| 摘要 |
PROBLEM TO BE SOLVED: To provide a gate electrode forming method of a semiconductor element for suppressing oxidation of a flame-resistant metallic film, such as a tungsten film and for preventing the deformation of a gate electrode, in a reoxidation process. SOLUTION: A gate insulating film 21, a doped polysilicon film and a sacrificial film are sequentially formed on a semiconductor substrate 20. The sacrificial film pattern in the form of a gate electrode and a polysilicon film pattern 22a are formed. A reoxidized film 24 is formed on the sidewall of the polysilicon film pattern 22a. An insulating film spacer 25 is formed in a sacrificial film pattern and the sidewall of the reoxidized film 24. When heavily doping impurity ions are implanted in substrates on both sides of the spacer 225, an interlayer insulating film 26 is formed. The sacrificial pattern is removed, and a trench is formed. Then, a barrier metallic film 28 is formed on the surface of the trench. A flame-resistant metallic film 29 is formed so that it is buried in the trench. A gate electrode 300 formed of the polysilicon film pattern 22a, the barrier metallic film 28 and the flame-resistant metallic film 29 is formed.
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