Method of forming a charge storage electrode having a selective hemispherical grains silicon film in a semiconductor device

Abstract

The present invention relates to semiconductor manufacturing field, more particularly, to a process of forming a charge storage electrode to which a selective hemispherical grains (HSG) silicon film is applied. The object of the present invention is to provide a method of forming a charge storage electrode having the selective HSG silicon film in semiconductor device which can secure a sufficient capacitor effective surface area by obtaining desired grain size at the time of selective HSG silicon film formation. The present invention prevents remaining of carbon component which obstructs the growth of HSG silicon film after dry etching process by limiting the carbon halide gas used in dry etching process of amorphous silicon film for defining the charge storage electrode at the time of process of forming the charge storage electrode having selective HSG silicon film. That is, the present invention is a technology of etching a part of amorphous silicon film by using general carbon halide gas at the time of dry etching process of the amorphous silicon film for defining the charge storage electrode, and then, finally etching the remaining part of amorphous silicon film by using silicon etching gas such as SF,gas, Cl,+O,gas, HBr gas, etc. not containing carbon component or only using the etching gas such as SF,gas, Cl,+O,gas, HBr gas, etc. not containing carbon component during selective etching of amorphous silicon film.