Trench-diffusion corner rounding in a shallow-trench (STI) process

摘要

An isolation structure on an integrated circuit is formed using a shallow trench isolation process. A layer of buffer oxide is formed on a substrate. A layer of nitride is formed on the layer of buffer oxide. The layer of nitride and the layer of buffer oxide are patterned to form a trench area. An oxidation of the substrate is performed to provide for round corners at a perimeter of the trench area. The substrate is then etched to form a trench within the trench area.