METHOD FOR FORMING ISOLATION REGION OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming an isolation region of a semiconductor device is provided to improve the operating quality and the productivity of the semiconductor device by removing an oxynitride layer formed on a nitride layer without performing a separate etching process. CONSTITUTION: A pad oxide layer(12), a nitride layer(14) and an oxynitride layer(16) are sequentially formed on a semiconductor substrate(10). By using a photoresist pattern(10) for a mask, the oxynitride layer(16), the nitride layer(14) and the pad oxide layer(12) on an isolation region are sequentially removed so that the semiconductor substrate(10) is exposed. Then, a trench(20) is formed by etching the exposed semiconductor substrate(10), by which the oxynitride layer(16) is also removed. The trench(20) is filled by forming an oxide layer(22) on the surface of the structure. After the oxide layer(22) formed on the nitride layer(14) is removed by a CMP process, the nitride layer(14) is removed.