METHOD FOR ISOLATING ELEMENT IN SEMICONDUCTOR DEVICE

摘要

PURPOSE: An isolation method for a semiconductor device is provided to guarantee an insulating characteristic of an insulating layer, by making upper portions at both sides of a trench round. CONSTITUTION: A pad oxide layer(12) and a silicon nitride layer(13) are sequentially formed on a semiconductor substrate(11). The silicon nitride layer and the pad oxide layer are patterned to expose an isolating region of the semiconductor substrate. The exposed portion of the semiconductor substrate is etched to form a trench. The resultant structure is cleaned to eliminate a part of the pad oxide portion at both sides of the trench. The exposed portion of the semiconductor substrate is thermally oxidized to form a round oxide layer(15).