METHOD FOR FORMING ISOLATION REGION OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming an isolation region of a semiconductor device is provided to improve a topology problem in a wide width region of a trench and a void problem in a narrow width region of the trench after performing a planarization process. CONSTITUTION: A semiconductor substrate(11) for forming an isolation region is exposed by forming a hard mask including an oxide layer(12) and a nitride layer(13) on an upper portion of the semiconductor substrate(11). A trench is formed by etching the exposed semiconductor substrate(11). A thin oxide layer(14) of high temperature and low pressure is deposited on the whole surface of the substrate(11). A thick BPSG(BoroPhosphoSilicate Glass) layer(15) is deposited on the thin oxide layer(14). The thick BPSG layer(15) is etched back and the thin oxide layer(14) is stripped. A thin oxide layer(16) of high temperature and low pressure is deposited on the whole surface. The thin oxide layer(16) is flattened and the nitride layer(13) and the oxide layer(12) are stripped.