Method of selective oxidation in semiconductor manufacture

摘要

Disclosed is a method of selective oxidation of components of a semiconductor transistor containing silicon in the presence of high conductivity metal or metal alloys. A high temperature annealing step allows hydrogen gas to permeate the surface of a metal or metal alloy and creates a hydrogen-terminated passivation layer that surrounds the metallic layer. This passivating layer protects the underlying metal or metal alloy from oxidation by oxygen or water and reduces any oxidized metal present back into the constituent metal or metal alloy. In a subsequent wet oxidation step the source and drain regions of a semiconductor transistor gate electrode are reoxidized without oxidation of the passivated metal or metal alloy. The process does not consume the metal or metal alloy layer, insures that the overall gate electrode resistance remains low, and preserves the desirable characteristics of the gate electrode that insure a quality component with superior longevity.