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 improving junction leakage current and GOI(Gate Oxide Integrity) properties by using two-step oxidation processing for trench corner rounding. CONSTITUTION: After forming sequentially a pad oxide pattern(22) and a pad nitride pattern(23) on a semiconductor substrate(21), a trench is formed in the substrate. After cleaning the trench, the first oxide layer is formed on the trench by performing low-temperature oxidation processing for bottom corner rounding of the trench. The second oxide layer(25) is formed on the trench by performing high-temperature oxidation processing for top corner rounding of the trench. Then, an isolation layer is formed in the trench.