ENSURING A HIGH-DEGREE OF FLATNESS OF DIAMOND-POLISHED SEMICONDUCTOR WAFERS

This paper presents the results of studies of the effect of the polish ing wheel and the polishing medium on the flatness of gallium arsenide wafers. Recommendations are made for the periodic metering of oil to maintain the flatness of the wafers at a given level. On one hand, thi s enhances the efficiency of the polishing wheel, and, on the other ha nd, it reduces the consumption of scarce diamond pastes. It is shown t hat an estimate of the flatness of the wafers when they are diamond po lished to a depth of more than 30 mu m makes it possible to establish the degree of preparation of the processing equipment for operation an d to give recommendations regarding its use. (C) 1996 The Optical Soci ety of America.