JP2017228360A - Heating member and electrostatic chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a heating member and an electrostatic chuck, capable of easily performing an elastic connection to a terminal pad from an external part even when a ceramic substrate or the like is constricted during burning.SOLUTION: A plurality of terminal pads 81 is arranged along a peripheral direction of a ceramic substrate 17 in a plane view, and each terminal pad along a radial direction of the ceramic substrate 17 has a shape longer than that along the peripheral direction. Therefore, even when the position of each terminal pads 81 is shifted due to burning, the terminal pad can be easily electrically connected to a conductive member of a connector. That is, since each terminal pad 81 has the long shape in the radial direction, a terminal pin can be arranged at a regulation position on each terminal pad 81 even when the position is shifted due to burning. Therefore, each terminal pad 81 and the conductive member can be easily electrically connected.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a heating member such as a ceramic heater that can heat a workpiece such as a semiconductor wafer, and an electrostatic chuck including the heating member.

  Conventionally, in a semiconductor manufacturing apparatus, a process such as dry etching (for example, plasma etching) is performed on a semiconductor wafer (for example, a silicon wafer). In order to increase the accuracy of this dry etching, it is necessary to securely fix the semiconductor wafer. As a fixing means for fixing the semiconductor wafer, an electrostatic chuck for fixing the semiconductor wafer by electrostatic attraction is used. Yes.

  Specifically, in an electrostatic chuck, for example, an adsorption electrode is provided in a ceramic substrate, and an electrostatic attractive force generated when a voltage is applied to the adsorption electrode is used to attach a semiconductor wafer to the ceramic substrate. Adsorb to the upper surface (adsorption surface). In the electrostatic chuck, for example, a metal base is bonded to the lower surface (bonding surface) of the ceramic substrate.

  Some electrostatic chucks have a function of adjusting (heating or cooling) the temperature of the semiconductor wafer attracted to the attracting surface. For example, there is a technique of heating a semiconductor wafer on an adsorption surface by disposing a heating element in a ceramic substrate and heating the ceramic substrate with the heating element.

  Furthermore, in order to precisely heat the electrostatic chuck, a ceramic heater in which a ceramic substrate is divided into a plurality of heating zones (heating regions) has been developed. Specifically, there is also a ceramic heater with a multi-zone heater in which a heating element (partial heating element) capable of independently heating each heating zone is arranged in each heating zone to improve the temperature adjustment function of the ceramic substrate. It has been proposed (see Patent Document 1).

  Further, in recent years, a ceramic heater in which two layers of heating elements are arranged in the thickness direction inside the ceramic substrate has been developed for the purpose of adjusting the temperature more accurately with respect to the ceramic heater with a multi-zone heater. .

  In such a ceramic heater in which a large number of heating elements are arranged, it is necessary to provide a large number of terminal portions for supplying electric power to each heating element from the outside. Therefore, for example, as shown in FIG. 11, there is known one in which a large number of terminal portions P3 are arranged along the circumferential direction on the surface opposite to the suction surface of the ceramic heater P1 (and therefore the ceramic substrate P2).

  The terminal portion P3 includes, for example, a circular terminal pad P4 formed on the ceramic heater P1, and a terminal pin P5 joined to the terminal pad P4 (inserted into the insertion hole of the connector). .

  The terminal pad P4 is formed, for example, by forming a terminal pattern with a conductive paste on a ceramic green sheet and simultaneously firing the terminal pattern and the ceramic green sheet.

JP 2005-166354 A

  However, in the above-described prior art, the ceramic substrate P2 and the like contract during firing (particularly in the radial direction), and therefore it is not easy to place the terminal pad P4 (and thus the terminal pin P5) at a predetermined position. was there.

  That is, the terminal pin P5 needs to be arranged in accordance with the position (specified position) of the insertion hole of the connector. However, when the ceramic substrate P2 contracts by firing, the position of the terminal pad P4 on which the terminal pin P5 is provided is shifted. For this reason, when the terminal pin P5 is joined to the terminal pad P4, the terminal pin P5 may not be disposed at a specified position corresponding to the connector.

  As a countermeasure, it is conceivable to increase the terminal pad P4. In this case, however, another problem arises that it is difficult to arrange a large number of terminal pads P4 at target positions corresponding to the specified positions.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heating member and an electrostatic chuck that can be easily electrically connected to the terminal pad from the outside even when the ceramic substrate shrinks by firing. There is.

  (1) A first aspect of the present invention is a ceramic substrate having a first main surface on which a workpiece is mounted and a second main surface opposite to the first main surface, and having electrical insulation. And a heating part that is disposed inside the ceramic substrate and generates heat when energized, and the heating part relates to a heating member having a plurality of heating elements that can be adjusted in temperature independently.

  The heating member includes a plurality of terminal pads electrically connected to the plurality of heating elements on the second main surface of the ceramic substrate. The plurality of terminal pads are arranged along the circumferential direction of the ceramic substrate in a plan view when the ceramic substrate is viewed from the thickness direction, and the length along the radial direction of the ceramic substrate is longer than the length along the circumferential direction. Has a longer shape.

  In the first aspect, since the terminal pad is used to supply power to the heating element, the terminal pad (specifically, for example, the terminal pin) is supplied with electric power from the outside, for example, the electrical conductivity of the connector. The members are connected. Accordingly, it is necessary to provide the terminal pad at a predetermined position (that is, a predetermined position where the terminal pad can be connected to the conductive member which is the counterpart member).

  By the way, when the ceramic substrate and the terminal pad are formed by simultaneous firing, the ceramic substrate contracts more in the radial direction than in the circumferential direction, so that the position of the terminal pad deviates from the target position (specified position). Sometimes.

  On the other hand, in the first aspect, a plurality of terminal pads are arranged along the circumferential direction of the ceramic substrate in a plan view, and the radial direction of the ceramic substrate (that is, the ceramic substrate) from the length along the circumferential direction. Since the length along the direction along which the shrinkage deviation toward the center direction is larger) is longer, the electrical connection with the conductive member of the connector is possible even when the position of the terminal pad is deviated from the specified position by firing, for example. Easy.

  That is, since the terminal pad has a shape that is long in the radial direction, the terminal pad can be disposed at a position facing the conductive member of the connector, for example, even if there is a positional shift due to firing. Therefore, it is possible to easily obtain an electrical connection between the terminal pad and the conductive member even if there is a positional shift due to firing.

  In addition, since the terminal pads have a shape that is long in the radial direction and short in the circumferential direction, when a plurality of terminal pads are arranged, many terminal pads are arranged in the circumferential direction even in a small area (compared to a circular terminal pad). It can be arranged densely.

  Furthermore, the heating member (and hence the ceramic substrate) is often required to have a uniform temperature distribution in the plane direction. For example, the terminal pads are not regularly arranged (for example, so as to cross the heating elements arranged concentrically). ) When arranged along the radial direction, it is not easy to adjust the arrangement and shape of the heating elements in order to make the temperature distribution uniform. That is, it is necessary to confirm the temperature distribution at each position where the terminal pads are arranged, which is troublesome.

  On the other hand, in the first aspect, since a plurality of terminal pads are arranged along the circumferential direction of the ceramic substrate, the arrangement of the terminal pads is regular, and therefore, with respect to temperature changes caused by the arrangement of the terminal pads. Adjustment is also easy. That is, since the terminal pads are regularly arranged along the circumferential direction, the temperature changes are almost the same, and therefore, the effort for making the temperature distribution uniform can be reduced.

  (2) In the second aspect of the present invention, the ceramic substrate includes a plurality of vias for electrically connecting the heat generating portion and the terminal pad, and the plurality of vias connected to the terminal pad are arranged in the radial direction. Are arranged along.

  In the second aspect, since the plurality of vias connected to the terminal pad are arranged along the long radial direction of the terminal pad dimension, even if the terminal pad is displaced by firing (or the terminal pad itself is Even when contracted, a plurality of vias can be easily placed in the terminal pad.

(3) In the third aspect of the present invention, an internal wiring layer is disposed between the heating element and the terminal pad, and the internal wiring layer and the terminal pad are connected by a plurality of vias.
In the third aspect, since the internal wiring layer and the terminal pad are connected by a plurality of vias, electrical connection between the internal wiring layer and the terminal pad can be reliably obtained.

(4) In the fourth aspect of the present invention, another member having conductivity is joined to the terminal pad.
In the fourth aspect, since another member (other conductive member) such as a terminal pin is joined to the terminal pad, for example, it can be easily connected to a connector using this terminal pin or the like.

(5) A fifth aspect of the present invention is an electrostatic chuck including the heating member according to any one of the first to fourth aspects and including an electrostatic electrode on a ceramic substrate.
The electrostatic chuck can attract and heat the workpiece.

In addition, as this invention, the structure of following (a)-(d) is also employable.
(A) The other member having conductivity is a heating member which is a metal pin.
(B) A heating member having a line (linear portion) extending in the circumferential direction as a configuration of the heat generating portion.

(C) A heating member having a configuration in which the plurality of heating elements are arranged in the circumferential direction as the configuration of the heat generating portion.
(D) A heating member having a plurality of heat generating portions arranged at different positions in the thickness direction as a configuration of the heat generating portion.

<Each configuration of the present invention will be described below>
The circumferential direction is a direction that turns around the center of the ceramic substrate in plan view. Here, the center of the ceramic substrate means the center of gravity, and when the ceramic substrate is circular, it means the center of the circle. That is, when the ceramic substrate is circular, the circumferential direction means the circumferential direction.

  The radial direction is a direction from the center of the ceramic substrate toward the outer periphery in plan view. Here, the center of the ceramic substrate means the center of gravity, and when the ceramic substrate is circular, it means the center of the circle. That is, when the ceramic substrate is circular, the radial direction means the radial direction.

  A ceramic substrate is a substrate (plate-shaped member) containing ceramic as a main component (50% by mass or more). Examples of the ceramic material include aluminum oxide (alumina), aluminum nitride, yttrium oxide (yttria), and the like.

The ceramic substrate used for the electrostatic chuck is an electrically insulating ceramic insulating plate.
-A main surface is the surface which makes the edge part in the thickness direction of a board | plate material (board | substrate).

The terminal pad is a conductive layer made of, for example, tungsten or molybdenum.
The heating part (and hence the heating element) is a resistance heating element that generates heat when energized, and examples of the material of the heating element include tungsten, tungsten carbide, molybdenum, molybdenum carbide, tantalum, and platinum.

  -Examples of the material of the electrostatic electrode include tungsten and molybdenum.

FIG. 3 is a perspective view showing a partially broken electrostatic chuck of the embodiment. It is sectional drawing which fractures | ruptures the electrostatic chuck of embodiment and shows the one part in the thickness direction. It is a top view which shows the 1st heat generating body and heating area | region of the 1st heat generating part of a ceramic heater. It is a top view which shows the 2nd heat generating body and heating area | region of the 2nd heat generating part of a ceramic heater. It is explanatory drawing which a partly fracture | ruptures and expands and shows the structure of a connector and its periphery. It is a top view which shows arrangement | positioning of the terminal pad in the 2nd main surface of a ceramic heater. It is sectional drawing which fractures | ruptures a ceramic heater in the thickness direction and shows a terminal pad, a via | veer, an internal wiring layer, etc. (A) is explanatory drawing which shows the internal wiring layer etc. in the XX cross section of FIG. 7, (b) is explanatory drawing which shows the terminal pad in the YY cross section of FIG. 7, (c) is the 2nd main surface. It is a top view which shows the terminal pad and terminal pin in. It is sectional drawing which fractures | ruptures the ceramic heater of other embodiment in the thickness direction, and shows a terminal pad, a via | veer, an internal wiring layer, etc. The modification of other embodiment is shown typically, (a) is sectional drawing which fractures | ruptures the electrostatic chuck of modification 1 in the thickness direction, (b) is the electrostatic chuck of modification 2 in the thickness direction FIG. 7C is a cross-sectional view showing the fracture of the electrostatic chuck of Modification 3 in the thickness direction, and FIG. 8D is a cross-sectional view of the ceramic heater of Modification 4 broken in the thickness direction. is there. It is explanatory drawing of a prior art.

[1. Embodiment]
Here, as an embodiment, for example, an electrostatic chuck capable of attracting and holding a semiconductor wafer is taken as an example.
[1-1. overall structure]
First, the structure of the electrostatic chuck of this embodiment will be described.

  As shown in FIG. 1, the electrostatic chuck 1 of the present embodiment is an apparatus that adsorbs a semiconductor wafer 3 that is a workpiece on the upper side of FIG. 1, and includes a ceramic heater (heating member) 5, a metal base 7, and the like. Are laminated and joined by the adhesive layer 9.

  The upper surface (upper surface: adsorption surface) of the ceramic heater 5 in FIG. 1 is the first main surface A, and the lower surface is the second main surface B. Further, the upper surface of the metal base 7 is the third main surface C, and the lower surface is the fourth main surface D.

  Among these, the ceramic heater 5 has a disk shape and is composed of a ceramic substrate (insulating substrate) 17 provided with an adsorption electrode (electrostatic electrode) 11, a first heat generating portion 13, a second heat generating portion 15, and the like. . The adsorption electrode 11, the first heat generating part 13, and the second heat generating part 15 are embedded in the ceramic substrate 17.

  The metal base 7 has a disk shape larger in diameter than the ceramic heater 5 and is joined to the ceramic heater 5 coaxially. The metal base 7 is provided with a flow path (cooling path) 19 through which a cooling fluid (refrigerant) flows in order to cool the ceramic substrate 17 (and thus the semiconductor wafer 3). As the cooling fluid, for example, a cooling liquid such as a fluorinated liquid or pure water can be used.

  The electrostatic chuck 1 is provided with a plurality of lift pin holes 21 or the like into which lift pins (not shown) are inserted so as to penetrate the electrostatic chuck 1 in the thickness direction. The lift pin hole 21 is also used as a cooling gas flow path (cooling gas hole) supplied to the first main surface A side to cool the semiconductor wafer 3.

  In addition to the lift pin holes 21, a cooling gas hole (not shown) may be provided. As the cooling gas, for example, an inert gas such as helium gas or nitrogen gas can be used.

Next, each configuration of the electrostatic chuck 1 will be described in detail with reference to FIG.
<Ceramic heater>
As schematically shown in FIG. 2, the ceramic heater 5 (and hence the ceramic substrate 17) has a third main surface C of the metal base 7 on the second main surface B side by an adhesive layer 9 made of indium, for example. It is joined to the side.

  The ceramic substrate 17 is formed by laminating a plurality of ceramic layers (not shown), and is an alumina sintered body mainly composed of alumina. The alumina sintered body is an insulator (dielectric).

  Inside the ceramic substrate 17, as will be described in detail later from above in FIG. 2, a plurality of first heating elements 23 and second heating parts 15 constituting the adsorption electrode 11, the first heating part 13 are configured. A plurality of second heating elements 25 and the like are arranged.

  Among these, the adsorption electrode 11 is electrically connected to a known electrode terminal (not shown) for applying a voltage. In addition, the first and second heating elements 23 and 25 are electrically connected to the power supply terminal 29 or the connector 31 via internal wiring or the like, which will be described later.

  Specifically, the first heating element 23 has one end of the first heating element 23 connected to the via 33 or the common internal wiring layer 35a and the other end connected to the via 33 or individual so that the temperature can be controlled independently. Are connected to the internal wiring layer 35b. The common internal wiring layer 35a and the individual internal wiring layer 35b are connected to the connector 31 via a terminal portion 39 provided on the second main surface B side surface of the ceramic substrate 17, as will be described in detail later. Are connected to the respective conductive members 41 (see FIG. 5).

  On the other hand, the second heating element 25 has one end of the second heating element 25 connected to the via 33 or the common internal wiring layer 35c and the other end connected to the via 33 or individual so that the temperature can be controlled independently. It is connected to the internal wiring layer 35d. The common internal wiring layer 35c and the individual internal wiring layer 35d are connected to the power feeding terminal 29 via the terminal portion 51 provided on the surface of the ceramic substrate 17 on the second main surface B side. .

  The terminal unit 51 includes, for example, a terminal pad 53. The via 33 and the internal wiring layers 35a, 35b, 35c, and 35d (collectively referred to as 35) are made of, for example, tungsten.

<Metal base>
The metal base 7 is made of metal made of aluminum or an aluminum alloy. In addition to the cooling path 19 and the lift pin hole 21, the metal base 7 is formed with a through portion 55 that is a through hole in which the electrode terminal, the power supply terminal 29, the connector 31 and the like are disposed.

  Note that an internal hole extending from the fourth main surface D to the inside of the ceramic heater 5 is provided on the fourth main surface D side of the electrostatic chuck 1 so as to accommodate the power supply terminal 29, the connector 31, and the like. A plurality of 57 are provided, and the penetrating portion 55 of the metal base 7 constitutes a part of the internal hole 57.

In addition, in the inner hole 57 that accommodates the electrode terminal and the power feeding terminal 29, an insulating cylinder 59 having electrical insulation is disposed so as to surround the outer periphery of each terminal 29.
The connector 31 is accommodated in the internal hole 57 (for the connector 31) as it is.

<Adsorption electrode>
The adsorption electrode 11 is composed of, for example, an electrode having a circular planar shape. When the electrostatic chuck 1 is used, a DC high voltage is applied to the adsorption electrode 11, thereby generating an electrostatic attractive force (adsorption force) for adsorbing the semiconductor wafer 3. It is used to adsorb and fix the semiconductor wafer 3. In addition to the above, various known configurations (monopolar or bipolar electrodes, etc.) can be employed for the adsorption electrode 11. The adsorption electrode 11 is made of a conductive material such as tungsten.

<First heating part and second heating part>
Next, the 1st heat generating part 13 and the 2nd heat generating part 15 are demonstrated.
The second heat generating unit 15 is a main heater that generates a larger amount of heat than the first heat generating unit 13, and the first heat generating unit 13 is a sub-heater. The first and second heating elements 23 and 25 are resistance heating elements made of a metal material (such as tungsten) that generates heat when voltage is applied and current flows.

  As shown in FIG. 2, each first heating element 23 of the first heating unit 13 is on the same plane (first plane H <b> 1) on the second main surface B side (downward in FIG. 2) from the adsorption electrode 11. (See FIG. 3).

On the other hand, each 2nd heat generating body 25 of the 2nd heat generating part 15 is arrange | positioned on the same plane (2nd plane H2: refer FIG. 4) between the 1st heat generating part 13 and the 2nd main surface B. FIG. ing.
Accordingly, the first heat generating portion 13 and the second heat generating portion 15 are arranged so as to be overlapped in a plan view as viewed from the thickness direction of the ceramic substrate 17 (and hence the electrostatic chuck 1).

Hereinafter, each heat generating part 13 and 15 will be described in detail.
First, the arrangement of the plurality of first heat generating elements 23 constituting the first heat generating portion 13 on the first plane H1 will be described with reference to FIG.

The ceramic substrate 17 is provided with a plurality of heating zones 61 concentrically in a plan view so that each region in the first plane H1 can be heated (thus adjusting the temperature).
In each heating zone 61, one or a plurality of heating regions 63 are set. In each heating region 63, the first heating element 23 (substantially circular or substantially U-shaped) is arranged corresponding to the shape of each heating region 63. In FIG. 3, only a part of the first heating elements 23 is shown.

Next, the arrangement of the plurality of second heat generating elements 25 constituting the second heat generating portion 15 on the second plane H2 will be described with reference to FIG.
The ceramic substrate 17 is provided with a plurality of heating zones 71 concentrically in plan view so that each region in the second plane H2 can be heated (and thus temperature controlled).

  In each heating zone 71, one or a plurality of heating regions 73 are set. In each heating region 73, the second heating element 25 (substantially circular or substantially U-shaped) is arranged corresponding to the shape of each heating region 73.

<Connector>
Next, the connector 31 and the surrounding configuration will be described.
As shown in FIGS. 2 and 5, a plurality of terminal pads 81 connected to the vias 33 are provided on the bottom surface 57 a (the upper surface in FIG. 5) of the internal hole 57 in which the connector 31 is disposed. . The terminal pad 81 is made of tungsten, for example.

  The terminal pads 81 are provided corresponding to the internal wiring layers 35 respectively connected to the multiple first heating elements 23 so as to supply electric power to the multiple first heating elements 23.

  On each terminal pad 81, a terminal pin 83 connected to the connector 31 is erected and brazed. This terminal pin 83 has a cylindrical pin 83b erected at the center of a disk-shaped substrate 83a. The terminal pad 39 and the terminal pin 83 constitute a terminal portion 39.

  The connector 31 is disposed at the back of the internal hole 57 (upper in FIG. 5) and has a resin-made tip connector part 85 having electrical insulation, and the same as that of the open part of the internal hole 57 (lower in FIG. 5). The rear end connector portion 87 (see FIG. 2), and the front end connector portion 85 and the rear end connector portion 87 are connected to the cable portion 89.

The distal end connector portion 85 is a substantially rectangular parallelepiped, and the distal end surface 91 includes a large number of pin holes 93 into which terminal pins 83 (specifically, pins 83b) can be inserted.
A cylindrical conductive member 41 that is in contact with the pin 83 b is disposed on the inner peripheral surface of the pin hole 93. The conductive member 41 is electrically connected to a conductive member (not shown) of the rear end connector portion 87 by a conductive material (not shown) extending to the cable portion 89 side.

  Therefore, by pushing the tip connector portion 85 of the connector 31 into the internal hole 57, the terminal pins 83 of the terminal portions 39 and the conductive members 41 of the connector 31 can be connected to obtain electrical continuity.

FIG. 5 shows a state in which three terminal pins 83 are connected to the connector 31, but actually, a plurality of rows (for example, four rows) of terminal pins 83 are formed on the bottom surface 57a perpendicular to the paper surface. Since they are arranged, for example, a total of 12 terminal pins 83 are connected to the connector 31.
[1-2. Terminal Pad Configuration]
Next, the structure of the terminal pad 81 which is the principal part of this embodiment is demonstrated.

As shown in FIG. 6, a large number of terminal pads 81 are arranged on the surface of the second main surface B of the ceramic heater 5 (and hence the ceramic substrate 17).
Specifically, the terminal pads 81 are arranged in a plurality of rows (for example, 3 rows) along the circumferential direction (circumferential direction) of the ceramic substrate 17 in plan view, and a large number of terminal pads 81 are arranged in each row. Several are arranged.

  The terminal pad 81 has a length along the radial direction (radial direction) of the ceramic substrate 17 from the length along the circumferential direction (length in the vertical direction in FIG. 6) in plan view (the horizontal direction in FIG. 6). Has a longer shape (oval shape). The length in the circumferential direction is, for example, 1 mm, and the length in the radial direction is, for example, 2 mm.

  That is, when the ceramic heater 5 is fired, the terminal pad 81 has a shape in a direction (circumferential direction) perpendicular to the radial direction, rather than a length in a direction (radial direction) having the largest shrinkage rate in plan view. The length is set to be short.

  In FIG. 6, only one row of the plurality of rows of terminal pads 81 is shown, and only a part of the row of terminal pads 81 is shown. In FIG. 6, the position of the via 33 connected to the terminal pad 81 directly or indirectly is shown by a one-dot chain line as will be described later.

  As shown in FIG. 7, the terminal pad 81 is connected to the opposing internal wiring layer 35e by a plurality of (for example, two) vias 33 provided in the ceramic substrate 17, and further, this internal wiring layer 35e. Are connected to another internal wiring layer 35f facing each other by a plurality of (for example, two) vias 33.

  That is, as shown in FIG. 8A, the first main surface A side (front side) of the internal wiring layer 35e is connected to the other internal wiring layer 35f by the via 33, and the internal wiring layer 35e The main surface B side (back side) of 2 is connected to the terminal pad 81 by a via 33.

  Further, as shown in FIG. 8B, the first main surface A side (front side) of the terminal pad 81 is connected to the internal wiring layer 35e by a plurality of vias 33, as shown in FIG. 8C. Thus, the terminal pin 83 is brazed to the fourth main surface D side (back side) of the terminal pad 81.

The plurality of vias 33 connected to the terminal pad 81 and the internal wiring layer 35 are arranged in a line along the longitudinal direction (radial direction) of the terminal pad 81 and the internal wiring layers 35e and 35f.
The internal wiring layers 35e and 35f are electrically connected to the first heating element 23 through vias 33 and the like.

As the shape of the internal wiring layers 35e and 35f, for example, a planar shape similar to that of the terminal pad 81 can be adopted. In this case, the internal wiring layers 35e and 35f and the terminal pad 81 overlap in plan view.
[1-3. Production method]
Next, a method for manufacturing the electrostatic chuck 1 of the present embodiment will be briefly described.

(1) As a raw material of the ceramic substrate 17, the main components of Al ₂ O ₃ : 92 wt%, MgO: 1 wt%, CaO: 1 wt%, and SiO ₂ : 6 wt% are mixed to form a ball mill. Then, after wet grinding for 50 to 80 hours, dehydrated and dried.

(2) Next, a solvent or the like is added to the powder and mixed with a ball mill to form a slurry.
(3) Next, this slurry is degassed under reduced pressure, and then poured into a flat plate shape and gradually cooled, and the solvent is diffused to form each alumina green sheet (corresponding to each ceramic layer).

And the space used as the lift pin hole 21 grade | etc., And also the through hole used as the via | veer 33 are opened to a required location with respect to each alumina green sheet.
(4) Further, a tungsten powder is mixed in the raw material powder for the alumina green sheet to form a slurry to obtain a metallized ink.

  (5) Then, in order to form the adsorption electrode 11, the first and second heating elements 23, 25, the internal wiring layer 35, the terminal pads 53, 81, etc., the adsorption electrode 11, Each pattern is printed by an ordinary screen printing method on an alumina green sheet corresponding to the formation location of the first and second heating elements 23 and 25, the internal wiring layer 35, the terminal pads 53 and 81, and the like. In order to form the via 33, the through hole is filled with metallized ink.

(6) Next, the alumina green sheets are aligned so that necessary spaces such as lift pin holes 21 are formed, and thermocompression-bonded to form a laminated sheet.
(7) Next, each thermocompression-bonded laminated sheet is cut into a predetermined shape (that is, a disc shape).

(8) Next, each cut laminated sheet is fired in a reducing atmosphere in the range of 1400 to 1600 ° C. (for example, 1550 ° C.) for 5 hours (main firing) to produce each alumina sintered body. .
(9) After firing, necessary processing such as processing on the first main surface A side is performed on each alumina sintered body to produce the ceramic substrate 17.

(10) Next, terminal pins 83 are brazed to the terminal pads 81 on the second main surface B of the ceramic substrate 17.
(11) Separately, the metal base 7 is manufactured. Specifically, the metal base 7 provided with the internal holes 57 and the like is formed by cutting the metal plate.

(12) Next, the metal base 7 and the ceramic substrate 17 are joined and integrated.
(13) Next, the connector 31 and the like are arranged corresponding to each internal hole 57 to complete the electrostatic chuck 1.
[1-4. effect]
Next, the effect of this embodiment will be described.

  In the present embodiment, since the terminal pad 81 is used to supply power to the first heating element 23, the terminal pin 83 of the terminal pad 81 is electrically connected to the connector 31 in order to supply power from the outside. The member 41 is connected. Therefore, it is necessary to provide the terminal pad 81 at a predetermined position (specified position).

  Therefore, in the present embodiment, a plurality of terminal pads 81 are arranged along the circumferential direction of the ceramic substrate 17 in plan view, and the length along the radial direction of the ceramic substrate 17 is longer than the length along the circumferential direction. Has a longer shape.

  Therefore, when the ceramic substrate 17 and the terminal pad 81 are simultaneously fired, the terminal pin 83 can be disposed at a predetermined position on the terminal pad 81 even when the ceramic substrate 17 or the like is greatly contracted in the radial direction. .

  That is, since the terminal pad 81 has a shape that is long in the radial direction, the terminal pin 83 can be disposed at a predetermined position on the terminal pad 81 even when the position is displaced in the radial direction by firing. That is, the terminal pin 83 can be disposed at a position facing the conductive member 41 of the connector 31. Therefore, it is possible to easily obtain the electrical connection between the terminal pad 81 and the conductive member 41 even if there is a positional shift due to firing.

  Further, in the present embodiment, the terminal pad 81 has a shape that is long in the radial direction and short in the radial direction. Therefore, when a plurality of terminal pads 81 are arranged, even if the area is small (compared to a circular terminal pad), Many terminal pads 81 can be densely arranged in the direction.

  Furthermore, in the present embodiment, since a plurality of terminal pads 81 are arranged along the circumferential direction of the ceramic substrate 17, there is regularity in the arrangement of the terminal pads 81, and thus the temperature change caused by the arrangement of the terminal pads 81. Adjustment (ie, adjustment of the arrangement and shape of the heating elements 23 and 25) is also easy.

  That is, since the terminal pads 81 are regularly arranged along the circumferential direction in which the heating elements 23 and 25 (arranged in an annular shape) extend, the temperature changes by the terminal pads 81 are almost the same. Therefore, it is possible to reduce the labor of the adjustment for making the temperature distribution uniform.

Further, in the present embodiment, the plurality of vias 33 connected to the terminal pad 81 are arranged along the radial direction of the terminal pad 81 having a long dimension, so that the plurality of vias 33 can be easily arranged. .
[2. Other Embodiments]
It goes without saying that the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the present invention.

  (1) For example, in the embodiment, the example in which the connector is connected to the terminal pad (specifically, the terminal pin) connected to the first heating element has been described, but the terminal pad connected to the second heating element is also the first It is good also as a structure (shape and arrangement | positioning) similar to the terminal pad of 1 heat generating body. Further, a terminal pin or the like may be provided on the terminal pad of the second heating element so as to be connected to the connector as in the above embodiment.

  (2) The connector is not limited to the connector of the above embodiment, and the number of terminal pins connected to one connector is not limited to the above embodiment. For example, one terminal pin can be connected to one connector.

(3) Furthermore, the internal wiring layer connected to the terminal pad via the via may be different from the position and shape of the terminal pad in plan view.
For example, as shown in FIG. 9, the internal wiring layer 35 g connected to the terminal pad 81 via the via 33 is arranged so as to extend to the center side from the end of the terminal pad 81 on the center side (left side in the figure). It may be.

  Further, the other internal wiring layer 35h connected to the internal wiring layer 35g via the via 33 is arranged so as to extend to the center side from the end portion on the center side (left side in the figure) of the internal wiring layer 35g. May be. In this case, the via 33 connecting both the internal wiring layers 35g and 35h may be arranged so as not to overlap the terminal pad 81 in plan view.

  Or, conversely (not shown), the internal wiring layer 35g may be disposed so as to extend to the outer peripheral side from the end portion of the terminal pad 81 on the outer peripheral side (on the opposite side to the center side). Further, the other internal wiring layer 35h may be arranged so as to extend to the outer peripheral side with respect to the end portion on the outer peripheral side of the internal wiring layer 35g.

  (4) In the embodiment, the terminal pin is joined to the terminal pad. However, another conductive member (for example, a lead wire) is joined to the terminal pad, and electric power is supplied to each heating element via the conductive member. May be.

  Alternatively, it is also possible to employ a method in which a pin (for example, biased by a spring) is disposed on the connector side without joining other members to the terminal pad, and the tip of the pin or the like is brought into contact with the terminal pad to obtain conduction. .

  (5) Also, for example, as shown in Modification 1 in FIG. 10A, the first heat generating portion 13 is arranged in the ceramic substrate 17, and the outside of the ceramic substrate 17 (that is, the second main surface B side). The second heat generating part 15 may be arranged in

  (6) Further, as shown in Modification 2 in FIG. 10B, for example, the second heat generating portion 15 includes a plurality of layers (for example, the upper layer 15 a on the first main surface A side and the second layer arranged in the thickness direction). You may comprise by 2 layers of the lower layer 15b by the side of the main surface B. Moreover, you may comprise the 1st heat generating part 13 by multiple layers.

Alternatively, only one heating element may be used as the heating part, such as either the first heating part or the second heating part.
(7) Further, as shown in Modification 3 in FIG. 10C, the present invention can be applied to the electrostatic chuck 1 that does not include the metal base 7. That is, the present invention can also be applied to the electrostatic chuck 1 including the ceramic heater 5 and the adsorption electrode 11, the first heat generating portion 13, and the second heat generating portion 15.

(8) Furthermore, the present invention can be applied to a ceramic heater that is not an electrostatic chuck.
For example, as shown in Modification 4 in FIG. 10 (d), the present invention can be applied to the ceramic heater 5 provided with the first heat generating portion 13 and the second heat generating portion 15 similar to those of the above embodiment in the ceramic substrate 17.

  (9) The configurations of the present embodiments can be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Electrostatic chuck 5 ... Ceramic heater 11 ... Electrode for adsorption (electrostatic electrode)
DESCRIPTION OF SYMBOLS 13 ... 1st heat generating part 15 ... 2nd heat generating part 17 ... Ceramic substrate 23 ... 1st heat generating body 25 ... 2nd heat generating body 17 ... Ceramic substrate 29 ... Connector 33 ... Via 35, 35a, 35b, 35c, 35d, 35e, 35f, 35g, 35h ... internal wiring layers 53, 81 ... terminal pads

Claims (5)

A ceramic substrate having a first main surface on which a workpiece is mounted and a second main surface opposite to the first main surface and having electrical insulation, and disposed inside the ceramic substrate A heating part that generates heat when energized, and
In the heating member having a plurality of heating elements capable of adjusting the temperature independently,
A plurality of terminal pads respectively electrically connected to the plurality of heating elements on the second main surface of the ceramic substrate;
The plurality of terminal pads are in a plan view of the ceramic substrate as viewed from the thickness direction,
A heating member, wherein a plurality of the ceramic substrates are arranged along a circumferential direction of the ceramic substrate, and a length along a radial direction of the ceramic substrate is longer than a length along the circumferential direction. Inside the ceramic substrate, with a plurality of vias for electrically connecting the heat generating portion and the terminal pad,
The heating member according to claim 1, wherein the plurality of vias connected to the terminal pads are arranged along the radial direction.   The internal wiring layer is disposed between the heating element and the terminal pad, and the internal wiring layer and the terminal pad are connected by the plurality of vias. Heating member.   The heating member according to claim 1, wherein another member having conductivity is bonded to the terminal pad.   An electrostatic chuck comprising the heating member according to claim 1, and an electrostatic electrode provided on the ceramic substrate.