Encapsulation method for localized oxidation of silicon.

摘要

An improved LOCOS isolation process is disclosed wherein an oxidizable layer (34) is conformably deposited to overlie a silicon nitride oxidation mask (28). In accordance with one embodiment of the invention, a composite layer comprising a buffer layer (31) and an oxidation resistant material (28) is patterned to form an oxidation mask on a silicon substrate (20). A layer of an oxidizable material (34) is conformably deposited to overlie the oxidation mask. During the oxidation process used to form electrical isolation structures (36) in the substrate (20), a substantial reduction in lateral oxidation encroachment is realized.