KR970003892B1 - Method of isolation of the elements on the semiconductor device - Google Patents

Abstract

An element separation method of a semiconductor device reduces a oxidation time and oxidation temperature in an element separation process of a bipolar element, and minimizes an up-phenomenon of a buried layer. The method includes the steps of: forming an epitaxial layer(3) on a semiconductor substrate(1); forming a first oxide layer(4) and a first silicon layer(5) on the epitaxial layer(3); patterning the first silicon layer(5) and the first oxide layer(4); etching the epitaxial layer(3) by using the first silicon layer(5) and the first oxide layer(4) as a mask; sequentially forming a second oxide layer(6), a polysilicon layer(10), a second silicon layer(7) and CVD oxide layer(8); etching back the CVD oxide layer(8) in order to make a surface of the polysilicon be exposed; selectively removing the second silicon layer(7); removing a remaining CVD oxide layer(8); performing an ion implantation with a high dose impurity about the polysilicon layer(10); forming an element separation oxide layer(9) on a predetermined area; and removing the remaining second silicon layer(7), polysilicon layer(10), first silicon layer(5) and the first oxide layer(4).