METHOD OF FABRICATING FOR A VLSI SEMICONDUCTOR MEMORY DEVICE

摘要

This method secures enough capacitor in the limited area when a semiconductor memory device is highly integrated and obtains wanted capacitance easily with a simple process. The method comprises the steps of: forming an insulating layer on the substrate; diffusing polycrystal silicon layer with rough surface on the insulating layer; etching selectively the polycrystal silicon layer and the insulating layer with rough surfaces by etch-back; filling the etched region with some filling material; etching the rough surfaces of polycrystal silicon layer, the insulating layer, and the substrate by the selective etching process with the filling material as a mask; and forming a fine deep hole in high concentration on the substrate.