METHOD FOR FORMING GATE ELECTRODE OF FLASH MEMORY DEVICE TO IMPROVE SCATTERING DEGREE OF CELLS AND PREVENT GENERATION OF POLYSILICON RESIDUES

摘要

PURPOSE: A method for forming a gate electrode of a flash memory device to improve a scattering degree of cells and prevent generation of polysilicon residues is provided to improve a scattering degree of threshold voltage characteristics of a memory cell transistor by forming uniformly a gate oxide layer on the first silicon layer pattern and an upper surface of a substrate. CONSTITUTION: A field oxide layer pattern(110) is formed on a semiconductor substrate(100). A nitride layer is formed on the semiconductor substrate and the field oxide layer pattern. A nitride layer spacer is formed by etching back the nitride layer. A gate oxide layer(114) is formed on a surface of the exposed semiconductor substrate. The first polysilicon layer pattern is formed on the nitride layer spacer and the gate oxide layer. A dielectric layer and the second polysilicon layer are formed on the first polysilicon layer pattern and the field oxide layer pattern. A gate electrode is formed by patterning the second polysilicon layer, the dielectric layer, and the first polysilicon layer pattern.