METHOD FOR FORMING TRENCH OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a trench of a semiconductor device is provided to obtain uniform isolation layers regardless of the widths of trenches by forming a photoresist pattern on an oxide layer of a wide isolation region and carrying out an etching process for the entire oxide layer. CONSTITUTION: A pad oxide and a nitride layer(12,13) are sequentially formed on a semiconductor substrate(11). Trenches having different widths are formed in the substrate by selectively etching the resultant structure. An oxide layer(14) is formed on the resultant structure for completely filling the trenches. A photoresist pattern(15) is formed on the oxide layer of a wide isolation region. At this time, the oxide layer of a narrow isolation region is exposed to the outside. An etching process is carried out on the exposed oxide layer by using the photoresist pattern as an etching mask until the entire oxide layer has a uniform thickness.