METHOD OF FORMING ISOLATION FILM OF SEMICONDUCTOR MEMORY DEVICE

摘要

A method of forming an isolation film of a semiconductor memory device are provided to protect a side wall of charge storage layer while etching by forming a trench and forming a protective film on the side wall and bottom of the trench. A semiconductor substrate(100) is composed of a tunnel insulating layer(101a) and a charge storage layer. An element isolating trench(105) is formed by etching the charge storage layer(102a), a tunnel insulating layer, and the semiconductor substrate. A protection layer(107a) is formed on the overall structure including the element isolating trench, and the first insulating layer(108a) is formed on the bottom of the trench including the protective layer.