METHOD FOR FABRICATING ISOLATION LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating an isolation layer of a semiconductor device is provided to eliminate a deep moat at the upper edge of the isolation layer in wet-etching a pad nitride layer and a pad oxide layer by depositing and wet-etching an oxide layer after the pad nitride layer and the pad oxide layer are wet-etched. CONSTITUTION: The pad oxide layer and the pad nitride layer are sequentially formed on a semiconductor substrate(21). The pad nitride layer and the pad oxide layer are patterned to expose a substrate region corresponding to an isolation region. The exposed substrate region is etched to form a trench. A high density plasma(HDP) oxide layer is deposited on the resultant structure to completely fill the trench. A chemical mechanical polishing(CMP) process is performed on the HDP oxide layer until the pad nitride layer is exposed. The pad nitride layer and the pad oxide layer are wet-etched. An oxide layer is deposited on the resultant structure. The surface of the oxide layer is wet-etched.