Patent ID: 6541350
Filing Date: 2003-04-01
Classification: H01L

Abstract:
A method for forming shallow trench isolation, comprising the steps of:forming a pad oxide layer on a substrate; forming a mask layer on said pad oxide layer; forming an opening through said mask layer and said pad oxide layer such that regions of said substrate are exposed; etching said exposed regions to form trenches inside said substrate; implanting nitrogen ions into the sidewall of said trenches to form a silicon nitride layer; forming a siliconoxynitride layer on said sidewall of said trenches after said step of implanting nitrogen ions; forming a silicon oxide layer on said siliconoxynitride layer and said mask layer; removing the excess portion of said silicon oxide layer over said mask layer to expose said mask layer; removing said mask layer; and removing said pad oxide layer by using hydrofluoric acid (HF).