JP4819549B2 - Electrostatic chuck - Google Patents

Description

  The present invention relates to an electrostatic chuck used for fixing a semiconductor wafer, correcting flatness, conveying, etc. in an etching apparatus, an ion implantation apparatus, an electron beam exposure apparatus, and the like, which are used when manufacturing a wafer on a semiconductor, for example. .

  Conventionally, for example, in a semiconductor manufacturing apparatus, a semiconductor wafer (for example, a silicon wafer) is fixed and processing such as dry etching is performed, the semiconductor wafer is sucked and fixed to correct warpage, or the semiconductor wafer is sucked and transported. An electrostatic chuck is used for the purpose of, for example.

  As this type of electrostatic chuck, there is known an electrostatic chuck in which a disk-shaped ceramic body in which a suction electrode is embedded and a disk-shaped aluminum base are joined and integrated. There is also known an electrostatic chuck in which a heating element is embedded in a ceramic body for the purpose of heating a semiconductor wafer (see Patent Document 1).

An electrostatic chuck provided with this heating element is required to have a uniform temperature distribution on the surface on which the semiconductor wafer is heated in order to increase the processing accuracy of the semiconductor wafer. That is, if the temperature of the semiconductor wafer varies, for example, the etching processing accuracy deteriorates, so that the heating element uniformly heats the entire surface of the semiconductor wafer.
JP 2004-71647 A (page 4, FIG. 1)

  However, the above-described aluminum base is provided with a through-hole P3 penetrating in the plate thickness direction, for example, as shown in FIG. 10 in order to provide a terminal for flowing current to the adsorption electrode P1 and the heating element P2. In the portion of the through hole P3, the aluminum base P4 and the ceramic body P5 are not in direct contact with each other, which may cause inconvenience.

  That is, for example, in the method of heating the ceramic body P5 and simultaneously cooling the aluminum base P4 for the purpose of instantaneously changing the temperature of the ceramic body P5 during the etching process, the aluminum base P4 and the ceramic body P5 are directly connected. In the portion of the through hole P3 that does not contact, there is a problem that the temperature of the ceramic body P5 rises locally due to the heating of the heating element P2, and the temperature distribution of the ceramic body P5 deteriorates.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electrostatic chuck capable of making the temperature distribution of the ceramic body uniform.

  (1) The invention of claim 1 includes a ceramic body integrated so as to cover the through-hole with respect to the metal base having the through-hole, and an adsorption electrode and heat generation inside the ceramic body. In the electrostatic chuck in which the body is arranged, the projection area obtained by projecting the through hole of the metal base onto the ceramic body side and the area center of gravity of the projection area as a similar center are enlarged three times by the similarity ratio. And the outer region excluding the inside of the projection region, and the heating element so that the heat generation amount per unit area in the projection region is 50% or less of the heat generation amount per unit area in the outer region. It is characterized by arranging.

  The present invention shows the configuration of a ceramic body of an electrostatic chuck, and this ceramic body is used integrally with a metal base (having a higher thermal conductivity than the ceramic body). In addition, this electrostatic chuck is capable of attracting a processing / working object (work) such as a wafer on a semiconductor by electrostatic attraction and heating it by a heating element.

  Particularly in the present invention, since the heating element is disposed inside the ceramic body so that the heating value per unit area in the projection region is 50% or less of the heating value per unit area in the outer region, the through hole The temperature of the ceramic body corresponding to (projection area) does not rise excessively.

  That is, for example, during the etching process, when the method of heating the ceramic body and simultaneously cooling the metal base is performed for the purpose of instantaneously changing the temperature of the ceramic body, the metal base and the ceramic body are in direct contact with each other. In the through hole that does not, the heat of the ceramic body is difficult to escape to the metal base side, and thus the temperature of the ceramic body in the projection area of the through hole tends to rise locally. Is less than the amount of heat generated in the outer region on the outer peripheral side, so that the temperature rise in that portion is small.

  Therefore, since the temperature of the ceramic body in the projection region of the through hole does not rise locally, the temperature distribution of the ceramic body (particularly the temperature distribution on the surface of the ceramic body on the workpiece side) can be made uniform. Thereby, since the whole workpiece | work can be heated uniformly, there exists an effect that the process precision etc. of a workpiece | work improve.

  Here, the area centroid is the centroid of the area of the projection area when the projection area is viewed from the projection direction. For example, when the projection area of the through-hole is a circle having a diameter T, the outer area is an annular area having the same center and excluding the projection area from a circle having a diameter 3T.

  In addition, a plate-shaped thing is mentioned as a metal base or a ceramic body, and a through-hole which penetrates a metal base in the thickness direction is mentioned as a through-hole. Moreover, when covering a through-hole with a ceramic body, what covers the whole area of the opening part by the side of the ceramic body of a through-hole, or what covers a part is mentioned.

  (2) In the invention of claim 2, when the heating element is formed with the same material, thickness, and width in the projection area and the outer area, the area per unit area of the heating element in the projection area is determined as the outer area. It is characterized by being 50% or less of the area per unit area of the heating element in the region.

The present invention exemplifies a case where the heating element in the projection area and the heating element in the outer area are formed of similar heating elements of the same material and shape.
(3) The invention of claim 3 includes a ceramic body integrated so as to cover the through-hole with respect to the metal base having the through-hole, and an adsorption electrode and heat generation inside the ceramic body. In the electrostatic chuck in which the body is disposed, the heating element is disposed avoiding a projection region in which the through hole of the metal base is projected to the ceramic body side.

  In the present invention, the heating element is disposed inside the ceramic body so as to avoid the projection area in which the through hole is projected to the ceramic body side. Therefore, the temperature of the ceramic body in the portion corresponding to the through hole (projection area) Does not rise excessively.

  As described above, when the method of cooling the metal base at the same time by heating the ceramic body is performed, the heat of the ceramic body escapes to the metal base side in the through hole where the metal base and the ceramic body are not in direct contact. Therefore, the temperature of the ceramic body in the projection area of the through hole is likely to rise locally. However, in the present invention, since the heating element is not arranged in the projection area of the through hole, the temperature rise in that portion is small. .

Therefore, since the temperature distribution of the ceramic body can be made uniform, the entire workpiece can be heated uniformly, and thus there is an effect that the machining accuracy of the workpiece is improved.
(4) In the invention of claim 4, when the heating element is formed in a linear shape, the heating element is formed in a substantially U shape in the vicinity of the projection region, and the convex side of the substantially U shape. Is the projection region side.

  In the present invention, when a linear heating element is arranged near the projection area, the heating element is arranged so as to bend in a substantially U shape in the vicinity of the projection area. As a result, the heating element can be arranged so as to be spot-like while avoiding the projection area.

  As a method of arranging the heating element so as to avoid the projection area, for example, it is conceivable to arrange the heating element extending so as to pass over the projection area or its vicinity in the width direction. At that time, there is a fear that the heating element becomes dense in the gathered portion (depending on the gathered state) and the temperature rises, but in the present invention, there is no such fear.

(5) The invention of claim 5 is characterized in that the heating element is arranged at a distance of 1 mm or more from the projection region.
In the present invention, since the heating element is disposed sufficiently away from the projection region, the temperature distribution of the ceramic body can be made uniform uniformly.

(6) The invention of claim 6 is characterized in that the ceramic body and the metal base are integrated.
The present invention shows an electrostatic chuck in which a ceramic body and a metal base are integrated by bonding or the like.

(7) The invention of claim 7 is characterized in that the ceramic body is made of alumina.
The present invention exemplifies a preferable material of the ceramic body. In addition to alumina, aluminum nitride, yttria, or the like can be used.
(8) In the invention according to claim 8, the ceramic body includes a recess communicating with the through hole of the metal base, a metallized layer formed in the recess, a conductive pattern connected to the metallized layer, and the conductive body. And a via connected to the pattern.
The present invention illustrates a preferred configuration of the ceramic body.
(9) The invention of claim 9 is characterized in that the inner diameter of the through hole is larger than the inner diameter of the recess.
The present invention illustrates a preferred configuration of the ceramic body.

  Next, an example (example) of the best mode of the present invention will be described.

  a) First, the structure of the electrostatic chuck of this embodiment will be described. 1 is a perspective view showing a part of the electrostatic chuck in a broken state, and FIG. 2 is an explanatory view showing a cross section AA of the electrostatic chuck in FIG.

  As shown in FIG. 1, the electrostatic chuck 1 of the present embodiment is capable of attracting a semiconductor wafer 5 as a heating target (workpiece) on the upper attracting surface (chuck surface) 3 side of FIG. A disk-shaped ceramic body 7 (for example, diameter 300 mm × thickness 3 mm) and a disk-shaped metal base (aluminum base) 9 made of a disk-shaped aluminum alloy (for example, diameter 340 mm × thickness 20 mm) are joined.

  The ceramic body 7 and the aluminum base 9 are arranged on the main surface side (in the vertical direction in the figure), that is, on the main surface (ceramic side bonding surface) 11 opposite to the chuck surface 3 side of the ceramic body 7. The main surface (metal side bonding surface) 13 of the aluminum base 9 is bonded and integrated with the entire surface by silicon resin so that they face each other. That is, the plate-like (disc-like) electrostatic chuck 1 is configured by being integrated so as to be laminated in the thickness direction of each other.

The ceramic body 7 has an alumina-based sintered body as a base, and the exposed surface side (the side opposite to the aluminum base 9) is the chuck surface 3.
Inside the ceramic body 7, a pair of attracting electrodes (electrostatic electrodes: internal electrodes) 15 and 17 mainly made of tungsten are disposed on the chuck surface 3 side, and tungsten is mainly disposed on the aluminum base 9 side. A linear heating element 19 made of is arranged. The heating element 19 is formed in a spiral shape so as to almost uniformly cover the entire surface (on the arranged plane) (see FIG. 4).

  On the other hand, the aluminum base 9 has a larger diameter than the ceramic body 7 so that the entire ceramic body 7 is placed, and the aluminum base 9 has a coolant channel 21 for cooling the aluminum base 9. Is provided. Incidentally, the thermal conductivity of the aluminum base 9 is larger than the thermal conductivity of the ceramic body 7.

  Further, the electrostatic chuck 1 penetrates in the cooling gas flow path 25 from the chuck surface 3 of the ceramic body 7 to the back surface (base surface) 23 of the aluminum base 9, that is, in the thickness direction of the electrostatic chuck 1. Cooling gas flow paths 25 are provided at six locations.

  As shown in an enlarged view in FIG. 2, a plurality of recesses 27, 29, and 31 that are open to the aluminum base 9 side are provided on the aluminum base 9 side of the ceramic body 7. The plurality of through holes 33, 35, and 37 that penetrate the aluminum base 9 in the thickness direction are communicated with each other. In addition, the cylindrical concave portions 27 to 31 and the cylindrical through holes 33 to 37 have a common central axis, and the inner diameters of the through holes 33 to 37 are set larger than the inner diameters of the concave portions 27 to 31. .

  A cylindrical internal connection terminal 39 is joined to the concave portion 27 to a metallized layer 41, and this metallized layer 41 is (electrically) connected to one end of the heating element 19 via a conductive pattern 43 and a via 45. It is connected. In addition, the other recessed part 28 (refer FIG. 4) connected to the other end of the heat generating body 19 is formed similarly.

  In addition, cylindrical internal connection terminals 47 and 49 are joined to the metallization layers 51 and 53 in the recesses 29 and 31, and the metallization layers 51 and 53 are electrically connected via vias 46 and 48. D) connected to the internal electrodes 15, 17.

  b) Next, the principal part of the electrostatic chuck 1 of the present embodiment will be described. 3A is an enlarged sectional view showing a main part (for example, the vicinity of the concave portion 27) of the electrostatic chuck 1, and FIG. 3B is an explanatory view showing a projection area of the through hole 33. FIG. FIG. 6 is a plan view showing a pattern of a heating element 19.

As shown in FIG. 3A, in this embodiment, the heating element 19 is arranged so as to avoid the projection region T above the through hole 33 of the aluminum base 9 (on the ceramic body 7 side), for example.
Specifically, the heating element 19 is arranged so as to avoid a region (large projection region DT) wider than the circular projection region T by 1 mm or more in the radial direction.

  Further, as shown in FIG. 3B, the heating element 19 extends linearly in the left-right direction in the vertical direction (in the figure) of the projection region T, but is projected in the left-right direction of the projection region T. In the vicinity of the region T, it is symmetrically bent (with the projection region T side convex) and is bent in a substantially U shape so as not to overlap the projection region T.

  Therefore, the overall shape of the heating element 19 is as shown in FIG. That is, the heating element 19 avoids the pair of recesses 29 and 31 (for electrical connection of the internal electrodes 15 and 17) in the center portion, that is, the through holes 35 and 37 corresponding to the pair of recesses 29 and 31. Arranged to avoid.

  Further, it is arranged so as to avoid the pair of recesses 27 and 28 on the left and right (for electrical connection for the heating element 19), that is, to avoid the through holes 33 and 34 corresponding to the pair of recesses 27 and 28. .

  Further, the heating element 19 is formed so as to avoid the cooling gas passage 25 as well. That is, as shown in FIG. 1, the cooling gas flow path 25 includes a through hole 24 that penetrates the ceramic body 7 and a through hole 26 that penetrates the aluminum base 9 (having a larger diameter than the through hole 24). Therefore, the heating element 19 is wired so as to avoid the projection area of the through hole 26 having a large diameter.

c) Next, the manufacturing method of the electrostatic chuck 1 of the present embodiment will be described with reference to FIG.
(1) As a raw material, alumina powder as a main component: 92% by weight, MgO: 1% by weight, CaO: 1% by weight, SiO ₂ : 6% by weight are mixed and wetted by a ball mill for 50 to 80 hours. After pulverization, it is dehydrated and dried.

  (2) Next, methacrylic acid isobutyl ester: 3% by weight, butyl ester: 3% by weight, nitrocellulose: 1% by weight, dioctyl phthalate: 0.5% by weight were added to this powder, and trichlor was further added as a solvent. -Add ethylene and n-butanol and mix with a ball mill to form a fluid slurry.

(3) Next, this slurry is defoamed under reduced pressure and then poured into a flat plate and slowly cooled, and the solvent is diffused to form first to fifth alumina green sheets 51 to 59 having a thickness of 0.8 mm. .
In the first to fifth alumina green sheets 51 to 59, through holes 61 to 69 for forming the cooling gas flow path 25 are formed at six locations, respectively. Further, the third to fifth alumina green sheets 55 to 59 are formed with two through holes 75 to 79 for forming the recesses 29 and 31 for the internal electrodes 15 and 17 respectively. Further, the fifth alumina green sheet 59 is provided with two through holes 81 for forming the recesses 27 and 28 for the heating element 19 at two locations.

(4) Further, a tungsten powder is mixed into the raw material powder for the alumina green sheet, and is made into a slurry by the same method as described above to obtain a metallized ink.
(5) On the second alumina green sheet 53, the conductive patterns 71 and 73 (indicated by the oblique lines in the figure) for both internal electrodes 15 and 17 are printed by the usual screen printing method using the metallized ink. To do.

  (6) Further, a conductive pattern of the heating element 19 is printed on the fourth alumina green sheet 57 by a normal screen printing method using a well-known tungsten paste (as shown in FIG. 4).

(7) Next, the first to fifth alumina green sheets 51 to 59 are aligned so that the respective through holes coincide with each other, and thermocompression bonded to form a laminated sheet having an overall thickness of about 5 mm. .
The internal electrodes 15, 17 and the heating element 19 are drawn out to the back surfaces of the alumina green sheets 53, 57 by vias 45, 46, 48, and connected to the conductive patterns as necessary to form the recesses 27-31. Make it exposed.

(8) Next, the thermocompression-bonded laminated sheet is cut into a predetermined disc shape (for example, an 8-inch size disc shape).
(9) Next, the cut sheet is fired at 1400 to 1600 ° C. in a reducing atmosphere. Since the size is reduced by about 20% by this firing, the thickness of the ceramic body 7 after firing is about 4 mm.

(10) After firing, the entire thickness of the ceramic body 7 is reduced to 3 mm by polishing, and the flatness of the chuck surface 3 is reduced to 30 μm or less.
(11) Next, metallized layers 41, 51, 53 are formed on the conductive patterns and vias exposed in the recesses 27 to 31, and nickel plating is applied to the metallized layers 41, 51, 53.

(12) Next, the internal connection terminals 39, 47, 49 are brazed or soldered to complete the ceramic body 7.
(13) On the other hand, separately from the manufacturing process of the ceramic body 7 described above, the aluminum base 9 is manufactured by a well-known manufacturing process and processed into the predetermined dimensional shape (disk shape).

(14) Then, the ceramic body 7 and the aluminum base 9 are joined and integrated using silicon resin. Thereby, the electrostatic chuck 1 is completed.
d) Next, the effect of the present embodiment will be described.

  In the electrostatic chuck 1 of the present embodiment, the heating element 19 is arranged so as to avoid the projection region T in which the through holes 33 to 37 are projected on the ceramic body 7 side. The temperature of the ceramic body 7 in the projection area T) does not rise excessively.

  That is, for example, when performing a method of heating the ceramic body 7 and simultaneously cooling the aluminum base 9 for the purpose of instantaneously changing the temperature of the ceramic body 7 during the etching process, the aluminum base 9 and the ceramic body 7 In the through holes 33 to 37 that are not in direct contact with each other, the heat of the ceramic body 7 is difficult to escape to the aluminum base 9 side, and thus the temperature of the ceramic body 7 in the projection region T of the through holes 33 to 37 is locally increased. In this embodiment, since the heating element 19 is not arranged in the projection region T of the through holes 33 to 37, the temperature rise in that portion is small.

  Therefore, since the temperature of the ceramic body 7 in the projection region T of the through holes 33 to 37 does not rise locally, the temperature distribution of the ceramic body 7 can be made uniform. Thereby, since the whole semiconductor wafer 5 can be heated uniformly, there exists an effect that the processing precision etc. of the semiconductor wafer 5 improve.

  In particular, in this embodiment, the heating element 19 is arranged at a distance of 1 mm or more from the projection area T. Therefore, compared with the case where the heating element 19 is arranged away from the projection area T, the temperature distribution of the ceramic body 9 is increased. It can be made uniform uniformly.

  In this embodiment, the linear heating element 19 is arranged near the projection area T, and the heating element 19 is arranged so as to be bent in a substantially U shape in the vicinity of the projection area T. Accordingly, the heating elements 19 can be arranged so as to avoid the projection region T and be spotted without densely wiring the heating elements 19. Thereby, the temperature distribution of the semiconductor wafer 5 can be made more uniform.

Next, the second embodiment will be described, but the description of the same parts as the first embodiment will be omitted.
As shown in FIG. 6, the electrostatic chuck 101 of the present embodiment has basically the same configuration as that of the first embodiment, but the shape of the cooling gas flow path 103 is different.

  In this embodiment, the cooling gas flow path 103 includes not only flow paths 107 and 109 extending in the thickness direction of the ceramic body 105 but also a flow path (horizontal direction in the figure) 113 extending in parallel with the chuck surface 111. .

The heating element 115 is disposed above the cooling gas passage 113 extending in the lateral direction, and the internal electrodes 117 and 119 are disposed above the heating element 115.
Further, in the cooling gas flow path 103, a flow path 109 that penetrates the ceramic body 105 in the thickness direction is a through-hole 121 that penetrates the ceramic body 105 and a penetration that penetrates the aluminum base 123 (having a larger diameter than the through-hole 121). The hole 125 is comprised.

Accordingly, the heating element 115 is arranged so as to avoid the projection region of the through-hole 125 having a large diameter, as in the first embodiment.
As shown in FIG. 7, the cooling gas flow path 133 is bent inside the ceramic body 131, and the cooling gas flow path 133 does not penetrate the electrostatic chuck 135 in the thickness direction (linearly). Similarly, the heating element 141 is disposed so as to avoid a projection region above the through hole 139 (on the ceramic body 131 side) of the aluminum base 137.

  Also in the present embodiment, the same effects as in the first embodiment can be obtained.

Next, although Example 3 will be described, description of the same parts as those in Example 1 will be omitted.
As shown in FIG. 8, the electrostatic chuck 150 of this embodiment has a heating element 155 disposed so as to avoid the projection region T (or the large projection region DT) corresponding to the through hole 153 of the aluminum base 151.

  That is, if the heating elements 155 are arranged in parallel (to other heating elements 156), the projection area T may be bypassed, that is, the projection area T may be concave when the projection area T is crossed. The heating element 155 is bent and arranged so as to be curved.

  This also provides the effect of making the temperature of the ceramic body 157 described above uniform.

Next, Example 4 will be described, but the description of the same part as Example 1 will be omitted.
As shown in FIG. 9, the electrostatic chuck 161 of the present embodiment has basically the same configuration as that of the first embodiment, but the formation position of the heating element 163 is different.

  In this embodiment, the heating element 163 is also formed inside the projection area T, but the heating element 163 is set so that the temperature of the ceramic body 165 in the projection area T does not rise excessively.

  Specifically, a circular projection area T having a diameter of 10 mm, and an outer diameter of 30 mm (excluding the projection area T with the area ratio centroid of the projection area T being a similar center and the projection area being enlarged three times by the similarity ratio) When the outer region ST is separated from the outer region ST, the heating element 163 is configured so that the heat generation amount per unit area in the projection region T is 50% or less (for example, 45%) of the heat generation amount per unit area in the outer region ST. Is formed.

  In other words, the heating element 163 has the same material (thousands of ceramic added to tungsten), thickness (20 μm), and width (1.5 mm) in the projection region T and the outer region ST. The area per unit area of the heating element 163 is set to 50% or less (for example, 45%) of the area per unit area of the heating element in the outer region ST.

Also in the present embodiment, the same effects as in the first embodiment can be obtained.
In addition, this invention is not limited to the said Example at all, and it cannot be overemphasized that it can implement with a various aspect in the range which does not deviate from the summary of this invention.

(1) For example, the present invention can be applied not only to the bipolar electrostatic chuck as in the first embodiment but also to a monopolar electrostatic chuck.
(2) Moreover, although the tunnel which flows a refrigerant | coolant is provided in the aluminum base, you may provide the tunnel which flows a heating medium separately from (or with it).

  (3) Further, in the first embodiment, the cooling gas flow path is used as a through hole into which the lift pin is inserted. However, the present invention can also be applied to a through hole dedicated to the lift pin. In other words, since the diameter of the through hole on the aluminum base side of the through hole for the lift pin is usually larger than the diameter of the through hole on the ceramic body side, the heating element is arranged so as to avoid the projection area of the through hole on the aluminum base side. .

  (4) In the first embodiment, one spiral heating element is formed, but two or more heating elements may be formed separately on the inner side (center axis) side and the outer side. For example, on the inner side, a spiral-like inner heating element similar to that of the first embodiment is formed, and on the outer side (outer peripheral side) of the inner heating element, an outer side such as a ring or a spiral is formed so as to go around the inner heating element. A heating element may be formed. Thereby, ON / OFF and temperature control of an inner side heat generating body and an outer side heat generating body can be performed separately.

FIG. 3 is a perspective view showing a part of the electrostatic chuck according to the first embodiment. It is explanatory drawing which shows the AA cross section (longitudinal cross section) of the electrostatic chuck of Example 1. FIG. The principal part of the electrostatic chuck of Example 1 is enlargedly shown, (a) is the longitudinal cross-sectional view, (b) is explanatory drawing which shows arrangement | positioning of planes, such as a heat generating body. FIG. 3 is an explanatory diagram showing a pattern of a heating element in Example 1. It is explanatory drawing which decomposes | disassembles and shows the ceramic body in Example 1. FIG. FIG. 6 is a perspective view showing a part of the electrostatic chuck of Example 2 with a part thereof broken. It is sectional drawing which fractures | ruptures and shows another electrostatic chuck in the vertical direction. The principal part of the electrostatic chuck of Example 3 is shown enlarged, (a) is a longitudinal cross-sectional view of the BB direction of (b), (b) is explanatory drawing which shows arrangement | positioning of planes, such as a heat generating body. It is. FIG. 10 is an explanatory diagram illustrating a planar arrangement of a heating element or the like in the electrostatic chuck of Example 4. It is explanatory drawing of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 101, 135, 150, 161 ... Electrostatic chuck 3 ... Chuck surface 5 ... Semiconductor wafer 7, 105, 131, 157, 165 ... Ceramic body 9, 123, 137, 151 ... Metal base (aluminum base)
15, 17, 117, 119 ... internal electrodes 19, 115, 141, 155, 156, 163 ... heating elements 27, 28, 29, 31 ... recesses 24, 26, 33, 35, 37, 34, 61, 63, 65 , 67, 69, 75, 77, 79, 121, 125, 139, 153...

Claims (9)

With a ceramic body integrated so as to cover the through-hole with respect to the metal base having the through-hole,
In an electrostatic chuck in which an adsorption electrode and a heating element are arranged inside the ceramic body,
A projection region in which the metal-based through-hole is projected on the ceramic body side, and an outer region excluding the inside of the projection region while the projection region is enlarged three times by the similarity ratio with the area centroid of the projection region as the center of similarity And
The electrostatic chuck according to claim 1, wherein the heating element is arranged so that a heat generation amount per unit area in the projection region is 50% or less of a heat generation amount per unit area in the outer region. When the heating element is formed with the same material, thickness, and width in the projection region and the outer region,
2. The electrostatic chuck according to claim 1, wherein an area per unit area of the heating element in the projection area is 50% or less of an area per unit area of the heating element in the outer area. With a ceramic body integrated so as to cover the through-hole with respect to the metal base having the through-hole,
In an electrostatic chuck in which an adsorption electrode and a heating element are arranged inside the ceramic body,
An electrostatic chuck characterized in that the heating element is arranged avoiding a projection region in which the through hole of the metal base is projected to the ceramic body side. In the case where the heating element is formed in a linear shape, the heating element is formed in a substantially U shape in the vicinity of the projection area, and the convex side of the substantially U shape is on the projection area side. the electrostatic chuck according to any one of the claims 1 to 3. Wherein a distance from the projection area 1mm or more, the electrostatic chuck according to any one of the claims 1-4, characterized in that a said heating element. The electrostatic chuck according to any one of the claims 1-5, characterized in that integrated with the metal base and the ceramic body. The ceramic body is an electrostatic chuck according to any one of the claims 1-6, characterized in that it consists of alumina. The ceramic body includes a recess communicating with the through hole of the metal base, a metallized layer formed in the recess, a conductive pattern connected to the metallized layer, and a via connected to the conductive pattern. The electrostatic chuck according to claim 1, wherein the electrostatic chuck is characterized in that: The electrostatic chuck according to claim 8, wherein an inner diameter of the through hole is larger than an inner diameter of the concave portion.

Images