ELECTROSTATIC CHUCK FOR HOLDING A SEMICONDUCTOR WAFER

摘要

An electrostatic chuck for holding a simiconductor wafer flat in a charged particle beam machine has thermally conductive portions for supporting the wafer. An electrically conductive member, for example a grid, has parts which extend between the thermally-conductive portions and is separated from the wafer by a dielectric layer. The wafer is clamped against the chuck by the electrostatic force set up across the dielectric layer when a potential difference is applied between the conductive wafer and the conductive member. Heat generated in the wafer by the bombardment of charged particles can be dissipated readily via the thermally conductive portions. The wafer can be electrically contacted at its back surface if the portions are also electrically conductive. To enhance thermal conduction away from the wafer, the conductive portions can protrude from the dielectric layer.