Patent ID: 6238997
Filing Date: 2001-05-29
Classification: H01L

Abstract:
A method of fabricating a shallow trench isolation, comprising sequentially the steps of:forming a pad oxide layer on the substrate;forming a mask layer on the pad oxide layer;forming a first oxide layer on the mask layer;forming a polysilicon layer on the first oxide layer;patterning the polysilicon layer, the first oxide layer, the mask layer, the pad oxide layer, and the substrate to form a trench exposing a portion of the substrate;forming a second oxide layer on the polysilicon layer to fill the trench;removing a first portion of the second oxide layer located on the polysilicon layer to expose the polysilicon layer;removing a second portion of the second oxide layer, and the polysilicone layer until the first oxide layer is exposed; andremoving a third portion of the second oxide layer, the first oxide layer, the mask layer, and the pad oxide layer to obtain a smooth substrate surface.