METHOD FOR FORMING TRENCH OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a trench of a semiconductor device is provided to improve an electrical characteristic of a semiconductor device by rounding an upper portion and a lower portion of a trench. CONSTITUTION: An insulating layer is formed on a semiconductor substrate(11). An insulating layer pattern and a trench are formed by etching the insulating layer and the semiconductor substrate(11). A lower corner of the trench is rounded by performing the first dry oxidation process and a wet oxidation process. A sacrificial insulating layer is formed on an upper portion of the whole structure. A spacer is formed at a sidewall of the trench by etching back the sacrificial insulating layer. An upper corner of the exposed trench is rounded by performing the second dry oxidation process. The spacer and the insulating layer pattern are removed.