METHOD FOR FORMING FIELD OXIDE LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a field oxide layer of a semiconductor device is provided to be capable of restraining bird's beak. CONSTITUTION: A pad oxide layer(12), a polysilicon layer(13) and the first nitride layer(14) are sequentially formed on a silicon substrate(11). A groove is formed to define a field oxide forming region by selectively etching the first nitride layer and the polysilicon layer. The second nitride layer(15) is formed on the resultant structure and the second nitride layer located at the bottom of the groove is selectively removed. A field oxide layer(16) is then formed by performing oxidation processing.