Patent ID: 6197659
Filing Date: 2001-03-06
Classification: H01L

Abstract:
A process of fabricating a shallow trench isolation structure comprising the steps of:providing a substrate;forming an insulating layer over said substrate;forming a nitride masking layer over said insulating layer;patterning and etching said nitride masking layer and said insulating layer to expose a portion of said substrate, and to expose edges of said nitride masking layer and said insulating layer, said exposed portion of said substrate substantially defining boundaries of the isolation structure;depositing a first oxide layer superjacent said exposed portion of said substrate, and over said nitride masking layer;removing portions of said first oxide layer lying over said nitride masking layer, a central portion of said first oxide layer superjacent said substrate, and a portion of said substrate to form a trench having a sidewall and a bottom, leaving an oxide spacer disposed between said exposed edges of said nitride masking layer and said insulating layer, and the edge of said trench;forming a second oxide layer on the sidewall and bottom of said trench;depositing an insulating material into said trench, over said spacer, and over said first oxide layer to form a third oxide layer;planarizing said third oxide layer to expose said nitride masking layer;removing said nitride masking layer;removing said insulating layer; andsmoothing said third oxide layer and only a portion of said spacer to form the trench isolation structure.