| 摘要 |
PROBLEM TO BE SOLVED: To see that the high melting point metal used for a gate electrode is not corroded by cleaning with chemicals, by equipping a semiconductor device with the gate electrode including the high melting point metal whose sidewall is nitrided. SOLUTION: A gate electrode 8 is made on a silicon substrate 1 by dry- etching a silicon nitride film 6, a tungsten film 5, a tungsten nitride film 4, and a polysilicon film 3. Next, a silicon substrate 1 is cleaned in hydrofluoric water to remove polymetal gate etching reaction products adhering to a wafer. Next, a tungsten nitride sidewall protective film 5a is made at the sidewall of this tungsten film 5 by nitriding the exposed face, that is, the sidewall of the tungsten film 5 constituting the gate electrode 8. Next, organic matter adhering to the surface of the wafer is removed by cleaning the silicon substrate 1 in sulfuric acid hydrogen peroxide water mixed solution, Here, since a tungsten nitride film sidewall protective film 5a is made at the the sidewall of the tungsten film 5, the corrosion of the gate electrode 8 does not occur.
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