Ceramic joined body, electrostatic chuck device, and method for producing ceramic joined body
A ceramic joined body ( 1 ) includes: a pair of ceramic plates ( 2,3 ) that include a conductive material; a conductive layer ( 4 ) and an insulating layer ( 5 ) that are interposed between the pair of ceramic plates ( 2, 3 ); and a pair of intermediate layers ( 6, 7 ) that are interposed between the pair of ceramic plates ( 2, 3 ) and the conductive layer ( 4 ) and are in contact with the pair of ceramic plates ( 2, 3 ) and the conductive layer ( 4 ).
1. A ceramic joined body comprising:
a pair of ceramic plates that include a conductive material;
a conductive layer and an insulating layer that are interposed between the pair of ceramic plates;
a pair of intermediate layers that are interposed between the pair of ceramic plates and the conductive layer and are in contact with the pair of ceramic plates and the conductive layer; and
wherein when a thickness of the conductive layer is represented by t 1 and a total thickness of the intermediate layers is represented by t 2 , a thickness ratio R 1 of the intermediate layers which is defined by a following formula (1) is 3% or more,
R 1= t 2/ t 1×100(%) (1).
2. The ceramic joined body according to claim 1 ,
wherein the conductive layer is formed of a conductive material and an insulating material, and
the insulating layer and the intermediate layer are formed of an insulating material.
3. The ceramic joined body according to claim 2 ,
wherein an average primary particle diameter of the insulating material which forms the insulating layer is 1.6 μm or more and 10.0 μm or less.
4. The ceramic joined body according to claim 2 ,
wherein the insulating materials which are included in the conductive layer, the insulating layer, and the intermediate layer consist of aluminum oxide.
5. The ceramic joined body according to claim 2 ,
wherein the conductive material which is included in the conductive layer is at least one selected from the group consisting of MO 2 C, Mo, WC, W, TaC, Ta, SiC, carbon black, carbon nanotubes, and carbon nanofibers.
6. The ceramic joined body according to claim 1 ,
wherein the thickness ratio R 1 is 50% or less.
7. The ceramic joined body according to claim 1 ,
wherein the ceramic plate is formed of a composite body of aluminum oxide and silicon carbide.
8. An electrostatic chucking device,
wherein an electrostatic chuck member formed of a ceramic and a base member for adjusting a temperature formed of a metal are joined through an adhesive layer, and
the electrostatic chuck member is formed of the ceramic joined body according to claim 1 .
9. A method for producing the ceramic joined body according to claim 1 , comprising:
a step of preparing a first ceramic plate including a conductive material and a second ceramic plate including a conductive material;
a step of applying a paste for forming an intermediate layer to one surface of the first ceramic plate to form a first intermediate layer coating film;
a step of applying a paste for forming a conductive layer to a surface of the first intermediate layer coating film opposite to a surface thereof which is in contact with the first ceramic plate, to form a conductive layer coating film;
a step of applying a paste for forming an intermediate layer to a surface of the conductive layer coating film opposite to a surface thereof which is in contact with the first intermediate layer coating film, to form a second intermediate layer coating film;
a step of laminating the second ceramic plate on a surface of the second intermediate layer coating film opposite to a surface thereof which is in contact with the conductive layer coating film; and
a step of pressurizing a laminate including the first ceramic plate, the first intermediate layer coating film, the conductive layer coating film the second intermediate layer coating film, and the second ceramic plate in a thickness direction while heating the laminate.
10. The method for producing a ceramic joined body according to claim 9 , further comprising:
a step of applying a paste for forming an insulating layer to the surface of the first intermediate layer coating film to form an insulating layer coating film side by side with the conductive layer coating film, wherein the step is performed between. the step of forming the conductive layer coating film and the step of forming the second intermediate layer coating film.
11. The method for producing a ceramic joined body according to claim 10 , wherein
the paste for forming an intermediate layer is totally applied to the one surface of the first ceramic plate,
the paste for forming a conductive layer is partially applied to the surface of the first intermediate layer coating film,
the paste for forming an insulating layer is applied to the surface of the first intermediate layer coating film so that the insulating layer coating film surrounds the conductive layer coating film,
the paste for forming an intermediate layer is applied to the surface of the conductive layer coating film and a surface of the insulating layer coating film in order to form a second intermediate layer coating film.
12. The method for producing a ceramic joined body according to claim 9 , wherein
the paste for forming an intermediate layer is partially applied to the one surface of the first ceramic plate,
the paste for forming a conductive layer is applied to the surface of the first intermediate layer coating film,
the paste for forming an insulating layer is applied to the one surface of the first ceramic plate so that the insulating layer coating film surrounds the conductive layer coating film,
the paste for forming an intermediate layer is applied to the surface of the conductive layer coating film in order to form the second intermediate layer coating film, and
the second ceramic plate is laminated on the surface of the second intermediate layer coating film and a surface of the insulating layer coating film.
13. The method for producing a ceramic joined body according to claim 9 , wherein the first intermediate layer, the conductive layer, and the second intermediate layer are formed in the pressurizing step by volatilizing solvent included in the first intermediate layer coating film, the conductive layer coating film and the second intermediate layer coating film.
14. The ceramic joined body according to claim 1 ,
wherein the insulating layer is disposed on an outer periphery of a conductive layer,
the ceramic plate is formed of a composite body of aluminum oxide and silicon carbide,
the conductive layer is formed of aluminum oxide and molybdenum carbide,
the insulating layer is formed of aluminum oxide, and
the intermediate layer is formed of aluminum oxide.
15. The ceramic joined body according to claim 1 ,
wherein the ceramic plates have a circular shape or a donut shape in a plan view,
the conductive layer has a circular shape or a donut shape in a plan view, and
the insulating layer is disposed on an outer periphery of the conductive layer.
16. The ceramic joined body according to claim 1 ,
wherein the pair of intermediate layers are also interposed between the pair of ceramic plates and the insulating layer, and are in contact with the pair of ceramic plates and the insulating layer.
17. The ceramic joined body according to claim 1 ,
wherein upper and lower surfaces of the insulating layer are in contact with the pair of ceramic plates, and wherein the thickness ratio R 1 is 3% or more and 30% or less.
18. The ceramic joined body according to claim 1 ,
wherein the ceramic plates are made of a material which is at least one selected from a group consisting of an aluminum oxide sintered compact, an aluminum nitride sintered compact, and an aluminum oxide-silicon carbide composite sintered compact.
19. The ceramic joined body according to claim 1 ,
wherein the intermediate layers are formed of an insulating material which is at least one selected from a group consisting of aluminum oxide, aluminum nitride, yttrium oxide, and yttrium-aluminum-garnet.
20. The ceramic joined body according to claim 1 ,
wherein the intermediate layers consist of aluminum oxide.