METHOD OF FORMING A FLOATING GATE ELECTRODE IN FLASH MEMORY DEVICE

摘要

A method for forming a floating gate electrode of a flash memory device is provided to suppress occurrence of seams in a first polysilicon layer deposition process by securing a first polysilicon layer region. A nitride layer for hard mask is formed on a semiconductor substrate(10). A trench is formed by patterning the nitride layer and the semiconductor substrate. An insulating layer for burying the trench is formed on the entire surface of the semiconductor substrate. An oxide layer for burying the trench is formed within the trench by a planarization process. The nitride layer and the oxide layer are removed by a first etch process. A first polysilicon layer region for floating gate electrode is defined by forming the oxide layer on a top corner. A first polysilicon layer(18) for floating gate is formed thereon.