Method for fabricating storage electrode of semiconductor device

Abstract

A method for fabricating a storage electrode of a semiconductor device, capable of forming the storage electrode to have a rough surface with hemispherical lugs by use of simplified deposition process and heat treatment using a single process tube to obtain a high capacitance in spite of a small cell area, thereby greatly improving the operation characteristic of the semiconductor device. The method includes the steps of bring a doped amorphous silicon film into contact with a portion of a substrate to be contact with the storage electrode, repeatedly forming an undoped amorphous silicon film and another doped amorphous silicon film over the doped amorphous silicon film at least one time, subjecting all the doped and undoped amorphous silicon films to a thermal treatment in an inert gas atmosphere for a time so that a dopant of each doped amorphous silicon film is diffused in a portion of the undoped amorphous silicon film while all the doped and undoped amorphus silicon films are crystallized into polysilicon films respectively; and etching the polysilicon films by use of a wet etch solution exhibiting an etch selectivity to an undoped one of the polysilicon film so that doped ones of the polysilicon films are etched at a higher rate than the undoped polysilicon film.

Dependencies are inferred from the claim text.