METHOD FOR FORMING AN ISOLATION LAYER OF SEMICONDUCTOR DEIVCES

摘要

PURPOSE: An isolation layer formation method is provided to prevent an active region shrinkage due to bird's beak formed by LOCOS(LOCal Oxidation of Silicon). CONSTITUTION: The method comprises the steps of: exposing an active region of a semiconductor substrate(11) by etching a pad oxide layer(12) and a pad nitride layer(13) formed on the semiconductor substrate; forming an under-cut at lower portion of the pad nitride layer(13) by cleaning process; forming a first silicon layer(14) to fill the under-cut; forming a first silicon spacer(15) and simultaneously etching the exposed semiconductor substrate(11) by etching the first silicon layer; depositing a second silicon layer(16) and forming a second silicon spacer(17) by etching the second silicon layer; forming a field oxide layer(18) by performing an oxidation process; and removing the pad oxide and the pad nitride layers(12,13).