DEVICE FABRICATION BY PLASMA ETCHING WITH LESSENED LOADING EFFECT

摘要

1 MOGAB, C.J. 4 DEVICE FABRICATION BY PLASMA ETCHING WITH LESSENED LOADING EFFECT Plasma etching as applied to many of the materials encountered in the fabrication of LSI's is complicated by loading effect-the dependence of etch rate on the integrated surface area to be etched. This problem is alleviated by appropriate choice of etchant and etching conditions. Appropriate choice of system parameters, generally most concerned with the inherent lifetime of etchant species, may also result in improvement of etch rate uniformity on a wafer-by-wafer basis. In accordance with this invention this is accomplished by selecting a gaseous matter so that a primary etchant species, which causes the etching by reaction with the surface being etched, has a mean inherent lifetime within the plasma which is no more than one tenth as great as the mean lifetime due to chemical reaction with the surface resulting in etching.