METHOD OF FORMING CYLINDRICAL CHARGE STORAGE ELECTRODE IN SEMICONDUCTOR ELEMENT

摘要

PURPOSE: A method of forming a cylindrical charge storage electrode is to form a uniform thickness of a sacrificial film with respect to a wafer, thereby increasing a reliability of the semiconductor element. CONSTITUTION: A method of forming a cylindrical charge storage electrode comprises the steps of: forming a conductive film for making the cylindrical charge storage electrode on a substrate; forming a sacrificial film(41) on the conductive film; forming a photoresist on the sacrificial film; hard-baking the photoresist; dry-etching the photoresist until the sacrificial film is exposed; and dry-etching the remaining photoresist and a portion of the exposed sacrificial film. A selectivity of the photoresist with respect to the sacrificial film is maintained to be within the range of 0.8 to 1.2. The selectivity of the remaining photoresist with respect to the sacrificial film is substantially maintained to be 1.