550. And a second connection portion 540 that connects the two. The first connection portion 530 includes the plurality of circumferential portions 511 (which are located in the pad non-overlapping region R2) included in the first via side portion 510 and the second via side in the circumferential direction CD. A region between the plurality of circumferential portions 521 included in the portion 520 (however, located in the pad non-overlapping region R2) is substantially orthogonal to the circumferential direction CD (that is, substantially parallel to the radial direction RD). A first linear portion 531. The second connection portion 540 includes a plurality of circumferential portions 511 (which are located in the pad non-overlapping region R2) included in the first via side portion 510 in the circumferential direction CD and the second connection portion 540. A region between the plurality of circumferential portions 521 included in the via-side portion 520 (however, located in the pad non-overlapping region R2) is substantially orthogonal to the circumferential direction CD (that is, in the radial direction RD). A second linear portion 542 (substantially parallel). The second linear portion 542 is adjacent to the first linear portion 531 without passing through other portions of the heater wire portion 504 of the heater electrode 500.

  Here, another portion of the heater wire portion 504 of the heater electrode 500 (for example, another linear portion substantially parallel to the radial direction RD) between the first linear portion 531 and the second linear portion 542. In the configuration in which the through hole (for example, the pin insertion hole or the gas supply hole) formed in the ceramic plate 100 is a region between the first linear portion 531 and the second linear portion 542. There is a high possibility of being placed in. As a result, the possibility that the through hole interferes with the first linear portion 531 and the second linear portion 542 is increased. If the shape of the first linear portion 531 or the second linear portion 542 is changed in order to avoid interference between the through hole and the first linear portion 531 or the second linear portion 542, the change is made. The subsequent first linear portion 531 or the second linear portion 542 is another portion constituting the heater wire portion 504 of the heater electrode 500 (the first via side portion 510, the second via side portion 520, etc.). There is a risk of interference. Therefore, in such a configuration, there is a possibility that the degree of freedom of arrangement of the through-holes and the like cannot be ensured while realizing the miniaturization of the pattern of the heater wire portion 504 of the heater electrode 500 in a certain segment SE. .

  On the other hand, in the electrostatic chuck 10 of the present embodiment, the second linear portion 542 is adjacent to the first linear portion 531 without passing through other portions of the heater wire portion 504 of the heater electrode 500. Therefore, the through-hole formed in the ceramic plate 100 has a region closer to the first via side portion 510 than the first linear portion 531 and closer to the second via side portion 520 than the second linear portion 542. The possibility of being placed in the area increases. When the through hole is arranged in a region closer to the first via side portion 510 than the first linear portion 531 and a region closer to the second via side portion 520 than the second linear portion 542, the through hole Is likely to interfere with the first via side portion 510 and the second via side portion 520. Avoiding interference between the through-hole and the first via-side portion 510 or the second via-side portion 520 means that the circumferential portion 511 constituting the first via-side portion 510 or the second via-side portion 520 is used. It can be realized relatively easily by shortening the length of 521 or the like. Therefore, in the electrostatic chuck 10 of the present embodiment, the degree of freedom of arrangement of the through holes and the like can be ensured while realizing the miniaturization of the pattern of the heater wire portion 504 of the heater electrode 500.

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 embodiment, the folding direction of each folded portion 550 constituting the heater wire portion 504 of the heater electrode 500 can be arbitrarily changed. FIG. 8 is an explanatory diagram schematically showing the configuration of the heater electrode 500a in a modified example. In the heater electrode 500a of the modified example shown in FIG. 8, similarly to the heater electrode 500 (FIG. 4) of the above embodiment, between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD. There are a plurality of (eight) folded portions 550 in the region. However, in the above embodiment, each folded portion 550 includes a portion extending so as to cross the virtual straight line VL substantially parallel to the circumferential direction CD from the outer peripheral side of the radial direction RD to the center point P1 side, and the virtual straight line VL having a diameter The heater electrode 500a according to the modification shown in FIG. 8 is configured to include one combination of a portion extending so as to cross from the center point P1 side in the direction RD to the outer peripheral side. However, a portion extending so as to cross the virtual straight line VL substantially parallel to the radial direction RD from one side of the circumferential direction CD to the other side, and so as to cross the virtual straight line VL from the other side of the circumferential direction CD to the one side. It is comprised so that one combination of the extended part may be included. Also in the heater electrode 500a of the modified example having such a configuration, a region between the first heater pad portion 501 and the second heater pad portion 502 in the circumferential direction CD, similarly to the heater electrode 500 of the above embodiment. Since there are a plurality of folded portions 550, a sufficient distance can be secured between the first heater pad portion 501 and the second heater pad portion 502, and the first heater pad portion 501 and the second heater pad portion 501 can be separated from each other. The amount of heat generated by the heater wire portion 504 of the heater electrode 500a in a region between the heater pad portion 502 and the heater pad portion 502 can be sufficiently secured, and the temperature distribution uniformity on the adsorption surface S1 of the ceramic plate 100 is prevented from being lowered. can do.

  In the above embodiment, the heater wire portion 504 of the heater electrode 500 includes the first specific circumferential portion 513 and the second specific circumferential portion 523, but the heater wire portion 504 of the heater electrode 500 is It may not include at least one of the first specific circumferential portion 513 and the second specific circumferential portion 523. In the above embodiment, the second linear portion 542 is adjacent to the first linear portion 531 without passing through other portions of the heater wire portion 504 of the heater electrode 500, but such a configuration is not necessarily required. Need not be.

  In the above embodiment, the sectional area of the first heater pad part 501 and the sectional area of the second heater pad part 502 need not be larger than the sectional area of the heater wire part 504 for all the heater pad parts. It suffices if there is at least one location where the cross sectional area of the heater pad portion is larger than the cross sectional area of the heater wire portion 504.

  In the above embodiment, each heater electrode 500 is connected to a pair of power supply terminals (first power supply terminal 21 and second power supply region 52) via a pair of conductive regions (first conductive region 51 and second conductive region 52) in the driver electrode 50. Although connected to the second power supply terminal 22), each heater electrode 500 may be connected to a pair of power supply terminals without passing through the driver electrode 50. That is, the electrostatic chuck 10 may not include the driver electrode 50 and the power supply side vias 41 and 42. Further, the driver electrode 50 includes a plurality of pairs of conductive regions that are electrically connected to the pair of power supply terminals 21 and 22, respectively, and part of the plurality of heater electrodes 500 is electrically connected to the pair of conductive regions. May be electrically connected to another pair of conductive regions.

  In the above embodiment, each of the first heater side via 61, the second heater side via 62, the first power supply side via 41, and the second power supply side via 42 is constituted by a single via. It may be configured by a group of a plurality of vias. FIG. 9 is an explanatory diagram schematically showing the configuration of the heater electrode 500b in a modified example. In the heater electrode 500b of the modification shown in FIG. 9, the first heater side via 61 and the second heater side via 62 are each configured by a group of three vias.

 Moreover, the setting aspect of the segment SE in the said embodiment can be changed arbitrarily. Further, the configuration of the heater electrode 500 described above need not be realized in all the heater electrodes 500 included in the electrostatic chuck 10, and may be realized in at least one heater electrode 500.

  In the above embodiment, each heater electrode 500 is disposed inside the ceramic plate 100, but each heater electrode 500 may be disposed between the ceramic plate 100 and the base member 200.

  In the above-described embodiment, a monopolar system in which one chuck electrode 400 is provided inside the ceramic plate 100 is employed, but a bipolar system in which a pair of chuck electrodes 400 is provided inside the ceramic plate 100 is employed. It may be adopted. Moreover, the material which forms each member in the electrostatic chuck 10 of the said embodiment is an illustration to the last, and each member may be formed with another material.

  In addition, the present invention is not limited to the electrostatic chuck 10 that holds the wafer W using electrostatic attraction, but other holding devices (for example, a heater device such as a CVD heater) that holds an object on the surface of a ceramic plate. Or a vacuum chuck).

10: electrostatic chuck 11: first terminal hole 12: second terminal hole 21: first power supply terminal 22: second power supply terminal 31: first electrode pad 32: second electrode pad 41 : First power supply side via 42: second power supply side via 50: driver electrode 51: first conductive region 52: second conductive region 61: first heater side via 62: second heater side via 100 : Ceramic plate 120: Concave portion 200: Base member 210: Refrigerant flow path 220: Through hole 300: Adhesive layer 320: Through hole 400: Chuck electrode 500: Heater electrode 501: First heater pad portion 502: Second heater pad Portion 504: Heater wire portion 510: First via side portion 511: Circumferential portion 512: Linear portion 513: First specific circumferential portion 520: Second via side portion 521: Circumferential portion 522: Linear portion 523: Second specific circumferential portion 530: First connection portion 531: First linear portion 540: Second connection portion 542: Second linear shape Part 550: Folded part

Claims (4)

A ceramic plate having a substantially circular planar first surface;
A heater electrode which is a resistance heating element disposed in each segment when at least a part of the ceramic plate is divided into a plurality of segments arranged in a circumferential direction centering on a center point of the first surface. A heater electrode comprising: a pair of heater pad portions constituting both ends of the heater electrode; and a linear heater wire portion connecting the pair of heater pad portions;
A pair of power supply terminals;
A first via that is provided for each of the heater electrodes and electrically connects one heater pad portion of the pair of heater pad portions and one power supply terminal of the pair of power supply terminals;
Provided for each of the heater electrodes, arranged in a position aligned with the first via in the circumferential direction, and the other heater pad portion of the pair of heater pad portions and the other power supply terminal of the pair of power supply terminals. A second via for electrical connection;
A holding device for holding an object on the first surface of the ceramic plate,
The cross-sectional area of the pair of heater pad portions is larger than the cross-sectional area of the heater wire portion,
The heater wire portion of the specific heater electrode that is at least one of the heater electrodes includes a plurality of folded portions positioned in a region between the one heater pad portion and the other heater pad portion in the circumferential direction. A holding device. The holding device according to claim 1, wherein
The heater wire portion of the specific heater electrode is a first circumferential portion substantially parallel to the circumferential direction, and is aligned with the one heater pad portion in the circumferential direction, and the one heater A holding device comprising a first circumferential portion located in a region opposite to the other heater pad portion with respect to the pad portion. The holding device according to claim 2,
The heater wire portion of the specific heater electrode is a second circumferential portion substantially parallel to the circumferential direction, and is aligned with the other heater pad portion in the circumferential direction, and the other heater A holding device comprising a second circumferential portion located in a region opposite to the one heater pad portion with respect to the pad portion. In the holding device according to any one of claims 1 to 3,
The heater wire portion of the specific heater electrode is
A first via side portion connected to the one heater pad portion, and a plurality of circumferential shapes substantially parallel to the circumferential direction in a region not overlapping with the one heater pad portion in the circumferential direction A first via side portion including a portion;
A second via-side portion connected to the other heater pad portion, and a plurality of circumferential shapes substantially parallel to the circumferential direction in a region not overlapping the other heater pad portion in the circumferential direction A second via side portion including the portion;
A first connecting portion for connecting the first via side portion and the plurality of folded portions, wherein the plurality of circumferential portions and the second portion of the first via side portion in the circumferential direction; A first connecting portion including a first linear portion substantially orthogonal to the circumferential direction in a region between the plurality of circumferential portions of the via-side portion of
A second connecting portion that connects the second via-side portion and the plurality of folded-back portions, wherein the plurality of circumferential portions of the first via-side portion and the second in the circumferential direction; In the region between the plurality of circumferential portions of the via-side portion, the second linear portion substantially orthogonal to the circumferential direction, and the other portion of the heater wire portion of the specific heater electrode A second connecting part including a second linear part adjacent to the first linear part without interposing,
A holding device.

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