METHOD FOR MANUFACTURING ISOLATION REGION OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing an isolation region of a semiconductor device is provided to overcome the limit of resolution of an exposure apparatus by growing an epi layer on a trench, and to improve a sub-threshold characteristic by making an upper corner of the trench gentle. CONSTITUTION: An oxide layer and a nitride layer are formed on a semiconductor substrate(21). A photoresist layer is deposited on the resultant structure, and patterned to make the positive photoresist layer remain only in an active region. The nitride layer and the oxide layer are sequentially etched to eliminate the photoresist layer by using the patterned photoresist layer as a mask. The exposed semiconductor substrate is etched to form a trench by using the nitride layer as a hard mask. An epi layer(24) is grown on the semiconductor substrate having the trench. An insulating layer(25) is formed on the resultant structure to completely fill the trench. The nitride layer is etched back, and the remaining nitride layer is etched away. The oxide layer and the insulating layer are etched for planarization.