Patent ID: 6204109
Filing Date: 2001-03-20
Classification: H01L

Abstract:
A method for forming a cylindrical capacitor, said method comprising:providing a semiconductor substrate having a dielectric layer thereon, at least one contact hole formed in the dielectric layer, wherein said contact hole extends from a top surface of the dielectric layer to a surface of said substrate;forming a polysilicon layer on the dielectric layer, and a silicon nitride layer on said polysilicon layer, said polysilicon layer filling said contact hole, wherein at least one trench is formed in the silicon nitride layer and a portion of the polysilicon layer, and wherein said trench locates approximately above said contact hole;thermally forming an implantation-impurity-enhanced oxide layer on inner surface of said trench; andetching said silicon nitride layer and a portion of said polysilicon layer using said oxide layer as a mask, thereby forming a cylindrical electrode of the capacitor.