METHOD OF FORMING ISOLATION LAYER OF SEMICONDUCTOR DEVICE TO PREVENT GENERATION OF TRAP SITE OF LOWER PART OF TRENCH

摘要

PURPOSE: A method of forming an isolation layer of a semiconductor device is provided to prevent the generation of a trap site by removing a liner nitride layer from a lower part of a trench. CONSTITUTION: A trench is formed in a silicon substrate(200) by using a pad nitride layer as a hard mask. A liner oxide layer(240) and a liner nitride layer(250) are sequentially formed within the trench. The liner nitride layer is removed from a lower part of the trench and a round oxide layer is formed on the lower part of the trench by oxidation. The round oxide layer is removed therefrom in order to form the lower part of the trench having a round shape.