Patent ID: 6221746
Filing Date: 2001-04-24
Classification: H01L

Abstract:
A method for forming a poly gate structures comprising steps of:providing a semiconductor substrate;forming a dielectric layer over said semiconductor substrate;forming a polysilicon layer over said dielectric layer;forming a metal silicide layer over said polysilicon layer;annealing said metal silicide layer, whereby said annealing let structure of said metal silicide layer transform to a stable structure that no phase transition happens during subsequent step;forming a passivation layer over said metal silicide layer;forming and patterning a photoresist layer on said passivation layer, said photoresist layer defining a poly gate region over said passivation layer;anisotropically etching portions of said polysilicon layer, said metal silicide layer and said passivation layer to form said poly gate using said photoresist layer as a mask, thereby exposing said dielectric layer;removing said photoresist layer;annealing said poly gate; andforming a smooth sidewall oxide on sidewall of said poly gate.