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 and to minimize reduction of an active region due to bird's beak. CONSTITUTION: An anti-oxidation layer including a pad oxide layer(20) and a nitride layer(30) is formed on a semiconductor substrate(10). The anti-oxidation layer is etched by using a photoresist pattern, wherein the thickness of the photoresist pattern is a relatively thick in view of reflow processing. The photoresist pattern reflows. A trench is formed by etching the substrate using the reflowing photoresist pattern as a mask. Then, a field oxide layer(40) is formed by thermal oxidation processing.