| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a nonvolatile semiconductor storage device by which it can be possible to prevent a silicon oxide film formed on the side wall of a tungsten silicide film from swelling than that formed on the side wall of a polycrystal silicon film when oxidizing the side wall of a gate electrode, and to provide a nonvolatile semiconductor storage device having a desired gate electrode's shape that is obtained by the manufacturing method. SOLUTION: A tungsten silicide film 6 is etched at 4 to 10 mmTorr of pressure, at 200 to 400 W of RF source power and 100 to 200 W of bias power, and under a mixed gas of CF<SB>4</SB>/Cl<SB>2</SB>/N<SB>2</SB>at a flow rate of 1 to 50 sccm of CF<SB>4</SB>gas, 100 to 150 sccm of Cl<SB>2</SB>gas and 7 sccm or less of N<SB>2</SB>gas, and the tungsten silicide film 6 is made to have a constricted shape beforehand. Thus, even when the tungsten silicide film 6 is oxidized more than a first polycrystal silicon film 3 and a second polycrystal silicon film 5 during oxidation of the side wall of the gate electrode, a desired gate electrode's shape can be obtained. COPYRIGHT: (C)2008,JPO&INPIT
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