METHOD OF FORMING AN ISOLATION IN SEMICONDUCTOR DEVICE

摘要

A method for forming an element isolation layer of a semiconductor device is provided to gap-fill a trench without a void by preventing the generation of the void by forming an insulating layer. A tunnel insulating layer(102) and a charge storing layer are formed in an active region. A semiconductor substrate(100) with a trench is provided in an element isolation region. A first insulating layer(114) is formed to fill the lower part of the trench. A porous second insulating layer(116) is formed on the first insulating layer to fill the space between the charge storing layers. A third insulating layer(118) with higher density than the second insulating layer is formed in a lateral wall of the trench and the second insulating layer. A porous forth insulating layer(120) is formed to fill the trench.