TRENCH FORMING METHOD FOR SEMICONDUCTOR DEVICE

摘要

PURPOSE: A trench forming method for a semiconductor device is provided to form a self-aligned trench by selectively forming an epi-layer on a silicon substrate not using dry-etching for the trench to form a capacitor of the semiconductor device. CONSTITUTION: The trench forming method for a semiconductor device comprises: a step to form a dummy layer pattern on a silicon substrate; a step to form a first epi-layer(23) on the surface of the semiconductor substrate(21) having no the dummy layer pattern; a step to form a first trench by deleting the dummy layer pattern; and a step to form a second trench by forming a second epi-layer(24) on the surface of the first epi-layer remained and the surface of the first trench.