METHOD FOR FABRICATING SEMICONDUCTOR DEVICE TO AVOID DEFECT IN BOUNDARY REGION AND PREVENT LEAKAGE CURRENT FROM INCREASING

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to avoid a defect in a boundary region and prevent a leakage current from increasing by controlling the depth of a moat formed at the edge of an isolation region of a substrate in an STI(shallow trench isolation) process. CONSTITUTION: A pad nitride layer pattern overlapping a pad oxide layer(32) is formed on a semiconductor substrate(30). The semiconductor substrate exposed by the pad nitride layer pattern is etched to form a trench wherein a top corner to which the upper part of the trench is exposed is generated. A well oxide layer(38) is formed on the sidewall of the trench. A liner nitride layer is formed on the resultant structure. The liner nitride layer is etched back so that it remains as a spacer type on the sidewall of the trench but the liner nitride layer is eliminated in the top corner part and the bottom of the trench. A field oxide layer is formed on the resultant structure. The upper part of the filed oxide layer is etched to expose the pad nitride layer pattern. The pad nitride layer pattern is removed.