| 摘要 |
PROBLEM TO BE SOLVED: To prevent abnromal oxidation of a WSix film surface an enable low resistance by mainly containing grains with c-axis orientation in a WSix film. SOLUTION: A gate oxide film 2, a polycrystalline silicon film 3 and a WSix film (c-axis orientation WSix film) 4 mainly containing grains with c-axis orientation are laminated one by one in a gate electrode, and a cover film 5 formed of SiO2 is further formed on the WSix film 4. The ratio of Si constituting the WSix film 4 with respect to W (Si/W composition ratio) is 2.7 or less in composition ratio, and desirably about 2.0. That is, after the gate oxide film 2 and the polycrystalline silicon film 3 are formed one by one through a normal semiconductor process, the WSix film 4 is formed by sputtering and the cover film 5 formed of SiO2 is formed by a CVD method. Thereby, a WOx film is not formed by abnormal oxidation in the surface of the WSix film 4, and a flat WSix film 4 is formed.
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