| 摘要 |
PROBLEM TO BE SOLVED: To prevent damage on the surface of a floating gate upon forming the floating gate employing doped polysilicon. SOLUTION: In the manufacturing method of the semiconductor memory device, a silicon film 115 into which impurities are introduced for the floating gate, a protective film 121, a silicon nitride film 122 for a lamination hard mask, and a first NSG film 123 are formed for the floating gate to form a required pattern. Then a second NSG film 125 is formed thereon to leave as a side wall 125a, and the etching of the silicon nitride film 122 is effected by employing the side wall 125a as a mask. Further, the etching of the silicon film 115 is effected by employing the side wall 125a as a mask to form a silicon pattern while the surface of the silicon pattern is covered by a second protective film 126 to remove the silicon nitride film 122 through etching. COPYRIGHT: (C)2005,JPO&NCIPI
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