Patent ID: 6875558
Filing Date: 2005-04-05
Classification: C23C,H01L

Abstract:
1. A method of forming a trench isolation structure on a substrate, the method comprising: applying a pad oxide layer on said substrate; applying a polysilicon layer over said pad oxide layer; applying an anti-reflective coating (ARC) over said polysilicon layer; forming a photoresist on said ARC; exposing a portion of said photoresist to a light to define a location where a trench is to be formed; removing said photoresist at said location; etching, at said location, through said ARC, said polysilicon layer, said pad oxide and through a depth of said substrate to form a trench having a trench bottom at said location; removing a remainder of the photoresist; over filling the trench with a trench fill material, the trench fill material having a porous region located generally adjacent the ARC; and removing a portion of the trench fill material including removing the porous region.