METHOD FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to improve an anisotropic etching characteristic and guarantee reliability of a dry etch process by changing only etch gas while using a conventional etching apparatus. CONSTITUTION: A lower layer is formed on a semiconductor substrate(10). A polycrystalline silicon layer(30) is formed on the lower layer. An etch mask layer is formed on the desired portion of the polycrystalline silicon layer and the undesired portion of the polycrystalline silicon layer is exposed. The undesired portion of the polycrystalline silicon layer is selectively etched by using predetermined etch gas whose main etch gas is CH3l.