JP2011243881A - Electrostatic chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic chuck which can prevent cavity generation, high resistance, and generation of electrical disconduction inside a conductive layer, which can improve bond strength, and which can improve long-term reliability of the whole device.SOLUTION: An electrostatic chuck 1A device comprises: a plate substrate 2A made of ceramic which has yttria as its main ingredient; a concavity 3A which opens on one principal surface of this substrate; a conductive layer 4A exposed to the bottom surface 9A of the concavity and made of platinum and ceramic which has yttria as its main ingredient; an electrode terminal 5A positioned to stand in the concavity and connected electrically to the conductive layer; a connection intermediate layer 6A formed between the surface 10A of the conductive layer and the electrode terminal and containing no less than 93 volume % of platinum.

Description

  The present invention relates to an electrostatic chuck, and more particularly, to prevent generation of cavities in a conductive layer, increase in resistance, occurrence of electrical non-conduction, and decrease in mechanical strength, and improve bonding strength, and The present invention relates to an electrostatic chuck capable of improving the long-term reliability of the entire apparatus.

  Conventionally, various electrostatic chucks have been considered.

  For example, Patent Document 1 states that “an electrostatic chuck having an electrostatic electrode inside an insulator, the insulator having a laminated structure in which ceramic green sheets are laminated, pressed and fired. In order to supply a gas for controlling the temperature of the member to be adsorbed to the adsorption surface of the insulator, a gas flow path having a gas outlet on the adsorption surface is provided inside the insulator. The electrostatic chuck is characterized in that the insulator is made of a yttria sintered body in which a yttria green sheet mainly composed of yttria is used as the ceramic green sheet (patent) (See claim 1 of Document 1). Patent Document 2 states that “an electrostatic chuck having an electrostatic electrode inside an insulator, and the insulator is formed by laminating and firing a plurality of ceramic green sheets mainly composed of yttria. An electrostatic chuck characterized in that the electrostatic chuck is made of a laminated body (see claim 1 after correction of Patent Document 2) is disclosed.

  The “electrostatic chucks” described in Patent Documents 1 and 2 are technically that “the one having a gas flow path inside the insulator forming the electrostatic chuck has excellent corrosion resistance against halogen gas and plasma thereof”. It is described as having an effect (see paragraphs 0008 of Patent Documents 1 and 2).

  Patent Document 3 states that “in a bonded structure in which a metal is brazed through a brazing material layer, the brazing material layer is made of a brazing material mainly composed of gold and has a Vickers hardness (HV0.1) of 150. In addition to the above, there is described a “joint structure in which a metal is brazed, which is characterized in that a protective film of platinum is deposited on at least a joint surface of the metal with a brazing material layer” (Patent Document 3). (See claim 1). The “joint structure” described in Patent Document 3 is “Ni that adheres to or is contained in a metal such as a plating layer, a lead wire, a metal terminal, a pipe, and a ring body, diffuses into the brazing material layer mainly composed of gold. There is a technical effect that it can be performed ”(see paragraph 0019 in Patent Document 3).

  Patent Document 4 states that “an electrode is embedded in a ceramic base composed of a plurality of ceramic layers, a fixing hole for attaching an external terminal is formed on the back surface of the ceramic base, and the fixing is performed. In a power supply structure of a wafer holding device in which via holes filled with a conductive material are formed in several ceramic layers between a hole and the electrode so as to establish conduction, the power supply structure of the wafer holding device has a gap between the fixed hole and the electrode. A wafer characterized in that a conductive layer wider than the cross-sectional area of the fixing hole is laid in each ceramic layer to be electrically connected to the via hole of each ceramic layer, and the via hole positions of the adjacent ceramic layers are shifted from each other. "Feeding structure of holding device" is described (see claim 1 of Patent Document 4). The “power supply structure of the wafer holding device” described in Patent Document 4 describes “the thermal stress generated between the via hole and the ceramic substrate when the via terminal can be reliably conducted and the external terminal is brazed and fixed. It is possible to prevent the ceramic substrate from being damaged by absorbing the material "(see paragraph No. 0057 of Patent Document 4).

  However, compared to the conventional electrostatic chuck as described above, it further prevents voids in the conductive layer, increases resistance, generates electrical non-conduction, and lowers mechanical strength, and improves bonding strength. There has been a demand for an electrostatic chuck that can improve the long-term reliability of the entire apparatus.

JP 2008-147549 A JP 2008-205510 A JP 2001-199775 A Japanese Patent Laid-Open No. 9-213455

  The problem to be solved by the present invention is that it is possible to prevent the generation of cavities in the conductive layer, the increase in resistance, the occurrence of electrical non-conduction, and the decrease in mechanical strength, and to improve the bonding strength. An electrostatic chuck capable of improving the long-term reliability of the entire apparatus is provided.

Means for solving the problems are as follows:
(1) a plate-like substrate made of a ceramic mainly composed of yttria;
A recess opening in one main surface of the substrate;
A conductive layer formed of platinum and a ceramic mainly composed of yttria exposed on the bottom surface of the recess;
An electrostatic chuck having an electrode terminal disposed upright in the recess and electrically connected to the conductive layer,
An electrostatic chuck comprising a connection intermediate layer containing 93 vol% or more of platinum formed between the surface of the conductive layer and the electrode terminal;
(2) The electrostatic chuck according to (1), wherein the conductive layer is via-connected to an internal conductive layer disposed in the substrate.
(3) The concave portion is composed of a large-diameter portion on the opening side of the concave portion and a small-diameter portion subsequent thereto,
Secondary conductivity formed by extending from the surface of the connection intermediate layer formed on the surface of the conductive layer exposed on the bottom surface of the small diameter portion which is the bottom surface of the concave portion to the shelf portion which is the bottom surface of the large diameter portion. With layers,
The electrostatic chuck according to (1) or (2), wherein an electrode terminal is disposed standing on the shelf, and the secondary conductive layer and the electrode terminal are electrically connected.
(4) The concave portion is composed of a large-diameter portion on the opening side of the concave portion and a small-diameter portion subsequent thereto,
A small diameter portion side connection intermediate layer formed on the surface of the conductive layer exposed on the bottom surface of the small diameter portion, which is the bottom surface of the recess,
A large-diameter side connection intermediate layer formed on the surface of the conductive layer formed exposed on the shelf that is the bottom surface of the large-diameter portion in the same recess;
A secondary conductive layer that electrically connects both the surface of the small diameter part side connection intermediate layer and the surface of the large diameter part side connection intermediate layer, and
The secondary conductive layer formed on the surface of the large-diameter portion side connection intermediate layer, or the large-diameter portion-side connection intermediate layer and the electrode terminal are electrically connected (1) to (3) The electrostatic chuck according to any one of the above, and
(5) Any of (1) to (4), wherein the end of the connection intermediate layer formed on the surface of the conductive layer formed exposed on the bottom surface of the recess is isolated from the inner wall surface of the recess. Or an electrostatic chuck according to any one of the above.

  According to the present invention, since the connection intermediate layer contains 93% by volume or more of platinum, it is difficult for the platinum to move on the surface portion of the conductive layer, so that the generation of voids in the conductive layer can be prevented. As a result, prevention of high resistance, prevention of electrical non-conduction, and prevention of mechanical strength reduction are also achieved, and the bonding strength to the bonding means for bonding the connection intermediate layer and the electrode terminal is improved, and the entire apparatus It is possible to provide an electrostatic chuck capable of achieving improvement in long-term reliability.

  Further, according to the present invention, the conductive layer and the internal conductive layer are via-connected, the concave portion is provided with the large diameter portion and the small diameter portion, the secondary conductive layer is provided, or the end portion of the conductive layer and the concave portion Since the inner wall surface is isolated, it is possible to prevent the occurrence of cracks in the substrate, ensuring durability for long-term use, and as a result, long-term reliability of the entire device. It is possible to provide an electrostatic chuck capable of achieving the improvement.

FIG. 1 is a schematic sectional view showing an embodiment of the electrostatic chuck according to the present invention. FIG. 2 is a schematic cross-sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 3 is a schematic cross-sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 4 is a schematic sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 5 is a schematic cross-sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 6 is a schematic cross-sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 7 is a schematic cross-sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 8 is a schematic sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 9 is a schematic cross-sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 10 is a schematic sectional view showing another embodiment of the electrostatic chuck according to the present invention. FIG. 11 is a schematic sectional view showing another embodiment of the electrostatic chuck according to the present invention.

  An electrostatic chuck according to the present invention includes a plate-like substrate made of a ceramic whose main component is yttrium oxide (hereinafter, sometimes referred to as “yttria”), a concave portion opened on one main surface of the substrate, A conductive layer formed of platinum and a ceramic containing yttria as a main component, exposed on the bottom surface of the concave portion, and an electrode terminal disposed upright in the concave portion and electrically connected to the conductive layer; And a connecting intermediate layer containing 93% by volume or more of platinum formed between the surface of the conductive layer and the electrode terminal. An electrostatic chuck is an apparatus that can temporarily hold a semiconductor wafer by using static electricity that is normally generated by applying a voltage to a conductive layer.

  The electrostatic chuck according to the present invention will be described below with reference to the drawings showing embodiments.

  An electrostatic chuck 1A shown in FIG. 1 includes a base 2A, a recess 3A, a conductive layer 4A, an electrode terminal 5A, and a connection intermediate layer 6A.

  The base 2A is a plate-like member made of a ceramic whose main component is yttria. The base 2A is a ceramic sintered body having an insulating property and preferably having a laminated structure.

  As the shape of the substrate 2A, a disk shape is often adopted in principle, but as long as the purpose of the electrostatic chuck according to the present invention can be achieved and the semiconductor wafer can be temporarily held, There is no limitation, and for example, a plate having a polygonal plane shape, or a plate having a ring shape in the plane shape may be employed.

  Further, in the material of the base 2A, in addition to yttria as a main component, for example, calcium oxide, magnesium oxide, strontium oxide, barium oxide, or the like can be used as a sintering aid.

  As the size of the base 2A, when the base 2A is a disk, for example, the thickness is 1 mm to 10 mm and the diameter is 50 mm to 500 mm.

  The recess 3A is a hole that opens in one main surface 7A of the base 2A and is formed in the thickness direction of the base 2A. The recess 3A is a portion where an electrode terminal 5A described later is inserted from the opening 8A and the electrode terminal 5A is fixed in the recess 3A.

  The shape of the recess 3A is not particularly limited. For example, the opening 8A is circular, elliptical, or polygonal, and the cross-sectional shape from the opening 8A to the bottom surface 9A is the same as that of the opening 8A. Or the aspect etc. which are the groove | channels formed in one main surface 7A of the base | substrate 2A are employable. The size of the recess 3A is not limited as long as at least the opening 8A can insert an electrode terminal 5A described later. Specifically, for example, the circular opening 8A has a diameter of 5 mm or more and 30 mm or less. be able to. The depth of the recess 3A, that is, the distance from the opening 8A to the bottom surface 9A, which is the ceiling surface of the recess 3A in FIG. 1, is determined according to the position where the conductive layer 4A described later is disposed. The depth of the recess 3A is a distance from the opening 8A to the conductive layer 4A at the maximum.

  The conductive layer 4A is a conductive member formed so as to be exposed on the bottom surface 9A of the recess 3A. In the electrostatic chuck 1A, as shown in FIG. 1, the conductive layer 4A is partly embedded in the base 2A and partly exposed on the bottom surface 9A of the recess 3A. The conductive layer 4A contains platinum and a ceramic containing yttria as a main component.

  The content of platinum contained in the conductive layer 4A is preferably 40% by volume or more and 95% by volume or less because good conductivity can be secured. In addition, as the material other than platinum contained in the conductive layer 4A, for example, tungsten, molybdenum, and / or a ceramic mainly composed of yttria, which is a material for forming the base 2A, can be used. It is preferable to use platinum and a material for forming the base 2A as the material of the conductive layer 4A because the base 2A and the conductive layer 4A are likely to be in close contact when the conductive layer 4A is embedded in the base 2A. In addition, there is no restriction | limiting in particular as the magnitude | size of the conductive layer 4A, It is good that it is a grade which can be embed | buried in the base | substrate 2A. Furthermore, the shape of the conductive layer 4A may be any shape that can be exposed to the bottom surface 9A of the recess 3A. For example, a thin plate shape, a lump shape, a linear shape, or the like can be adopted.

  The electrode terminal 5A is a member that is arranged upright in the recess 3A and is electrically connected to the conductive layer 4A. As shown in FIG. 1, in the electrostatic chuck 1 </ b> A, one end of the electrode terminal 5 </ b> A is inserted into the recess 3 </ b> A and fixed to an intermediate connection layer 6 </ b> A described later. As the electrode terminal 5A, it is preferable to use a rod-shaped member having conductivity.

  As for the shape of the electrode terminal 5A, in order to ensure the ease of insertion into the recess 3A, it is preferable that at least a portion inserted into the recess 3A has a rod shape such as a columnar shape or a prism shape. The shape of the portion of the electrode terminal 5A that extends outside the recess 3A is appropriately determined according to the environment in which the electrostatic chuck 1A is installed, the environment in which it is used, the device connected to the electrostatic chuck 1A, and the like. Is done.

  When the electrode terminal 5A has a cylindrical shape, the diameter of the electrode terminal 5A is about 1 mm to 5 mm and the length is about 10 mm to 50 mm. Since it becomes easy, it is preferable.

  The material of the electrode terminal 5A may be any material having conductivity, and examples thereof include metals such as iron, nickel, cobalt, gold, silver, and copper, or alloys of these metals. As a material for the electrode terminal 5A, a material having a high electric conductivity and a low coefficient of thermal expansion is preferable, and the above alloy, for example, Kovar is suitable.

  The connection intermediate layer 6A is a member formed between the surface 10A of the conductive layer 4A and the electrode terminal 5A. Further, the connection intermediate layer 6A contains 93% by volume or more of platinum.

  The conductive layer may be heated to a high temperature of 1000 ° C. or higher in a reducing atmosphere during manufacture. In an electrostatic chuck without a connection intermediate layer, a metal component such as platinum contained in the conductive layer may move toward the surface of the conductive layer in the conductive layer. When the metal component and the ceramic component that were uniformly mixed in the raw material stage of the conductive layer are exposed to a high-temperature reducing atmosphere, the ceramic component hardly moves, whereas the metal component is activated. A region where the metal component exists inside the conductive layer so as to gather on the surface of the conductive layer so as to reduce the surface area may become a cavity. When a cavity exists in the conductive layer, the contact between platinum components in the conductive layer is cut off by the cavity, resulting in high resistance of the conductive layer and electrical non-conduction of the conductive layer. there is a possibility. Furthermore, moisture or the like may enter the cavities in the conductive layer and may not withstand long-term use of the entire electrostatic chuck device. In addition, when voids are generated in the conductive layer, the mechanical strength of the conductive layer may be reduced.

  On the other hand, when the connection intermediate layer 6A containing 93% by volume or more of platinum is provided on the surface 10A of the conductive layer 4A like the electrostatic chuck 1A, it is located outside when heated in the course of manufacture. The connecting intermediate layer 6A is exposed to a high-temperature reducing atmosphere. 6 A of connection intermediate | middle layers contain 93 volume% or more of platinum, and platinum has already gathered before a heating, Therefore The movement of platinum is suppressed. That is, when the connection intermediate layer 6A is provided on the surface 10A of the conductive layer 4A, no voids are generated in the conductive layer 4A and the connection intermediate layer 6A even when heated in a reducing atmosphere during the manufacturing process. Thus, it is possible to prevent the conductive layer 4A from increasing in resistance, the conductive layer 4A from being electrically disconnected, and the mechanical strength from being lowered. Further, when no void is generated in the conductive layer 4A, moisture or the like does not enter the conductive layer 4A, and the electrostatic chuck 1A can be used for a long time. Reliability will be improved.

  In the embodiment shown in FIG. 1, the connection intermediate layer 6A is formed so as to cover the surface 10A that is the exposed surface of the conductive layer 4A. In the electrostatic chuck according to the present invention, the connection intermediate layer only needs to be formed at least on the surface of the conductive layer and on the portion where the electrode terminal is disposed. That is, the end surface joined to the connection intermediate layer in the electrode terminal may be included in the region of the connection intermediate layer formed on the conductive layer.

  In the region where the connection intermediate layer is formed on the surface of the conductive layer, the end surface joined to the connection intermediate layer in the electrode terminal is included at least in the region of the connection intermediate layer formed on the conductive layer. Since the metal component contained in the conductive layer does not move, no cavity is generated in the conductive layer. Therefore, even if a void is generated in the conductive layer in the region where the connection intermediate layer is not formed on the surface of the conductive layer due to heating in a reducing atmosphere during manufacturing, the connection is made between the electrode terminal and the conductive layer. By forming the intermediate layer, the electrical connection between the electrode terminal and the conductive layer is maintained in a good state.

  However, when the connection intermediate layer 6A is formed so as to cover the entire surface of the conductive layer 4A as shown in FIG. 1, the resistance of the conductive layer 4A and the occurrence of electrical non-conduction are further increased. Since it can prevent reliably, it is preferable.

  The connecting intermediate layer 6A may be 100% by volume of platinum. Examples of components other than platinum that can be included in the connecting intermediate layer 6A include gold, ruthenium, rhodium, palladium, iridium, and these. Examples thereof include metals such as alloys and ceramics mainly composed of yttria contained in the substrate 2A.

  As shown in FIG. 1, the electrode terminal 5A is mechanically and electrically joined to the connection intermediate layer 6A by brazing. More specifically, the electrode terminal 5A is disposed so as to stand in the recess 3A, and is brazed by the brazing material 11A in a state where the electrode terminal 5A and the connection intermediate layer 6A are in contact with each other.

  The brazing material 11A used in the electrostatic chuck 1A may be any material that has good wettability with respect to both the connection intermediate layer 6A and the electrode terminal 5A and can be firmly bonded. For example, silver solder, copper solder, brass solder, phosphor copper solder, aluminum solder, and / or gold solder can be employed.

  In the electrostatic chuck according to the present invention, a single electrode type that generates static electricity by applying a voltage between the conductive layer and an external electrode disposed outside, and a pair of conductive layers are embedded, and the electrode Any type of bipolar type in which static electricity is generated by applying a voltage therebetween may be adopted.

  Here, a manufacturing method of the electrostatic chuck 1A shown in FIG. 1 will be described. The electrostatic chuck 1A described below is an aspect including a recess 3A having a circular horizontal cross-sectional shape when a plate-shaped electrostatic chuck is arranged so that the surface of the plate is horizontal.

First, a green sheet mainly composed of yttria is obtained by forming a slurry obtained by mixing yttria powder, an auxiliary agent, a binder, a dispersant, a solvent, and the like into a sheet shape by a doctor blade method or a calendar method. . At this time, the thickness of the green sheet may be about 0.1 to 1 mm. Next, the green sheet is cut into an appropriate size, and about 2 to 20 green sheets are laminated and pressed under conditions of, for example, 70 ° C. and 50 kgf / cm ² to obtain a green sheet laminate. Further, through holes for the recesses 3A are formed in some green sheet laminates by mechanical punching or drilling. The thickness of the green sheet, the diameter of the through hole, and the like may be determined in consideration of deformation and shrinkage due to firing after the size after firing is determined in advance.

  Furthermore, for example, platinum powder, yttria powder containing calcium carbonate, and an appropriate organic vehicle that is a mixture of organic substances such as a binder, a dispersant, and a solvent are kneaded to prepare a conductive layer paste. A conductive layer paste can be applied to the surface of the green sheet laminate by screen printing so that a desired conductive layer 4A is disposed.

  Subsequently, for example, a paste for connecting intermediate layer containing 100% by volume of platinum is prepared by kneading platinum powder and an appropriate organic vehicle. The connecting intermediate layer paste is applied to the surface 10A of the conductive layer 4A before firing, which is formed by applying the conductive layer paste. The region where the connection intermediate layer paste is applied may be determined in consideration of deformation and shrinkage due to firing after the size after firing is determined in advance. Thereby, the connection intermediate | middle layer 6A before baking is obtained.

Next, a green sheet laminate having through-holes is formed such that the green sheet laminate having no through-holes and formed with the conductive layer 4A and the connection intermediate layer 6A before firing becomes the bottom surface 9A. Further, the laminated holes are further laminated under the conditions of, for example, 70 ° C. and 50 kgf / cm ² while aligning the through holes at desired positions to be the recesses 3A, for example, both the left recesses 3A and the right recesses 3A in FIG. Crimp. The process of laminating and pressing the green sheet laminates is repeated until the desired thickness of the base body 2A before firing is reached. Further, it is formed into a desired shape such as a disk shape by end milling or the like. Thereby, the base 2A, the recess 3A, and the conductive layer 4A before firing are obtained.

  The base body 2A, the concave portion 3A, the conductive layer 4A, and the connection intermediate layer 6A that are obtained before firing are fired in the air at, for example, 1550 to 1650 ° C. for 1 to 5 hours. Furthermore, as a process for correcting the warp of the sintered body, the base 2A, the recess 3A, the conductive layer are heat-treated in a reducing atmosphere of hydrogen gas and nitrogen gas, for example, at 1400 to 1600 ° C. for 1 to 5 hours. 4A and the connection intermediate layer 6A can be obtained.

  Next, one end of the electrode terminal 5A made of Kovar, for example, is inserted into the recess 3A from the opening 8A of the recess 3A so that the axis of the electrode terminal 5A and the axis of the recess 3A are parallel. In a state where one end of the electrode terminal 5A is in contact with the recess 3A, the one end of the electrode terminal 5A is subjected to, for example, a brazing material 11A such as silver braze under a reducing atmosphere of, for example, hydrogen gas and nitrogen gas at 790 ° C. The contact portion between the portion and the recess 3A can be brazed. The brazing conditions can be appropriately determined according to the type of brazing material.

  Through the above steps, the electrostatic chuck 1A including the base 2A, the recess 3A, the conductive layer 4A, the electrode terminal 5A, and the connection intermediate layer 6A can be manufactured.

  The obtained electrostatic chuck 1A is coated so that the connecting intermediate layer paste covers the conductive layer paste, so that the connecting intermediate layer 6A containing a large amount of metal components even when heat-treated in a reducing atmosphere. Is only exposed to the atmosphere, and the conductive layer 4A to which the metal component can move is not exposed to the atmosphere, so that it is possible to prevent the generation of cavities due to the movement of the metal component in the conductive layer 4A. By preventing the generation of cavities, it is possible to prevent the electrical resistance of the conductive layer 4A from becoming too high and the electrical non-conduction of the conductive layer 4A from occurring. Moreover, the mechanical strength reduction of the conductive layer 4A can also be prevented by preventing the generation of voids in the conductive layer 4A.

  Further, since the connection intermediate layer 6A contains a larger amount of platinum than the conductive layer 4A, the connection intermediate layer 6A has higher wettability to the brazing material 11A of the connection intermediate layer 6A than the conductive layer 4A. It is possible to realize strong bonding between the terminal 5A and the connection intermediate layer 6A.

  Further, by preventing the generation of cavities in the conductive layer 4A, the increase in resistance, the occurrence of electrical non-conduction, and the decrease in mechanical strength, and by realizing the strong bonding between the electrode terminal 5A and the connection intermediate layer 6A The electrostatic chuck 1A can be used for a long time, and the long-term reliability of the entire apparatus is improved.

  Hereinafter, an embodiment of the electrostatic chuck according to the present invention, which is different from the electrostatic chuck 1A, will be described with reference to the drawings.

  The difference between the electrostatic chuck 1B shown in FIG. 2 and the electrostatic chuck 1A shown in FIG. 1 is that the conductive layer is via-connected to the internal conductive layer disposed in the substrate. Except for this difference, since the electrostatic chuck 1A and the electrostatic chuck 1B use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 2, in the electrostatic chuck 1B, the conductive layer 4B exposed on the bottom surface 9B of the recess 3B and the internal conductive layer 13B disposed in the base 2B are formed by the via connecting conductor portion 14B. Via connected. The internal conductive layer 13B is a conductor that is disposed substantially parallel to the conductive layer 4B and the bottom surface 9B of the recess 3B. The via connecting conductor portion 14B includes the conductive layer 4B, the internal conductive layer 13B, and the like. Is a conductor formed by mechanically and electrically connecting.

  The electrostatic chuck 1B has a smaller distance from the opening 8B to the bottom surface 9B of the recess 3B than the electrostatic chuck 1A. In other words, the thickness from the holding surface 12B that holds the semiconductor wafer when using the electrostatic chuck 1B to the bottom surface 9B of the recess 3B is larger in the electrostatic chuck 1B than in the electrostatic chuck 1A. .

  When the via connection conductor portion 14B is not provided, that is, in the case of the electrostatic chuck 1A, when the electrode terminal is brazed to the connection intermediate layer with the brazing material, the electrode terminal is connected in the middle. When the force of contact with the layer is increased, the base and the conductive layer may be deformed or cracked. On the other hand, in the electrostatic chuck 1B provided with the via connection conductor portion 14B, the thickness from the holding surface 12B to the bottom surface 9B of the recess 3B is increased, so that the electrode terminal 5B is brazed to the connection intermediate layer 6B. Even when the force with which the electrode terminal 5B comes into contact with the connection intermediate layer 6B is slightly increased when brazing with 11B, deformation or cracks are unlikely to occur in the base 2B and the conductive layer 4B, which is preferable.

  Here, a manufacturing method of the electrostatic chuck 1B will be described. The manufacturing method of the electrostatic chuck 1B is basically the same as the manufacturing method of the electrostatic chuck 1A described above, but in the following, the manufacturing method of the internal conductive layer 13B and the via connecting conductor portion 14B will be mainly described. To do.

  First, a green sheet is manufactured, and a green sheet laminate is obtained by laminating and pressing the green sheets cut into an appropriate size. Further, through holes for the recesses 3B and / or through holes for the via connecting conductor portions 14B are formed in some green sheet laminates by mechanical punching or drilling or the like.

  Next, for example, platinum powder, yttria powder containing calcium carbonate and the like and an appropriate organic vehicle are kneaded at an appropriate ratio to produce a conductive layer paste. This conductive layer paste can form not only the conductive layer 4B but also the internal conductive layer 13B and the via connecting conductor portion 14B. Note that the conductive layer paste for forming the conductive layer 4B, the internal conductive layer 13B, and the via connecting conductor portion 14B may have different ratios of materials to be kneaded or may be unified. The surface of the green sheet laminate is formed by screen printing so that the produced conductive layer paste is disposed in the internal conductive layer 13B close to the holding surface 12B, that is, the internal conductive layer 13B positioned above in FIG. Apply to. In addition, for the via connection conductor portion 14B, the surface of the green sheet laminate is masked with a resin film or the like, and the via hole for the via connection conductor portion 14B is filled with the conductive layer paste, whereby the via before firing is filled. The connecting conductor portion 14B can be formed.

  The connection intermediate layer 6B before firing can be obtained by coating the connection intermediate layer paste on the surface 10B of the conductive layer 4B, as in the electrostatic chuck 1A.

Next, while positioning the inner conductive layer 13B, the via connection conductor 14B, the conductive layer 4B, the connection intermediate layer 6B, and the recess 3B before firing, the green sheet laminate is placed under conditions of, for example, 70 ° C. and 50 kgf / cm ² . Laminate and crimp with. The steps of laminating and pressure-bonding the green sheet laminates are repeated until the desired thickness of the base body 2B before firing is formed, and formed into a desired shape such as a disk shape by end milling or the like. Thereby, the base body 2B, the concave portion 3B, the conductive layer 4B, the internal conductive layer 13B, and the via connecting conductor portion 14B before firing are obtained.

  The obtained base body 2B, concave portion 3B, conductive layer 4B, connection intermediate layer 6B, internal conductive layer 13B, and via connection conductor portion 14B before firing were fired under the same conditions as the electrostatic chuck 1A to obtain a sintered body. By performing the heat treatment for correcting the warp under the same conditions, the base body 2B, the concave portion 3B, the conductive layer 4B, the connection intermediate layer 6B, the internal conductive layer 13B, and the via connection conductor portion 14B can be obtained.

  Next, in a state where one end of the electrode terminal 5B is in contact with the recess 3B, the one end of the electrode terminal 5B and the recess 3B are brazed and joined with the brazing material 11B.

  Through the above steps, the electrostatic chuck 1B including the base body 2B, the recess 3B, the conductive layer 4B, the electrode terminal 5B, the connection intermediate layer 6B, the internal conductive layer 13B, and the via connection conductor portion 14B can be manufactured.

  As with the electrostatic chuck 1A, the obtained electrostatic chuck 1B can prevent the formation of cavities in the conductive layer 4B, the increase in resistance, the occurrence of electrical non-conduction, and the decrease in mechanical strength. It is possible to realize strong bonding between the electrode terminal 5B and the connection intermediate layer 6B. As a result, the electrostatic chuck 1B can be used for a long time, and the long-term reliability of the entire apparatus is improved.

  More specifically, the electrostatic chuck 1B is provided with the inner conductive layer 13B and the via connecting conductor portion 14B, and by increasing the thickness from the holding surface 12B to the bottom surface 9B of the recess 3B, the electrode terminal 5B and the connection intermediate layer are provided. When joining 6B, it becomes difficult to produce a deformation | transformation or a crack in the base | substrate 2B, the conductive layer 4B, etc. FIG. Therefore, moisture and the like enter from the cracks, and the base 2B and the conductive layer 4B do not deteriorate at an early stage, and further, the base 2B and the conductive layer 4B do not break from the deformed portion or the crack. Therefore, the electrostatic chuck 1B can further improve the durability against long-term use, and as a result, the long-term reliability of the entire apparatus is further improved.

  However, when the electrode terminal is bonded to the connection intermediate layer, the stress acting on the connection intermediate layer from the electrode terminal can be adjusted to such an extent that the base body and the conductive layer are not deformed or cracked. What is necessary is just to employ | adopt the aspect of 1 A of electrostatic chucks.

  Subsequently, the electrostatic chuck 1 </ b> C shown in FIG. 3 and the electrostatic chuck 1 </ b> A shown in FIG. 1 are different from each other in terms of the structure of the recess and the presence or absence of the secondary conductive layer. Except for this difference, since the electrostatic chuck 1A and the electrostatic chuck 1C use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 3, in the electrostatic chuck 1C, the recess 3C includes a large diameter portion 15C on the opening 8C side and a subsequent small diameter portion 16C, and the bottom surface 9C of the small diameter portion 16C that is the bottom surface of the recess 3C. The secondary conductive layer 19C formed to extend from the exposed surface 17C, which is the surface of the connection intermediate layer 6C formed on the surface 10C of the exposed conductive layer 4C, to the shelf 18C, which is the bottom surface of the large diameter portion 15C. The electrode terminal 5C is erected on the shelf portion 18C of the large-diameter portion 15C, and the secondary conductive layer 19C and the electrode terminal 5C are electrically connected.

  More specifically, a large-diameter portion 15C is formed from the opening 8C toward the holding surface 12C as the recess 3C in the electrostatic chuck 1C, and a large-diameter portion 15C from a part of the shelf portion 18C that is the bottom surface of the large-diameter portion 15C. A smaller-diameter portion 16C having a smaller diameter is formed toward the holding surface 12C. In other words, since the recess 3C has a step, there are two bottom surfaces. The bottom surface of the large-diameter portion 15C that is one bottom surface is the shelf portion 18C, and the bottom surface of the small-diameter portion 16C that is the bottom surface of the recess 3C that is the other bottom surface is the bottom surface 9C. The shelf portion 18C of the large-diameter portion 15C is formed in parallel with the holding surface 12C of the base 2C, but requires that the electrode terminal 5C is erected vertically with respect to the one main surface 7C and the holding surface 12C. If not, there is no limitation on the shape of the shelf portion 18C of the large diameter portion 15C. Further, the conductive layer 4C is exposed on the bottom surface 9C of the small diameter portion 16C, and the connection intermediate layer 6C is formed on the exposed surface 10C of the conductive layer 4C in the same manner as the electrostatic chuck 1A.

  Further, a secondary conductive layer 19C is formed on the exposed surface 17C exposed to the concave portion 3C side of the connection intermediate layer 6C. The secondary conductive layer 19C includes an exposed surface 17C of the connection intermediate layer 6C, an inner wall surface of the small diameter portion 16C, and a rising surface 20C that intersects the shelf portion 18C of the large diameter portion 15C, and the large diameter portion 15C. It is formed so as to be electrically continuous with the shelf 18C. Since the secondary conductive layer 19C is made of a conductive material, the electrical connection extends from the exposed surface 17C to the rising surface 20C and the shelf 18C. Further, the electrode terminal 5C is disposed upright by the brazing material 11C on the secondary conductive layer 19C formed on the shelf portion 18C of the large diameter portion 15C.

  The material of the secondary conductive layer 19C includes a conductive component such as a metal, and preferably includes a component that does not cause unintended alteration even at a brazing temperature of, for example, about 800 ° C. with a metal brazing material. Examples thereof include gold, silver, platinum, palladium, copper, nickel, molybdenum, manganese, and alloys thereof.

  In an aspect in which the concave portion 3C is divided into the large diameter portion 15C and the small diameter portion 16C as in the electrostatic chuck 1C, the electrode terminal 5C is disposed on the shelf portion 18C of the large diameter portion 15C. In the electrostatic chuck 1C, the distance from the opening 8C in the recess 3C to the shelf 18C of the large diameter portion 15C is smaller than the distance from the opening 8A to the bottom surface 9A of the electrostatic chuck 1A. In other words, the thickness from the holding surface 12C to the shelf portion 18C of the large-diameter portion 15C in the electrostatic chuck 1C is larger than the thickness from the holding surface 12A to the bottom surface 9A in the electrostatic chuck 1A.

  Here, a manufacturing method of the electrostatic chuck 1C will be described. The manufacturing method of the electrostatic chuck 1C is basically the same as the manufacturing method of the electrostatic chuck 1A described above. Hereinafter, the manufacturing method of the large diameter portion 15C, the small diameter portion 16C, and the secondary conductive layer 19C will be described. Mainly explained.

  First, a plurality of green sheets are prepared, cut into an appropriate size, and a plurality of green sheets having no through-holes are stacked and pressed to obtain a green sheet laminate. Further, through holes for the large diameter portion 15C and / or through holes for the small diameter portion 16C are formed in some green sheet laminates by mechanical punching or drilling.

  Next, similarly to the electrostatic chuck 1A, a conductive layer paste is prepared. The produced paste for conductive layer is applied to the surface of the green sheet laminate by screen printing so that the conductive layer 4C is arranged.

  The connection intermediate layer 6C before firing can be obtained by coating the connection intermediate layer paste on the surface 10C of the conductive layer 4C before firing, similarly to the electrostatic chuck 1A.

  Next, while positioning the conductive layer 4C before firing, the connecting intermediate layer 6C, the small diameter portion 16C and the large diameter portion 15C of the recess 3C, the green sheet laminates are laminated and pressure-bonded until the thickness of the base body 2C before firing is reached. Then, it is formed into a desired shape such as a disk shape by end milling or the like. Thereby, the base 2C before firing, the concave portion 3C having the large diameter portion 15C and the small diameter portion 16C, the conductive layer 4C, and the connection intermediate layer 6C are obtained.

  The obtained base 2C before firing, the recess 3C having the large diameter portion 15C and the small diameter portion 16C, the conductive layer 4C, and the connection intermediate layer 6C are fired under the same conditions as the electrostatic chuck 1A, and the warp of the sintered body is performed. By performing the heat treatment to be corrected under the same conditions, the base 2C, the concave portion 3C having the large diameter portion 15C and the small diameter portion 16C, the conductive layer 4C, and the connection intermediate layer 6C can be obtained.

  Further, the secondary conductive layer 19C is prepared, for example, by producing a paste for a secondary conductive layer in which silver powder and an appropriate organic vehicle are kneaded, and the exposed surface 17C, the rising surface 20C, and the large diameter portion of the connection intermediate layer 6C. After the secondary conductive layer paste is applied to the 15C shelf 18C, the applied secondary conductive layer paste is heat-treated at about 900 ° C., for example.

  Next, with one end portion of the electrode terminal 5C in contact with the shelf portion 18C of the large diameter portion 15C, the one end portion of the electrode terminal 5C and the shelf portion 18C of the large diameter portion 15C are brazed with the brazing material 11C. And join.

  Through the above steps, the electrostatic chuck 1C including the base 2C, the recess 3C, the conductive layer 4C, the electrode terminal 5C, the connection intermediate layer 6C, and the secondary conductive layer 19C can be manufactured.

  The obtained electrostatic chuck 1C, like the electrostatic chuck 1A and the electrostatic chuck 1B, prevents the formation of cavities in the conductive layer 4C, the increase in resistance, the occurrence of electrical discontinuity, and the reduction in mechanical strength. In addition, it is possible to realize strong bonding between the electrode terminal 5C and the connection intermediate layer 6C. As a result, the electrostatic chuck 1C can be used for a long time, and the long-term reliability of the entire apparatus is improved.

  Furthermore, the electrostatic chuck 1C is provided with a large diameter portion 15C and a small diameter portion 16C, and by increasing the thickness from the holding surface 12C to the shelf portion 18C of the large diameter portion 15C, the electrode terminal 5C and the shelf portion 18C. When the secondary conductive layer 19C formed on the substrate is joined, the base 2C, the conductive layer 4C, the connection intermediate layer 6C and the like are hardly deformed or cracked. Accordingly, moisture or the like enters from the cracks, and the base 2C, the conductive layer 4C, the connection intermediate layer 6C, and the like do not deteriorate early, and the base 2C, the conductive layer 4C, and the connection intermediate start from the deformed portion or the crack. The layer 6C or the like is not broken. Therefore, the electrostatic chuck 1C can further improve the durability against long-term use, and as a result, the long-term reliability of the entire apparatus is further improved.

  However, when the electrode terminal 5C is joined to the secondary conductive layer 19C, the stress acting on the secondary conductive layer 19C from the electrode terminal 5C is deformed or cracked in the base 2C, the conductive layer 4C, and the connection intermediate layer 6C. If it can be adjusted to such an extent that it does not occur, the aspect of the electrostatic chuck 1A may be adopted.

  Next, the electrostatic chuck 1D shown in FIG. 4 is a modification of the electrostatic chuck 1C shown in FIG. The differences between the electrostatic chuck 1D and the electrostatic chuck 1C are the locations where the electrode terminals are joined and the presence or absence of a brazing material. Except for this difference, since the electrostatic chuck 1D and the electrostatic chuck 1C use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 4, in the electrostatic chuck 1D, the electrode terminal 5D is joined not to the surface of the secondary conductive layer 19D of the large diameter portion 15D but to the shelf portion 18D of the large diameter portion 15D. The joining mode of the electrode terminal 5D is a mode in which one end of the electrode terminal 5D is not brazed but the secondary conductive layer 19D surrounds and cures the peripheral side surface of the one end of the electrode terminal 5D. . As a material of the secondary conductive layer 19D, it is preferable that the material includes a conductive component such as a metal and can be firmly bonded to both the electrode terminal 5D and the shelf 18D. For example, silver, The thermosetting resin adhesive containing metal particles, such as copper and nickel, can be mentioned.

  Since the secondary conductive layer 19D is electrically connected to the conductive layer 4D and the connection intermediate layer 6D in the same manner as the electrostatic chuck 1C, the secondary conductive layer 19D directly holding the electrode terminal 5D and the electrode terminal 5D Is electrically connected.

  The manufacturing method of the electrostatic chuck 1D is basically the same as that of the electrostatic chuck 1C. In the following, a method for forming the secondary conductive layer 19D and a method for joining the electrode terminals 5D will be mainly described.

  First, a plurality of green sheets are prepared, cut into an appropriate size, and a plurality of green sheets having no through-holes are stacked and pressed to obtain a green sheet laminate. Furthermore, through holes for the large diameter portion 15DC and / or through holes for the small diameter portion 16D are formed in some green sheet laminates by mechanical punching or drilling or the like.

  Next, similarly to the electrostatic chuck 1A, a conductive layer paste is prepared. The produced paste for conductive layer is applied to the surface of the green sheet laminate by screen printing so that the conductive layer 4D is arranged.

  The connection intermediate layer 6D before firing can be obtained by coating the connection intermediate layer paste on the surface 10D of the conductive layer 4D before firing, similarly to the electrostatic chuck 1A.

  Next, while positioning the conductive layer 4D before firing, the connection intermediate layer 6D, and the small diameter portion 16D and the large diameter portion 15D of the recess 3D, the green sheet laminates are laminated and pressed until the thickness of the base 2D before firing is reached. Then, it is formed into a desired shape such as a disk shape by end milling or the like. Thereby, the base 2D before firing, the recess 3D having the large diameter portion 15D and the small diameter portion 16D, the conductive layer 4D, and the connection intermediate layer 6D are obtained.

  The obtained base 2D before firing, the recess 3D having the large diameter portion 15D and the small diameter portion 16D, the conductive layer 4D, and the connection intermediate layer 6D are fired under the same conditions as the electrostatic chuck 1A, and the warp of the sintered body is performed. By performing the heat treatment to be corrected under the same conditions, the base 2D, the concave portion 3D having the large diameter portion 15D and the small diameter portion 16D, the conductive layer 4D, and the connection intermediate layer 6D can be obtained.

  Further, a secondary conductive layer paste is prepared, and the electrode terminals 5D are arranged upright on the shelf portion 18D of the large diameter portion 15D, while the exposed surface 17D, the rising surface 20D, and the large diameter portion 15D of the connection intermediate layer 6D. After the secondary conductive layer paste is applied to the shelf 18D, the applied secondary conductive layer paste is thermally cured by, for example, heat treatment at about 200 ° C. The formation of the conductive layer 19D is achieved at the same time. The electrode terminal 5D is disposed so as to be in contact with the shelf 18D after the secondary conductive layer paste is applied to the exposed surface 17D, the rising surface 20D, and the shelf 18D, and then for the secondary conductive layer. The paste may be cured.

  Through the above steps, the base 2D, the concave portion 3D having the large diameter portion 15D and the small diameter portion 16D, the conductive layer 4D, the electrode terminal 5D joined to the shelf portion 18D of the large diameter portion 15D, the connection intermediate layer 6D, and the secondary conductive material. An electrostatic chuck 1D including the layer 19D can be manufactured.

  As with the electrostatic chucks 1A to 1C, the obtained electrostatic chuck 1D can prevent the formation of cavities in the conductive layer 4D, the increase in resistance, the occurrence of electrical discontinuity, and the reduction in mechanical strength. At the same time, it is possible to realize strong bonding between the electrode terminal 5D and the connection intermediate layer 6D. As a result, the electrostatic chuck 1D can be used for a long period of time, and the long-term reliability of the entire apparatus is improved.

  Further, the electrostatic chuck 1D is provided with a large diameter portion 15D and a small diameter portion 16D in the same manner as the electrostatic chuck 1C, and by increasing the thickness from the holding surface 12D to the shelf portion 18D of the large diameter portion 15D. When the electrode terminal 5D and the shelf portion 18D are joined, the base 2D, the conductive layer 4D, the connection intermediate layer 6D, and the like are hardly deformed or cracked. Therefore, moisture or the like enters from the cracks, and the base 2D, the conductive layer 4D, and the connection intermediate layer 6D do not deteriorate at an early stage. Further, the base 2D, the conductive layer 4D, and the connection intermediate are started from the deformed portion or the crack. The layer 6D or the like is not broken. Therefore, the electrostatic chuck 1D can further improve the durability against long-term use, and as a result, the long-term reliability of the entire apparatus is further improved.

  Further, in the electrostatic chuck 1D, the secondary conductive layer 19D itself is a joining means for the electrode terminal 5D, and the electrode terminal 5D is not joined to the surface of the secondary conductive layer 19D. Since 5D peeling does not occur, the bonding strength of the electrode terminal 5D is further improved as compared with, for example, the electrostatic chuck 1C. As a result, the electrostatic chuck 1D is further improved in durability against long-term use, and the long-term reliability of the entire apparatus is improved.

  Next, the electrostatic chuck 1E shown in FIG. 5 is a modification of the electrostatic chuck 1C shown in FIG. The difference between the electrostatic chuck 1E and the electrostatic chuck 1C is the presence or absence of an internal conductive layer and a via connecting conductor. Except for this difference, since the electrostatic chuck 1E and the electrostatic chuck 1C use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 5, the electrostatic chuck 1E includes an internal conductive layer 13E and a via connecting conductor portion 14E. The internal conductive layer 13E and the via connection conductor 14E are members similar to the internal conductive layer 13B and the via connection conductor 14B in the electrostatic chuck 1B, and are conductive members. Furthermore, since the secondary conductive layer 19E is electrically connected to the connection intermediate layer 6E, the electrostatic chuck 1E includes the internal conductive layer 13E, the via connection conductor portion 14E, the conductive layer 4E, and the connection intermediate layer. 6E, secondary conductive layer 19E, and electrode terminal 5E are electrically connected.

  As a manufacturing method of the electrostatic chuck 1E, the formation method of the internal conductive layer 13E and the via connection conductor portion 14E is the same as the formation method of the internal conductive layer 13B and the via connection conductor portion 14B of the electrostatic chuck 1B. Detailed description is omitted. In addition, other methods for producing the recess 3E, the conductive layer 4E, the connection intermediate layer 6E, and the secondary conductive layer 19E and the method for joining the electrode terminal 5E are the recess 3C, the conductive layer 4C, and the connection intermediate of the electrostatic chuck 1C. Since the manufacturing method of the layer 6C and the secondary conductive layer 19C and the bonding method of the electrode terminal 5C are the same, detailed description is omitted.

  As with the electrostatic chucks 1A to 1D, the obtained electrostatic chuck 1E can prevent the formation of voids in the conductive layer 4E, the increase in resistance, the occurrence of electrical discontinuity, and the reduction in mechanical strength. At the same time, it is possible to realize strong bonding between the electrode terminal 5E and the connection intermediate layer 6E. As a result, the electrostatic chuck 1E can be used for a long time, and the long-term reliability of the entire apparatus is improved.

  Furthermore, the electrostatic chuck 1E is provided with a large diameter portion 15E and a small diameter portion 16E, an internal conductive layer 13E and a via connection conductor portion 14E, and the thickness from the holding surface 12E to the shelf portion 18E of the large diameter portion 15E. When the electrode terminal 5E and the shelf 18E are joined, the base 2E, the conductive layer 4E, the connection intermediate layer 6E, the via connection conductor 14E, the internal conductive layer 13E, etc. are deformed or cracked. Not likely to occur. Therefore, moisture or the like enters from the cracks, and the base 2E, the conductive layer 4E, the connection intermediate layer 6E, the via connection conductor portion 14E, the internal conductive layer 13E, and the like are not deteriorated at an early stage. As a starting point, the base 2E, the conductive layer 4E, the connection intermediate layer 6E, the via connection conductor 14E, the internal conductive layer 13E, and the like are not broken. Therefore, the electrostatic chuck 1E can further improve the durability against long-term use, and as a result, the long-term reliability of the entire apparatus is further improved.

  Next, the electrostatic chuck 1F shown in FIG. 6 is a modification of the electrostatic chuck 1E shown in FIG. The difference between the electrostatic chuck 1F and the electrostatic chuck 1E is the joining location of the electrode terminals and the presence or absence of a brazing material. Except for this difference, since the electrostatic chuck 1F and the electrostatic chuck 1E use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 6, in the electrostatic chuck 1F, the electrode terminal 5F is joined to the shelf 18F of the large diameter portion 15F, not the surface of the secondary conductive layer 19F of the large diameter portion 15F. The joining mode of the electrode terminal 5F is a mode in which one end of the electrode terminal 5F is not brazed but the secondary conductive layer 19F surrounds and cures the peripheral side surface of the one end of the electrode terminal 5F. . That is, the joining mode of the electrode terminals 5F in the electrostatic chuck 1F is the same as the joining mode of the electrode terminals 5D in the electrostatic chuck 1D shown in FIG.

  As a manufacturing method of the electrostatic chuck 1F, the formation method of the internal conductive layer 13F and the via connection conductor portion 14F is the same as the formation method of the internal conductive layer 13B and the via connection conductor portion 14B of the electrostatic chuck 1B. Detailed description is omitted. In addition, other methods for producing the recess 3F, the conductive layer 4F, the connection intermediate layer 6F, and the secondary conductive layer 19F, and the method for joining the electrode terminals 5F are the recess 3D, the conductive layer 4D, and the connection intermediate of the electrostatic chuck 1D. Since it is the same as the manufacturing method of the layer 6D and the secondary conductive layer 19D and the bonding method of the electrode terminal 5D, detailed description is omitted.

  As with the electrostatic chucks 1A to 1E, the obtained electrostatic chuck 1F can prevent the formation of voids in the conductive layer 4F, the increase in resistance, the occurrence of electrical discontinuity, and the reduction in mechanical strength. At the same time, it is possible to realize strong bonding between the electrode terminal 5F and the connection intermediate layer 6F. As a result, the electrostatic chuck 1F can be used for a long time, and the long-term reliability of the entire apparatus is improved.

  Furthermore, the electrostatic chuck 1F is provided with a large-diameter portion 15F and a small-diameter portion 16F, an internal conductive layer 13F and a via-connecting conductor portion 14F, and has a thickness from the holding surface 12F to the shelf portion 18F of the large-diameter portion 15F. When the electrode terminal 5F and the shelf portion 18F are joined together, the base 2F, the conductive layer 4F, the connection intermediate layer 6F, the via connection conductor portion 14F, the internal conductive layer 13F, etc. are deformed or cracked. Not likely to occur. Accordingly, moisture or the like enters from the cracks, and the base 2F, the conductive layer 4F, the connection intermediate layer 6F, the via connection conductor portion 14F, the internal conductive layer 13F, and the like are not deteriorated at an early stage. As a starting point, the base 2F, the conductive layer 4F, the connection intermediate layer 6F, the via connection conductor portion 14F, the internal conductive layer 13F, and the like are not broken. Therefore, the electrostatic chuck 1F can further improve the durability against long-term use, and as a result, the long-term reliability of the entire apparatus is further improved.

  In the electrostatic chuck 1F, the secondary conductive layer 19F itself is a joining means for the electrode terminal 5F, and the electrode terminal 5F is not joined to the surface of the secondary conductive layer 19F. Since peeling of 5F does not occur, the bonding strength of the electrode terminal 5F is further improved as compared with, for example, the electrostatic chuck 1E. As a result, the electrostatic chuck 1F is further improved in durability against long-term use, and the long-term reliability of the entire apparatus is improved.

  The difference between the electrostatic chuck 1G shown in FIG. 7 and the electrostatic chuck 1C shown in FIG. 3 is the mode of the bottom in the large diameter portion and the mode of joining the electrode terminals. Except for this difference, since the electrostatic chuck 1G and the electrostatic chuck 1C use substantially the same members, detailed description may be omitted.

  The electrostatic chuck 1G shown in FIG. 7 has a concave portion 3G composed of a large diameter portion 15G on the opening 8G side of the concave portion 3G and a subsequent small diameter portion 16G, and is exposed to the bottom surface 9G of the concave portion 3G of the small diameter portion 16G. A small-diameter-side connection intermediate layer 21G formed on the surface of 4G and a large-diameter-side connection intermediate formed on the surface of the conductive layer 22G formed exposed to the shelf 18G of the large-diameter portion 16G of the same recess 3G A large-diameter-side connection intermediate layer, including a layer 23G, and a secondary conductive layer 19G that electrically connects both the surface of the small-diameter-side connection intermediate layer 21G and the surface of the large-diameter-side connection intermediate layer 23G. The secondary conductive layer 19G formed on the surface of 23G or the large-diameter portion side connection intermediate layer 23G and the electrode terminal 5G are electrically connected.

  In the electrostatic chuck 1G, the aspect in which the concave portion is divided into the large diameter portion and the small diameter portion is the same as that of the electrostatic chucks 1C to 1F. Further, the small diameter portion side connection intermediate layer 21G formed on the surface 10G of the conductive layer 4G exposed on the bottom surface 9G of the recess 3G of the electrostatic chuck 1G is connected to the connection intermediate layers 6A to 6A of the electrostatic chucks 1A to 1F. It is the same as 6F.

  The shelf 18G in the recess 3G is formed with a conductive layer 22G containing the same components as the conductive layer 4G formed in the base 2G, for example, platinum and a ceramic mainly composed of yttria. Further, similarly to the conductive layer 4G, the surface of the conductive layer 22G is covered with a large-diameter side connection intermediate layer 23G that is one of the connection intermediate layers 6G. That is, in the electrostatic chuck 1G, the conductive layer and the connection intermediate layer are respectively formed on the bottom surface 9G of the small diameter portion 16G of the recess 3G and the shelf portion 18G of the large diameter portion 15G.

  A secondary conductive layer 19G similar to the electrostatic chucks 1C to 1F is formed between the small-diameter portion side connection intermediate layer 21G and the large-diameter portion side connection intermediate layer 23G. In addition, as an aspect of the secondary conductive layer 19G, as shown on the left side of FIG. 7, the secondary conductive layer 19G is formed so as to be in contact with a part of the large-diameter portion side connection intermediate layer 23G. 7, the secondary conductive layer 19 </ b> G may be formed so as to cover the surface of the large-diameter portion side connection intermediate layer 23 </ b> G.

  The electrode terminal 5G is joined to the large-diameter portion side connection intermediate layer 23G in the embodiment shown on the left side of FIG. 7, and the large-diameter portion side connection intermediate layer 23G is connected to the large-diameter portion connection intermediate layer 23G in the embodiment shown on the right side of FIG. It is joined to the covering secondary conductive layer 19G. In either embodiment, the electrode terminal 5G is brazed with the brazing material 11G.

  The conductive layer 4G, the small-diameter portion side connection intermediate layer 21G, the secondary conductive layer 19G, the conductive layer 22G, the large-diameter portion side connection intermediate layer 23G, and the electrode terminal 5G are all conductors and are mechanically connected. So it is electrically conductive.

  As a manufacturing method of the electrostatic chuck 1G, a method of forming the recess 3G, the conductive layer 4G, and the small diameter side connection intermediate layer 21G is a method of forming the recess 3C, the conductive layer 4C, and the connection intermediate layer 6C of the electrostatic chuck 1C. Since it is the same, detailed description is abbreviate | omitted.

  The conductive layer 22G formed on the shelf portion 18G of the large-diameter portion 15G can be formed by coating and baking by a screen printing method or the like, for example, similarly to the conductive layer 4A of the electrostatic chuck 1A. Further, the large-diameter portion side connection intermediate layer 23G can be formed, for example, by applying a connection intermediate layer paste on the surface of the conductive layer 22G and baking, like the connection intermediate layer 6A of the electrostatic chuck 1A. it can. Further, as a method for joining the electrode terminal 5G, in the aspect in which the electrode terminal 5G is joined to the large-diameter portion side connection intermediate layer 23G shown on the left side of FIG. 7, the joining method of the electrode terminal 5A of the electrostatic chuck 1A is adopted. In the embodiment in which the electrode terminal 5G is bonded to the secondary conductive layer 19G shown on the right side of FIG. 7, a method of bonding the electrode terminal 5C of the electrostatic chuck 1C can be employed.

  As with the electrostatic chucks 1C to 1F, the obtained electrostatic chuck 1G has a thickness from the holding surface 12G to the shelf portion 18G of the large diameter portion 15G from the holding surface 12A to the bottom surface 9A in the electrostatic chuck 1A. Larger than thickness. Therefore, when the electrode terminal 5G is joined to the large-diameter portion side connection intermediate layer 23G or the secondary conductive layer 19G formed on the surface of the large-diameter portion side connection intermediate layer 23G, the base 2G, the conductive layer 4G, In addition, deformation or cracks are less likely to occur in the small diameter portion side connection intermediate layer 21G and the like, which is preferable.

  In the electrostatic chuck 1G, when the electrode terminal 5G is bonded to the large-diameter portion side connection intermediate layer 23G or the secondary conductive layer 19G formed on the surface of the large-diameter portion side connection intermediate layer 23G, the substrate 2G The conductive layer 4G, the small-diameter portion side connection intermediate layer 21G, and the like are not easily deformed or cracked. Accordingly, moisture or the like enters from the cracks, and the base 2G, the conductive layer 4G, the small-diameter portion side connection intermediate layer 21G, and the like do not deteriorate early, and the base 2G, the conductive layer 4G, And the small diameter part side connection intermediate layer 21G and the like are not broken. Therefore, by providing the large diameter portion 15G and the small diameter portion 16G and increasing the thickness from the holding surface 12G to the shelf portion 18G of the large diameter portion 15G, the electrostatic chuck 1G can obtain durability against long-term use. As a result, the long-term reliability of the entire apparatus is improved.

  Furthermore, since the electrode terminal 5G is not joined to the shelf portion 18G of the large-diameter portion 15G, the electrostatic chuck 1G is connected from the electrode terminal 5G to the base 2G when the electrode terminal 5G is joined and when the electrostatic chuck 1G is used. Since the acting stress can be further reduced as compared with the electrostatic chucks 1C to 1F, the long-term reliability of the entire apparatus can be further improved.

  Next, the electrostatic chuck 1H shown in FIG. 8 is a modification of the electrostatic chuck 1G shown in FIG. The difference between the electrostatic chuck 1H and the electrostatic chuck 1G is the presence or absence of a brazing material. Except for this difference, since the electrostatic chuck 1H and the electrostatic chuck 1G use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 8, the electrostatic chuck 1H has a large-diameter portion side in which the electrode terminal 5H is formed not on the surface of the secondary conductive layer 19H of the large-diameter portion 15H but on the shelf portion 18H of the large-diameter portion 15H. It is joined to the connection intermediate layer 23H. The joining mode of the electrode terminal 5H is a mode in which one end portion of the electrode terminal 5H is not brazed but the secondary conductive layer 19H surrounds and cures the peripheral side surface of the one end portion of the electrode terminal 5H. . That is, the means for joining the electrode terminal 5H in the electrostatic chuck 1H includes the means for joining the electrode terminal 5D in the electrostatic chuck 1D shown in FIG. 4 and the means for joining the electrode terminal 5F in the electrostatic chuck 1F shown in FIG. It is the same.

  As a manufacturing method of the electrostatic chuck 1H, the manufacturing method of the recess 3H, the conductive layer 4H, and the connection intermediate layer 6H is the same as the manufacturing method of the recess 3G, the conductive layer 4G, and the connection intermediate layer 6G of the electrostatic chuck 1G. Therefore, detailed description is omitted. Further, the bonding method of the electrode terminal 5H is the same as the bonding method of the electrode terminal 5D of the electrostatic chuck 1D and the bonding method of the electrode terminal 5F of the electrostatic chuck 1F, and thus detailed description thereof is omitted.

  As with the electrostatic chucks 1A to 1G, the obtained electrostatic chuck 1H can prevent the formation of cavities in the conductive layer 4H, the increase in resistance, the occurrence of electrical discontinuity, and the reduction in mechanical strength. At the same time, it is possible to realize strong bonding between the electrode terminal 5H and the connection intermediate layer 6H. As a result, the electrostatic chuck 1H can be used for a long time, and the long-term reliability of the entire apparatus is improved.

  More specifically, the electrostatic chuck 1H is provided with a large diameter portion 15H and a small diameter portion 16H, and the electrode terminal 5H is connected to the large diameter portion by increasing the thickness from the holding surface 12H to the shelf portion 18H of the large diameter portion 15H. When bonded to the side connection intermediate layer 23H, the base 2H, the conductive layer 4H, the connection intermediate layer 6H, and the like are unlikely to be deformed or cracked. Accordingly, moisture or the like enters from the cracks, and the base 2H, the conductive layer 4H, the connection intermediate layer 6H, and the like are not deteriorated at an early stage, and the base 2H, the conductive layer 4H, and the connection intermediate are started from the deformed portion or the crack. The layer 6H or the like is not broken. Therefore, the electrostatic chuck 1H can further improve the durability against long-term use, and as a result, the long-term reliability of the entire apparatus is further improved.

  Further, in the electrostatic chuck 1H, the secondary conductive layer 19H itself is a joining means for the electrode terminal 5H, and the electrode terminal 5H is not joined to the surface of the secondary conductive layer 19H, whereby the electrode terminal from the secondary conductive layer 19H is obtained. Since peeling of 5H does not occur, the bonding strength of the electrode terminal 5H is further improved as compared with, for example, the electrostatic chuck 1G. As a result, the electrostatic chuck 1H is further improved in durability against long-term use, and the long-term reliability of the entire apparatus is improved.

  Furthermore, since the electrode terminal 5H is not joined to the shelf portion 18H of the large-diameter portion 15H, the electrostatic chuck 1H is connected from the electrode terminal 5H to the base 2H when the electrode terminal 5H is joined and when the electrostatic chuck 1H is used. Since the acting stress can be further reduced as compared with the electrostatic chucks 1C to 1F, the long-term reliability of the entire apparatus can be further improved.

  Subsequently, the electrostatic chuck 1J shown in FIG. 9 is a modification of the electrostatic chuck 1G shown in FIG. The difference between the electrostatic chuck 1J and the electrostatic chuck 1G is the presence or absence of an internal conductive layer and a via connecting conductor. Except for this difference, since the electrostatic chuck 1J and the electrostatic chuck 1G use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 9, the electrostatic chuck 1J includes an internal conductive layer 13J and a via connecting conductor portion 14J. The internal conductive layer 13J and the via connection conductor 14J are members similar to the internal conductive layer 13B and the via connection conductor 14B in the electrostatic chuck 1B, and are conductive members. Further, since the secondary conductive layer 19J is electrically connected to the connection intermediate layer 6J, the electrostatic chuck 1J includes an internal conductive layer 13J, a via connection conductor portion 14J, a conductive layer 4J, and a small diameter portion side. The connection intermediate layer 21J, the secondary conductive layer 19J, the conductive layer 22J, the large diameter side connection intermediate layer 23J, and the electrode terminal 5J are electrically connected.

  As an aspect of the secondary conductive layer 19J, as in the electrostatic chuck 1G, as shown on the left side of FIG. 9, the secondary conductive layer 19J is in contact with a part of the large-diameter side connection intermediate layer 23J. An embodiment in which the secondary conductive layer 19J is formed so as to cover the surface of the large-diameter portion side connecting intermediate layer 23J as shown on the right side of FIG. 9 can be given.

  Similarly to the electrostatic chuck 1G, the electrode terminal 5J is bonded to the large-diameter portion side connection intermediate layer 23J in the mode shown on the left side of FIG. 9, and in the mode shown on the right side of FIG. It is joined to the secondary conductive layer 19J covering the large-diameter portion side connection intermediate layer 23J. In either embodiment, the electrode terminal 5J is brazed with the brazing material 11J.

  As a manufacturing method of the electrostatic chuck 1J, the formation method of the internal conductive layer 13J and the via connection conductor portion 14J is the same as the formation method of the internal conductive layer 13B and the via connection conductor portion 14B of the electrostatic chuck 1B. Detailed description is omitted. In addition, the other recesses 3J, the conductive layer 4J, the small-diameter portion side connection intermediate layer 21J, and the secondary conductive layer 19J are manufactured by the method of forming the recess 3C, the conductive layer 4C, the connection intermediate layer 6C, and the secondary conductive layer 19J of the electrostatic chuck 1C. Since it is the same as the manufacturing method of the conductive layer 19C, detailed description is abbreviate | omitted. Furthermore, the method for forming the conductive layer 22J and the large diameter portion side connection intermediate layer 23J is the same as the method for forming the conductive layer 22G and the large diameter portion side connection intermediate layer 23G of the electrostatic chuck 1G, and thus detailed description thereof is omitted. To do.

  As with the electrostatic chucks 1C to 1F, the obtained electrostatic chuck 1J has a thickness from the holding surface 12J to the shelf portion 18J of the large diameter portion 15J from the holding surface 12A to the bottom surface 9A of the electrostatic chuck 1A. Larger than thickness. Therefore, when the electrode terminal 5J is joined to the large-diameter portion side connection intermediate layer 23J or the secondary conductive layer 19J formed on the surface of the large-diameter portion side connection intermediate layer 23J, the base 2J, the conductive layer 4J, This is preferable because deformation or cracks are less likely to occur in the small-diameter portion side connection intermediate layer 21J, the internal conductive layer 13J, the via connection conductor portion 14J, and the like.

  In the electrostatic chuck 1J, when the electrode terminal 5J is joined to the large-diameter portion side connecting intermediate layer 23J or the secondary conductive layer 19J formed on the surface of the large-diameter portion side connecting intermediate layer 23J, the base 2J, the conductive layer 4J, the small-diameter portion side connection intermediate layer 21J, the internal conductive layer 13J, and the via connection conductor portion 14J are hardly deformed or cracked. Accordingly, moisture or the like enters from the cracks, and the base 2J, the conductive layer 4J, the small diameter side connection intermediate layer 21J, the internal conductive layer 13J, the via connection conductor 14J, and the like are not deteriorated at an early stage. Alternatively, the base 2J, the conductive layer 4J, the small-diameter-side connection intermediate layer 21J, the internal conductive layer 13J, the via-connecting conductor portion 14J, and the like are not broken starting from the crack. Therefore, by providing the large diameter portion 15J and the small diameter portion 16J, the internal conductive layer 13J and the via connection conductor portion 14J, and increasing the thickness from the holding surface 12J to the shelf portion 18J of the large diameter portion 15J, The electric chuck 1J obtains durability against long-term use, and as a result, the long-term reliability of the entire apparatus is improved.

  Further, since the electrode terminal 5J is not joined to the shelf portion 18J of the large diameter portion 15J, the electrostatic chuck 1J is connected from the electrode terminal 5J to the base 2J when the electrode terminal 5J is joined and when the electrostatic chuck 1J is used. Since the acting stress can be further reduced as compared with the electrostatic chucks 1C to 1F, the long-term reliability of the entire apparatus can be further improved.

  Next, the electrostatic chuck 1K shown in FIG. 10 is a modification of the electrostatic chuck 1J shown in FIG. The difference between the electrostatic chuck 1K and the electrostatic chuck 1J is the presence or absence of a brazing material. Except for this difference, since the electrostatic chuck 1K and the electrostatic chuck 1J use substantially the same members, detailed description of the common members may be omitted.

  As shown in FIG. 10, the electrostatic chuck 1K has a large-diameter portion side in which the electrode terminal 5K is formed not on the surface of the secondary conductive layer 19K of the large-diameter portion 15K but on the shelf portion 18K of the large-diameter portion 15K. It is joined to the connection intermediate layer 23K. The joining mode of the electrode terminal 5K is a mode in which one end portion of the electrode terminal 5K is not brazed but the secondary conductive layer 19K surrounds and cures the peripheral side surface of the one end portion of the electrode terminal 5K. . That is, the means for joining the electrode terminals 5K in the electrostatic chuck 1K are the means for joining the electrode terminals 5D in the electrostatic chuck 1D shown in FIG. 4, the means for joining the electrode terminals 5F in the electrostatic chuck 1F shown in FIG. This is the same as the joining means for the electrode terminal 5H in the electrostatic chuck 1H shown in FIG.

  As a manufacturing method of the electrostatic chuck 1K, the manufacturing method of the recess 3K, the conductive layer 4K, and the connection intermediate layer 6K is the same as the manufacturing method of the recess 3J, the conductive layer 4J, and the connection intermediate layer 6J of the electrostatic chuck 1J. Therefore, detailed description is omitted. The method for joining the electrode terminals 5K is the same as the method for joining the electrode terminals 5D of the electrostatic chuck 1D, the method of joining the electrode terminals 5F of the electrostatic chuck 1F, and the method of joining the electrode terminals 5H of the electrostatic chuck 1H. Therefore, detailed description is omitted.

  As with the electrostatic chucks 1A to 1J, the obtained electrostatic chuck 1K can prevent the formation of cavities in the conductive layer 4K, the increase in resistance, the occurrence of electrical discontinuity, and the reduction in mechanical strength. At the same time, it is possible to realize strong bonding between the electrode terminal 5K and the connection intermediate layer 6K. As a result, the electrostatic chuck 1K can be used for a long period of time, and the long-term reliability of the entire apparatus is improved.

  Furthermore, the electrostatic chuck 1K is provided with a large diameter portion 15K and a small diameter portion 16K, an internal conductive layer 13K and a via connecting conductor portion 14K, and has a thickness from the holding surface 12K to the shelf portion 18K of the large diameter portion 15K. When the electrode terminal 5K is joined to the large-diameter portion side connection intermediate layer 23K, the base 2K, the conductive layer 4K, the small-diameter portion side connection intermediate layer 21K, the internal conductive layer 13K, and the via connection conductor portion are increased. Deformation or cracks hardly occur at 14K. Accordingly, moisture or the like enters from the cracks, and the base 2K, the conductive layer 4K, the small diameter side connection intermediate layer 21K, the internal conductive layer 13K, the via connection conductor 14K, and the like are not deteriorated at an early stage. Alternatively, the base 2K, the conductive layer 4K, the small-diameter side connection intermediate layer 21K, the internal conductive layer 13K, the via connection conductor portion 14K, and the like are not broken starting from the crack. Therefore, the electrostatic chuck 1K can further improve the durability against long-term use, and as a result, the long-term reliability of the entire apparatus is further improved.

  Further, in the electrostatic chuck 1K, the secondary conductive layer 19K itself is a joining means for the electrode terminal 5K. By not joining the electrode terminal 5K to the surface of the secondary conductive layer 19K, the electrode terminal from the secondary conductive layer 19K. Since 5K peeling does not occur, the bonding strength of the electrode terminal 5K is further improved as compared with, for example, the electrostatic chuck 1J. As a result, the electrostatic chuck 1K is further improved in durability against long-term use, and the long-term reliability of the entire apparatus is improved.

  Further, since the electrode terminal 5K is not joined to the shelf portion 18K of the large diameter portion 15K, the electrostatic chuck 1K is connected to the base 2K from the electrode terminal 5K when the electrode terminal 5K is joined and when the electrostatic chuck 1K is used. As a result, the long-term reliability of the entire apparatus can be further improved.

  An electrostatic chuck 1L shown in FIG. 11 is a modification of the electrostatic chuck 1B shown in FIG. The difference between the electrostatic chuck 1L and the electrostatic chuck 1B is the mode of the connection intermediate layer. Except for this difference, since the electrostatic chuck 1L and the electrostatic chuck 1B use substantially the same members, detailed description may be omitted.

  In the electrostatic chuck 1L, the end 24L of the connection intermediate layer 6L formed on the surface 10L of the conductive layer 4L formed exposed to the bottom surface 9L of the recess 3L is separated from the inner wall surface 25L of the recess 3L. Yes.

  As a method for isolating the end 24L of the connection intermediate layer 6L from the inner wall surface 25L of the recess 3L, for example, a conductive layer 4L smaller than the conductive layer 4B and the connection intermediate layer 6B of the electrostatic chuck 1B and the connection intermediate The layer 6L is formed and the size of the recesses is the same, or the recess 3L having a diameter larger than that of the recess 3B of the electrostatic chuck 1B is formed, and the conductive layer and the connection intermediate layer have the same size. And the like.

  The electrostatic chuck 1L not only achieves the object of the present invention that can be achieved by the electrostatic chuck 1B, but can more reliably suppress cracks that may occur in the base 2L. More specifically, the electrostatic chuck 1L has the end portions of the conductive layer 4L and the connection intermediate layer 6L that are not in close contact with the inner wall surface 25L of the recess 3L and does not bite into the base 2L. No stress is concentrated on the close contact portion and the biting portion at the time of firing in the course of manufacturing or when brazing the brazing material 11L. Therefore, if the generation of stress is suppressed during firing and brazing, the generation of cracks can be more reliably suppressed.

  Hereinafter, experimental examples using embodiments of the electrostatic chuck according to the present invention will be described.

Example 1
Example 1 is an example in which the electrostatic chuck of the embodiment shown in FIG. 11 is manufactured.
First, a predetermined amount of yttria powder, calcium carbonate powder as an auxiliary, a binder, a dispersant, and a solvent were mixed to prepare a slurry. By using this slurry, a yttria green sheet having a thickness of 0.2 mm was obtained by a doctor blade method.
Next, 4 to 10 green sheets cut to 450 mm square were laminated and pressure-bonded under the conditions of 70 ° C. and 50 kgf / cm ² to obtain green sheet laminates of several thicknesses.
Further, through holes for via connecting conductors or through holes for recesses were drilled in the green sheet laminate by mechanical punching or drilling. The through-hole for a recess was drilled to a size such that the diameter after firing was 6 mm.
A conductive layer paste was prepared by kneading 50 parts by volume of yttria powder containing calcium carbonate as an auxiliary agent, 50 parts by volume of platinum powder, and an organic vehicle. In addition, a via connection conductor part paste was prepared by kneading 30 parts by volume of yttria powder containing calcium carbonate as an auxiliary agent, 70 parts by volume of platinum powder, and an organic vehicle.
The surface of the green sheet laminate other than the through hole for the via connection conductor was masked with a resin film, and the via connection conductor part paste was filled into the through hole for the via connection conductor with a rubber squeegee. In addition, the conductive layer paste was applied to the surface of the green sheet laminate, part of which became the holding surface 12L, so as to be the internal conductive layer 13L. Furthermore, the conductive layer paste was applied to the surface of another green sheet laminate so as to be the conductive layer 4L. In addition, the outer periphery of the conductive layer 4L was coated so that the diameter after firing was 4 mm.
Platinum powder and an organic vehicle were kneaded to prepare a 100% platinum connecting intermediate layer paste. The connection intermediate layer paste was applied so as to cover the conductive layer 4L and to have a diameter after firing of 5 mm.
The green sheet laminate in which the conductive layer 4L, the internal conductive layer 13L, and the via connecting conductor portion 14L are formed so that the conductive layer 4L is positioned on the bottom surface 9L of the recess 3L is 70 ° C. and 50 kgf / cm ² . Crimped and processed into a disk shape having a diameter of 400 mm by end milling.
The processed laminate was fired at 1600 ° C. in the atmosphere. In addition, as a step of correcting the warp of the fired body, heat treatment was performed at 1560 ° C. in a reducing atmosphere in the presence of hydrogen gas and nitrogen gas.
An electrode terminal made of Kovar plated with nickel with a diameter of 2.5 mm and a length of 33 mm was used at 790 ° C. in a reducing atmosphere in the presence of hydrogen gas and nitrogen gas using a silver brazing material on the surface of the connecting intermediate layer 6L. I brazed.

(Example 2)
Instead of the connecting intermediate layer paste of Example 1, 95% platinum, yttria powder, organic vehicle, and 95% platinum connecting intermediate layer paste kneaded with calcium carbonate as an auxiliary agent were used. Thus, an electrostatic chuck was produced in the same manner as in Example 1 except that the connection intermediate layer was formed.

(Example 3)
The electrostatic chuck of the embodiment shown in FIG. 2 was prepared.
In order not to isolate the connection intermediate layer from the inner wall surface of the recess, the conductive layer paste was applied so that the conductive layer had a diameter of 6 mm after firing, and platinum was formed so that the connection intermediate layer became 7 mm after firing. An electrostatic chuck was produced in the same manner as in Example 1 except that 100% of the connection intermediate layer paste was applied.

Example 4
The electrostatic chuck of the embodiment shown in FIG. 1 was prepared.
Except that the via connection conductor and the internal conductive layer were not provided, and that the connection intermediate layer paste was coated with 100% platinum so that the connection intermediate layer had a diameter of 7 mm after firing. An electrostatic chuck was prepared as in 1.

(Example 5)
The embodiment shown on the left side of FIG. 7, that is, an electrostatic chuck having an aspect in which the electrode terminal is joined to the large-diameter portion side connection intermediate layer was prepared.
The via-connecting conductor part and the internal conductive layer were not provided, the concave part was divided into a small diameter part with a diameter of 2 mm and a large diameter part with a diameter of 10 mm, and the secondary conductive layer was coated with conductive paste In the same manner as in Example 1 except that it was formed by thermosetting at 200 ° C., and that the electrode terminal was brazed to the large-diameter side connection intermediate layer formed on the bottom of the large-diameter part. An electrostatic chuck was produced.

(Comparative Example 1)
An electrostatic chuck was produced in the same manner as in Example 1 except that the connection intermediate layer of Example 1 was not formed.

(Comparative Example 2)
Instead of the connection intermediate layer paste of Example 1, 90% platinum, yttria powder, organic vehicle, and 90% platinum connection intermediate layer paste obtained by kneading calcium carbonate as an auxiliary agent were used. Thus, an electrostatic chuck was produced in the same manner as in Example 1 except that the connection intermediate layer was formed.

  Table 1 shows the characteristics of the electrostatic chucks manufactured in Examples 1 to 5 and Comparative Examples 1 and 2. In Table 1, the “connection intermediate layer” is “intermediate layer”, and the state of isolation between the connection intermediate layer and the inner wall surface of the recess is indicated by “presence of voids”.

  About the produced electrostatic chuck, the movement of the platinum component of the conductive layer, the presence or absence of cracks, torque strength, and pin collapse strength were measured. The measurement results are shown in Table 2.

  In addition, about the movement of the platinum component of a conductive layer, when the cross section which cut | disconnected the electrostatic chuck was observed by the scanning electron microscope (the JEOL Co., Ltd. make, JSM-6400) with the measurement magnification of 200-1000 times, a conductive layer When the platinum component did not move from the inside to the surface, it was judged as “good”, and when it was moved, it was judged as “bad”. The presence or absence of cracks was confirmed by using a digital microscope (manufactured by Tohnichi Corporation, VHX-900) and a scanning electron microscope (manufactured by JEOL Ltd., JSM-6400). . Further, the torque strength was measured using a torque gauge (BTG36CN, manufactured by Tohnichi Corporation). Further, the pin collapse strength was measured with a tensile compression tester (manufactured by Imada Manufacturing Co., Ltd., SV-52N) with the measurement head speed set to 20 mm / min.

なお、実施例３〜５におけるクラックは、静電チャックを使用する上で問題とならない程度のクラックであり、実質的にクラックは無いとみなすことができる程度であった。

In addition, the crack in Examples 3-5 was a crack of the grade which does not become a problem when using an electrostatic chuck, and was a grade which can be considered that there is substantially no crack.

  In Examples 1 to 5 in which a layer containing 93% by volume or more of platinum was formed as the connecting intermediate layer, the brazing joint strength was high, and platinum did not move. Moreover, compared with Examples 3-5, the direction of Example 1 and 2 in which the edge part of a connection intermediate | middle layer and the inner wall face of a recessed part are isolated can suppress generation | occurrence | production of a crack more reliably. .

  Therefore, the electrostatic chuck according to the present invention can prevent the generation of cavities due to the movement of the platinum component in the conductive layer, can prevent high resistance and electrical non-conduction, and can further prevent cavities. By not generating, mechanical strength is not lowered. Furthermore, the electrostatic chuck according to the present invention has high bonding strength of the electrode terminals and can ensure high long-term reliability of the entire apparatus.

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1J, 1K, 1L Electrostatic chuck
2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2J, 2K, 2L
3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H, 3J, 3K, 3L Recess
4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H, 4J, 4K, 4L, 22G, 22H, 22J, 22K Conductive layer
5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5J, 5K, 5L Electrode terminals
6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, 6J, 6K, 6L Connection middle layer
7A, 7B, 7C, 7D, 7E, 7F, 7G, 7H, 7J, 7K, 7L
8A, 8B, 8C, 8D, 8E, 8F, 8G, 8H, 8J, 8K, 8L Opening
9A, 9B, 9C, 9D, 9E, 9F, 9G, 9H, 9J, 9K, 9L Bottom
10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10J, 10K, 10L Surface
11A, 11B, 11C, 11E, 11G, 11J, 11L brazing material
12A, 12B, 12C, 12D, 12E, 12F, 12G, 12H, 12J, 12K, 12L Holding surface
13B, 13E, 13F, 13J, 13K, 13L Internal conductive layer
14B, 14E, 14F, 14J, 14K, 14L Via connection conductor
15C, 15D, 15E, 15F, 15G, 15H, 15J, 15K Large diameter part
16C, 16D, 16E, 16F, 16G, 16H, 16J, 16K
17C, 17D, 17E, 17F, 17G, 17H, 17J, 17K Exposed surface
18C, 18D, 18E, 18F, 18G, 18H, 18J, 18K Shelf
19C, 19D, 19E, 19F, 19G, 19H, 19J, 19K Secondary conductive layer
20C, 20D, 20E, 20F, 20G, 20H, 20J, 20K Rise surface
21G, 21H, 21J, 21K Small diameter side connection intermediate layer
23G, 23H, 23J, 23K Large-diameter side connection intermediate layer
24L end
25L inner wall

Claims (5)

A plate-like substrate made of yttria-based ceramic;
A recess opening in one main surface of the substrate;
A conductive layer formed of platinum and a ceramic mainly composed of yttria exposed on the bottom surface of the recess;
An electrostatic chuck having an electrode terminal disposed upright in the recess and electrically connected to the conductive layer,
An electrostatic chuck comprising a connection intermediate layer containing 93% by volume or more of platinum formed between a surface of the conductive layer and the electrode terminal.   The electrostatic chuck according to claim 1, wherein the conductive layer is via-connected to an internal conductive layer disposed in the substrate. The concave portion is composed of a large diameter portion on the opening side of the concave portion and a small diameter portion subsequent thereto,
Secondary conductivity formed by extending from the surface of the connection intermediate layer formed on the surface of the conductive layer exposed on the bottom surface of the small diameter portion which is the bottom surface of the concave portion to the shelf portion which is the bottom surface of the large diameter portion. With layers,
The electrostatic chuck according to claim 1, wherein an electrode terminal is disposed so as to stand on the shelf, and the secondary conductive layer and the electrode terminal are electrically connected. The concave portion is composed of a large diameter portion on the opening side of the concave portion and a small diameter portion subsequent thereto,
A small diameter portion side connection intermediate layer formed on the surface of the conductive layer exposed on the bottom surface of the small diameter portion, which is the bottom surface of the recess,
A large-diameter side connection intermediate layer formed on the surface of the conductive layer formed exposed on the shelf that is the bottom surface of the large-diameter portion in the same recess;
A secondary conductive layer that electrically connects both the surface of the small diameter part side connection intermediate layer and the surface of the large diameter part side connection intermediate layer, and
The said secondary conductive layer currently formed in the surface of the said large diameter part side connection intermediate | middle layer, or the said large diameter part side connection intermediate | middle layer and an electrode terminal, The said any one of Claims 1-3 formed by electrically connecting The electrostatic chuck according to claim 1.   The end part of the connection intermediate | middle layer formed in the surface of the conductive layer formed exposed to the bottom face of the said recessed part, and the inner wall face of the said recessed part are isolated from the said any one of Claims 1-4. The electrostatic chuck described.

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