METHOD FOR FORMING TRENCH OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming the trench of a semiconductor device is provided to secure a U-shaped trench by using a double etching process consisting of a preliminary process and a main etching process without the generation of a corner pit. CONSTITUTION: A preliminary etching mask(22) is formed to expose the center part of a trench formation region in the surface of a semiconductor wafer(10). A preliminary etching process is performed on the exposed surface of the semiconductor wafer by using the preliminary etching mask with a first etch depth. The preliminary etching mask is removed. A main etching mask(23,24) is formed to expose the trench formation region. An additional main etching process is performed on the exposed semiconductor wafer by using the main etching mask with a preset trench formation depth. [Reference numerals] (AA) Preliminary etching region; (BB) Preliminary etching depth; (CC) Trench forming depth; (DD) Trench forming region