Wafer transfer system

Abstract

A system for the automated transfer of semiconductor wafers between a cassette and a wafer processing chamber. Included in the system are a cassette conveyor assembly, a wafer transfer assembly and a wafer handling assembly associated with the entrance to the processing chamber. Wafers of any standard size can be accommodated by the system. The cassette conveyor assembly includes a cassette holder which retains and precisely positions two standard plastic cassettes. The cassette holder is positioned by a ball reverser driven by a motor and a mechanical stepper. The wafer transfer assembly includes an elevator blade which vertically raises and lowers wafers to and from the wafer handling assembly. The elevator blade is actuated by a crank driven by a motor and a mechanical stepper. The crank provides a high rate of wafer transfer and a low risk of wafer damage.

Dependencies are inferred from the claim text.