METHOD FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to improve process yield and reliability of a device operation by improving cohesion between a well oxide layer and a linear nitride layer and between linear oxide layers in an STI(shallow trench isolation) process using the linear nitride layer and by reducing the stress of a field oxide layer and decreasing the stress among layers. CONSTITUTION: A pad oxide layer and a pad nitride layer are sequentially formed on a semiconductor substrate. The pad nitride layer and the pad oxide layer are selectively etched by a patterning process using an isolation mask to form a pad nitride layer pattern exposing a reserved portion for an isolation region of the semiconductor substrate. A predetermined thickness of the substrate exposed by the pad nitride layer is etched to form a trench. A well oxide layer, a linear nitride layer and a linear oxide layer are sequentially formed on the resultant structure. A field oxide layer is formed on the resultant structure to fill a trench. The field oxide layer is planarized. The pad nitride layer pattern is eliminated. The field oxide layer is formed by an HDPCVD(high density plasma chemical vapor deposition) method wherein bias power of 1-1.3 kilowatt is applied in a main applying process of an HDPCVD apparatus.