Hesitation free roller

摘要

A method and apparatus for rotating wafers in a scrubber, wherein both sides of a wafer are scrubbed without slipping or hesitating. A rotating roller imparts rotary motion to a semiconductor wafer during a cleaning process wherein both sides of a wafer are scrubbed. The rotating roller and wafer contact at their outer edges and the friction between their outer edges causes the wafer to rotate. The roller has an outer edge with a groove. The wafer edge is pinched inside the groove to create enough friction that when cleaning solutions are applied the wafer does not slip and continues to rotate. Also, the groove allows the roller to pinch the wafer just enough so that when the roller reaches the flat of the wafer, the roller may regain the radius of the wafer without hesitating.