METHOD FOR FORMING METAL LINE OF FLASH MEMORY SEMICONDUCTOR DEVICE

摘要

The method of forming the metal wiring in the flash memory device is provided to prevent the overhang of the diffusion barrier at the top part of the trench by the rounding the bottom part of the trench. The insulating layer(414) is formed on the semiconductor substrate(400). The insulating layer is etched and the trench is formed. The spacer layer is deposited on the semiconductor substrate including the trench surface. The spacer layer and the insulating layer are etched to remove the insulating layer with constant thickness. The spacer layer which is left behind in the trench sidewall is removed. The metallic plate for wiring is formed to bury the rounded trench.