Patent ID: 6589854
Filing Date: 2003-07-08
Classification: H01L

Abstract:
A method of forming a shallow trench isolation (STI) structure, comprising:providing a substrate; forming a pad oxide layer over the substrate; forming a mask layer over the pad oxide layer; patterning the substrate to form a trench in the substrate, wherein upper corners of the trench are rounded and a recess cavity is formed; conducting a high-density plasma chemical vapor deposition to form an insulation layer that covers mask layer and completely fills the trench, wherein the high-density chemical vapor deposition process is performed in two stages, a first stage and a second stage, wherein the first stage is carried out at a first etching/deposition ratio to fill the recess cavity and the second stage is carried out at a second etching/deposition ratio lower than that of the first stage to fill a remaining of the trench.