Patent ID: 6436791
Filing Date: 2002-08-20
Classification: H01L

Abstract:
A method of forming a shallow trench isolation structure, comprising the steps of:providing a substrate having an upper surface; forming a pad oxide layer upon the substrate; forming a nitride layer over the pad oxide layer; the nitride layer having an upper surface; forming a trench by etching the nitride layer, pad oxide layer and a portion of the substrate; the trench having a bottom and side walls; depositing an oxide film upon the etched nitride layer surface, and the bottom and side walls of the trench; removing the oxide film from over the etched nitride layer surface, and the bottom of the trench to expose a portion of substrate within the trench; the removal of oxide film leaving oxide spacers over the trench side walls; selectively depositing epitaxial silicon over the exposed portion of substrate, completely filling the trench up to the upper surface of the substrate; forming a thermal oxide layer over the epitaxial silicon, annealing the interface between the epitaxial silicon and the oxide spacers; and removing the etched nitride layer and the pad oxide layer from over the etched substrate, the thermal oxide layer from over the epitaxial silicon and a portion of the oxide spacers extending above the surface of the etched substrate.