Patent ID: 6413828
Filing Date: 2002-07-02
Classification: H01L

Abstract:
A method of providing a substantially planar trench isolation region having rounded trench isolation/substrate corners, said method comprising the steps of:(a) forming a film stack on a surface of a substrate, said film stack comprising an oxide layer, a polysilicon layer and a nitride layer; (b) patterning said film stack so as to form at least one trench within said substrate, wherein said patterning exposes sidewalls of said oxide layer, polysilicon layer and nitride layer; (c) oxidizing the at least one trench and said exposed sidewalls of said oxide layer and said polysilicon layer so as to thermally grow a conformal oxide layer in said trench and on said exposed sidewalls of said oxide layer and said polysilicon layer; (d) filling said trench with a trench dielectric material; and (e) planarizing to said surface of said substrate.