| 摘要 |
<p>PURPOSE:To cool a wafer directly and to enhance the effect of cooling by forming a refrigerant flow path in a ceramic layer forming the intermediate part of an electro static chuck substrate, and forming a refrigerant feeding flow path and a refrigerant returning flow path in a ceramic layer constituting the layer lower than the intermedi ate ceramic layer. CONSTITUTION:In an electrostatic chuck comprising a plurality of laminated ceramic layers 2, a refrigerant flow path 3 is formed in the intermediate ceramic layer 2a of a plurality of ceramic layers 2. In the ceramic layer 2b lower than said intermediate ceramic layer 2a, a feeding flow path 4 for sending the refrigerant into the refrigerant flow path 3 and a returning flow path 5 for draining the refrigerant from the refriger ant flow path 5 are formed. For example, the spiral shaped refrigerant flow path 3 is formed in said intermediate ceramic layer 2a. One end of the feeding flow path 4 is connected to the innermost side of the spiral shaped refrigerant flow path 3. One end of the flow path 5 is opened at the outermost end of the refrigerant flow path 3. The other ends of the feeding flow path 4 and the returning flow path 5 are opened at the lower surface of a substrate 1. The ceramic layer 2d at the uppermost stage becomes a dielectric layer which sucks a wafer W.</p> |
