Process for electropolishing semiconductor surfaces

Claim 1

A PROCESS FOR ELECTROPOLISHING A SURFACE HAVING HIGH POINTS AND DEPRESSIONS THEREIN, SAID PROCESS COMPRISING THE STEPS OF MOUNTING ECCENTRICALLY ON A FIRST DISK A SEMICONDUCTOR WAFER FOR EXPOSING A SURFACE OF SAID WAFER, SAID DISK BEING CAPABLE OF ROTATION ABOUT A FIRST CENTRAL AXIS, SPACING SAID EXPOSED SURFACE OF SAID MOUNTED SEMICONDUCTOR WAFER FROM A SECOND DISK, SAID SECOND DISK BEING CAPABLE OF ROTATION ABOUTA SECOND CENTRAL AXIS, SAID FIRST AND SAID SECOND AXES BEING NONCOINCIDENT, FIXING A CLOTH TO SAID SECOND DISK, SAID CLOTH HAVING A PILE LESS THAN A ABOUT .030 INCH, SPACING THE TOP OF SAID PILE A DISTANCE FROM A PLANE THROUGH THE HIGH POINTS OF SAID SURFACE OF BETWEEEN THREE TIMES AND A THIRD THE DEPTH OF THE AVERAGE DEPRESSION, INTRODUCING AN ELECTROLYTE FOR FILLING THE SPACE BETWEEN SAID SEMICONDUCTOR WAFER AND SAID SECOND DISK, INITIATING A CURRENT FLOW BETWEEN SAID SEMICONDUCTOR WAFER AND SAID SECOND DISK, SAID CURRENT FLOW BEING OF A DIRECTION FOR MAINTAINING SAID WAFER POSITIVE WITH RESPECT TO SAID SECOND DISK, AND ROTATING SAID FIRST AND SECOND DISK FOR A TIME TO REMOVE THE HIGH POINTS FROM SAID SURFACE OF SAID WAFER.