Electrostatic chuck
AssigneeNgk Spark Plug Co., Ltd.
InventorsNaotoshi Morita, Ryosuke Kameyama
Life of this patent
Estimating the term…
Abstract
An electrostatic chuck including a metal base having a through hole; a ceramic body covering the through hole; a suction electrode provided in the ceramic body; and a heating element provided in the ceramic body. A projection region defined by projecting the through hole toward the ceramic body is differentiated from an outer region which is determined by magnifying the projection region at a similarity ratio of three while setting an areal center of gravity of the projection region as a center of similarity, but excluding an interior of the projection region. Furthermore, the heating element is arranged such that a heating value per unit area in the projection region is 50% or less of a heating value per unit area in the outer region.
Claims15
An electrostatic chuck comprising:
- a metal base having at least one through hole;
- a ceramic body covering said through hole;
- a suction electrode provided in said ceramic body;
- and
- a heating element provided in said ceramic body, wherein
- a heating value per unit area in a projection region of each of said at least one through hole is 50% or less of a heating value per unit area in an outer region, wherein said projection region is a region defined by projecting said through hole toward said ceramic body, and said outer region is a region determined by magnifying said projection region at a similarity ratio of three while setting an areal center of gravity of said projection region as a center of similarity, but excluding an interior of said projection region and wherein
- a lower surface of said ceramic body covers said at least one through hole and said ceramic body comprises:
- a concave portion formed in the lower surface of said ceramic body and in communication with said at least one through hole of said metal base, wherein an upper end of said concave portion is at a position that is lower than that of the heating element;
- a metallization layer formed in said concave portion;
- a conductive pattern connected to said metallization layer;
- and
- a via penetrating through a portion of said ceramic body and connecting said heating element and said conductive pattern.
An electrostatic chuck comprising:
- a metal base having at least one through hole;
- a ceramic body covering said through hole;
- a suction electrode provided in said ceramic body;
- and
- a heating element provided in said ceramic body,
- wherein said heating element is not present in a projection region of each of said at least one through hole defined by projecting said through hole toward said ceramic body and wherein
- a lower surface of said ceramic body covers said at least one through hole and said ceramic body comprises:
- a concave portion formed in the lower surface of said ceramic body and in communication with said at least one though hole of said metal base, wherein an upper end of said concave portion is at a position that is lower than that of the heating element;
- a metallization layer formed in said concave portion;
- a conductive pattern connected to said metallization layer, and
- a via penetrating through a portion of said ceramic body and connecting said heating element and said conductive pattern.
Dependencies are inferred from the claim text.