Self-powered carrier for polishing or planarizing wafers

Abstract

A wafer carrier for polishing or planarizing semiconductor workpieces or wafers includes a pressure plate, an upper housing, and a lower housing. The pressure plate is configured to hold a wafer to be polished or planarized against a polishing pad, and further configured to rotate about the lower housing of the wafer carrier to rotate the wafer during the polishing or planarizing process. The wafer carrier includes an electric direct drive motor, with the stators of the motor disposed in the lower housing and the rotors of the motor disposed in the pressure plate, to rotate the pressure plate about the lower housing. Accordingly, when electric power is supplied to the stators of the direct drive motor, in response to the magnetic flux generated by the stators, the rotors of the motor rotate the pressure plate. The wafer carrier also includes a compliant material disposed between the upper housing and the lower housing of the wafer carrier to form a flexible joint which maintains the wafer in substantially parallel and in substantially full contact with the polishing pad. Additionally, the lower housing of the wafer carrier is pressurized to cause pressure to be applied across substantially all of the surface area of the pressure plate and substantially uniformly across the surface area of the wafer.