DESIGN AND OPERATION OF A SPUTTERING SYSTEM FOR SUPERCONDUCTING PARTICLE DETECTOR MICROFABRICATION

A thesis submitted to the faculty of
San Francisco State University
in partial fulfillment of the
requirements for the
degree
 

Master of Science
in
Physics
 

by

Douglas David Hake

San Francisco, California

December, 1992

 

This thesis describes the motivation, design, and operation of a sputtering system which deposits superconducting films for dark matter detectors.  The sputtering system is an electropolished stainless steel vacuum chamber and load lock.  The chamber has three planar magnetron sputter cathodes which deposit thin films on three inch diameter silicon wafers.  Argon pressure is adjusted with a needle valve and a throttled cryopump.  Base pressures in the main chamber have reached 2 x 10-8 torr without bakeout.   The load lock is equipped with an oxygen input for tunnel barrier oxidations and an ion gun for precleaning.  A magnetically coupled load arm lifts and transfers a cube holding four wafers between rotatable platforms in the chamber and the load lock.  The platforms orient the wafers for ion gun precleaning and sputter depositions.  Thin film thickness and uniformity are characterized as functions of power and argon gas pressure.