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 be capable of reducing stress and minimizing moat phenomenon by partially forming a nitride oxide layer at a sacrificial oxide layer using a plasma doping process. CONSTITUTION: A pad oxide layer(110a) and a nitride layer(120a) are sequentially formed at the upper portion of a semiconductor substrate(100). A trench(130) is formed at the resultant structure by carrying out an etching process. A sacrificial oxide layer(140) is formed on the entire surface of the resultant structure. A nitrogen ion implantation is carried out at the sacrificial oxide layer. A heat treatment is then carried out at the sacrificial oxide layer for partially transforming the sacrificial oxide layer into a nitride oxide layer(150). An isolation layer is formed by completely filling gap-fill material at the inner portion of the trench.