METHOD FOR FORMING MULTI-TRENCH OF SEMICONDUCTOR DEVICE TO EASILY CONTROL RESISTANCE AND THRESHOLD VOLTAGE

摘要

PURPOSE: A method for forming a multi-trench of a semiconductor device is provided to easily control resistance and threshold voltage by using a plurality of trenches having different depth. CONSTITUTION: A hard mask composed of an oxide layer(12) and a nitride layer(14) is formed on a wafer(10). The first hard mask pattern with the first opening part is formed using the first photoresist pattern. The first trench(24) with a relatively deep depth is formed by selectively etching the wafer using the first hard mask pattern as a mask. The second hard mask pattern with the second opening part is formed using the second photoresist pattern as a mask. The second trench(32) with a relatively shallow depth is formed by using the second hard mask pattern as a mask.