Method of making a workpiece at a uniform potential during cathode sputtering

Claim 1

IN A METHOD OF SPUTTERING A UNIFORM DEPOSIT ON A PLANAR WORKPIECE, INCLUDING PROVIDING A SPUTTERING ENVIRONMENT OF AN IONIZABLE GAS, AND IN SAID ENVIRONMENT, A CATHODE STRUCTURE HAVING A SUBSTANTIALLY PLANAR DISCHARGE SURFACE, A WORKPIECE SUPPORTED ON AN ANODE STRUCTURE HAVING A SUBSTANTIALLY PLANAR SURFACE SUBSTANTIALLY PARALLEL TO THE DISCHARGE SURFACE OF THE CATHODE STRUCTURE, AND CAUSING A SPUTTERING ELECTRICAL DISCHARGE TO BE SUPPORTED BETWEEN SAID SURFACES BY APPLYING RADIO FREQUENCY VOLTAGE BETWEEN SAID CATHODE AND SAID ANODE; THE IMPROVEMENT WHEREIN SAID WORKPIECE IS RECESSED IN SAID ANODE SO THAT THE SURFACES OF SAID ANODE AND SAID WORKPIECE ARE SUBSTANTIALLY COPLANAR AND SAID ANODE AND CATHODE ARE IN JUXTAPOSED RELATIONSHIP AND SPACED APART SO THAT SAID ANODE SURFACE IS NEAR TO BUT NOT WITHIN THE DARK SPACE OF THE SPUTTERING DISCHARGE. WHEREBY SAID COPLANAR WORKPIECE SURFACE AND SAID ANODE SURFACE ARE AT EQUAL POTENTIAL.