Patent ID: 6303467
Filing Date: 2001-10-16
Classification: H01L

Abstract:
A method for manufacturing trench isolation, said method comprises following steps:providing a silicon substrate;forming a first dielectric material layer over said substrate;defining an isolation region over said substrate by photolithography and etching technique;forming a first isolating layer over said substrate having said isolation region;proceeding anisotropically etching to form a spacer around each of the two sides of said isolation region;forming a pad oxide layer over said substrate having said isolation region with said spacers formed around;forming a silicon nitride layer over said pad oxide layer;covering a mask over said silicon nitride layer, and proceeding anistropically etching in said isolation region to form a trench isolation;forming a second dielectric material layer over said whole substrate, thereby fill said second dielectric material into said trench isolation as isolating material therein;planarizing said second dielectric material layer by chemical mechanical polishing method; andremoving said second pad oxide layer and said second silicon nitride layer to form a trench isolation with a smooth corner in the crossing region between said trench isolation and said active area in said substrate.