Patent ID: 6063690
Filing Date: 2000-05-16
Classification: H01L

Abstract:
A method of manufacturing an electrically-insulating field oxide region in a semiconductor substrate, comprising:forming a pad oxide layer on a surface of the substrate;depositing a layer of polysilicon on a surface of the pad oxide layer;depositing a silicon nitride layer on a surface of the polysilicon layer;removing a portion of the silicon nitride layer and a portion of the polysilicon layer over a portion of the substrate;forming a first field oxide layer at the portion of the substrate where the silicone nitride layer and the polysilicon layer were removed;removing the first field oxide layer from the portion of the substrate;forming a second field oxide layer at the portion of the substrate where the first field oxide layer was removed;removing the silicone nitride layer;forming a third field oxide layer on the surface of the second field oxide layer; andremoving part of the third field oxide layer.