Method of thermal treatment of a wafer in an evacuated environment

Abstract

Semiconductor wafers are coated with metallic film by supporting the wafers individually adjacent a ring-shaped sputtering source. A vacuum chamber sputter coating apparatus has a number of work stations therein, at least one of which includes the ring-shaped sputtering source. Also included is a load lock; and an intermittently rotating vertical plate-like wafer carrier therewithin positioned closely adjacent the chamber entrance, and carrying wafers in turn from the load lock to the work stations. The carrier includes apertures each accepting a wafer therewithin in an upright position, with the wafers edgewise resiliently supported by clips. A chamber door is provided with a vacuum chuck to grasp a wafer presented vertically by a blade-like elevator which cooperates with a cassette and conveyor moving the cassette along a horizontal path below the chamber entrance. Closure of the door inserts the wafer into the clips within the carrier and chamber, and the reverse operation extracts a wafer previously coated at a sputtering work station. Both surfaces of the wafer can be accessed by processing equipment, for example, for wafer heating or cooling at some of the work stations. Thermal transfer for wafer heating or cooling is accomplished by introducing a gas at a pressure of approximately 100 to 1000 microns in a region between the wafer and a heating element or heat sink. The gas conducts thermal energy between the wafer and the heating element or heat sink.