Method for forming a cylindrical capacitor

Abstract

A method for forming a cylindrical capacitor of a dynamic random access memory cell is disclosed. The method includes firstly providing a semiconductor substrate having a dielectric layer thereon, at least one contact hole formed in the dielectric layer, wherein the contact hole extends from the top surface of the dielectric layer to the surface of the substrate. Next, a conductive layer is formed on the dielectric layer, and a blocking layer is further formed on the conductive layer. The conductive layer fills the contact hole, wherein at least one trench is formed in the blocking layer and a portion of the conductive layer, and wherein the trench locates approximately above the contact hole. Finally, an oxide layer is formed on the inner surface of the trench; and the blocking layer and a portion of the conductive layer are etched using the oxide layer as a mask, thereby forming a cylindrical electrode of the capacitor.

Dependencies are inferred from the claim text.