Patent ID: 6258692
Filing Date: 2001-07-10
Classification: H01L

Abstract:
A method of forming shallow trench isolation comprising the steps of:providing a substrate;forming a pad oxide layer on the substrate;forming a first mask layer on the pad oxide layer;forming a second mask layer on the first mask layer;forming an opening in the second mask layer, the first mask layer and the pad oxide layer;forming a trench in the substrate with the second mask layer serving as a hard mask;forming a liner oxide layer on the surface of the trench and forming protective oxide layers on the edges of the first mask layer;forming a buffer layer conformal to the substrate;forming an insulating layer over the buffer layer, wherein the insulating layer completely fills the trench;removing part of the insulating layer, leaving part thereof on the buffer layer;removing part of the remaining insulating layer, part of the buffer layer, and the second mask layer;removing the first mask layer; andremoving the pad oxide layer.