METHOD FOR FORMING ISOLATION LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming an isolation layer of a semiconductor device is provided to improve topology of the isolation layer by using spacer etching property. CONSTITUTION: A pad oxide layer(32) and an insulating layer are sequentially formed on a semiconductor substrate(31). By selectively etching the insulating layer, an insulating pattern(33) is formed. A spacer(14) with a relatively high etching selectivity is formed at both sidewalls of the insulating pattern. A trench(35) is formed by selectively etching the exposed substrate using the pad oxide layer and the spacer as an etch barrier. At this time, the spacer is simultaneously removed. Then, an isolation layer is formed in the trench.