Method and structure for improving gas breakdown resistance and reducing

Abstract

The basic structure facilitates the flow of cooling gas or other heat transfer fluid to the surface of an electrostatic chuck addresses the problem of the RF plasma environment which seeks the interface between the electrostatic chuck dielectric surface layer and its underlying conductive layer, and includes an underlying conductive layer which contains at least one gas flow passageway and at least one dielectric layer overlying said conductive layer. The dielectric layer forms the upper surface of the chuck and contains at least one opening or passageway which connects with the fluid flow passageway in the conductive layer. The distance between the upper surface of the conductive layer and the upper surface of the chuck is greater in the area adjacent to the opening to a fluid flow passageway to the upper surface of the chuck. As a result, the dielectric layer thickness is greater in the area adjacent to the opening or passageway than at other locations on the surface of the chuck. The insulative dielectric structure as the upper surface of the chuck and improve the isolation of the dielectric surface from the underlying conductive layer. Typically, the conductive layer is an aluminum pedestal and the dielectric layer is a spray-applied alumina. Other materials can be used so long as they meet electrical requirements and their relative thermal coefficients of expansion do not create problems in the integrity of the electrostatic chuck after multiple cycles in the intended processing environment.