NONVOLATILE MEMORY DEVICE AND METHOD FOR FORMING THE SAME

摘要

A nonvolatile memory device and a fabricating method thereof are provided to improve a programming speed and an erase operation speed by forming a p-type impurity of a floating gate layer with a low concentration. An isolation region(120) defining an active region is formed on a semiconductor substrate(100). A tunneling dielectric(130) is formed on the active region. A first preliminary polysilicon layer is formed to conformally cover the tunneling dielectric and the isolation region. A preliminary amorphous silicon layer conformally covers the first preliminary polysilicon layer. A second preliminary polysilicon layer covers the preliminary amorphous silicon layer. The second preliminary polysilicon layer, the preliminary amorphous silicon layer, and the first preliminary polysilicon layer are patterned to form a floating gate layer(140). When the first preliminary polysilicon layer is formed, a boron-doped polysilicon layer is formed.