Patent ID: 6110800
Filing Date: 2000-08-29
Classification: H01L

Abstract:
A method to form a trench isolation structure, the method comprising:forming a trench on a semiconductor substrate by photolithography and etching;sequentially forming a pad oxide layer and a silicon nitride layer over the substrate;forming a polysilicon side-wall spacer on each side of the trench;oxidizing the polysilicon side-wall spacer to form an oxide side-wall spacer on each side of the trench;repeating the step of forming the polysilicon side-wall spacer and the step of oxidizing it to form the oxide side-wall spacer until the oxide side-wall spacer fills the trench to form an oxide plug; andremoving a portion of the pad oxide layer and the silicon nitride layer above the substrate other than the trench and a top portion of the oxide plug above the surface of the substrate.