| 摘要 |
PURPOSE:To form an electrode onto a shallow impurity diffusion region in low concentration, and to obtain a semiconductor device having LDD structure capable of stably maintaining characteristics by selectively depositing high melting-point metallic films onto the top face and side face of a gate electrode consisting of polysilicon. CONSTITUTION:The surface of a P-type silicon substrate 11 is thermally oxidized to shape a gate oxide film 12, and a polysilicon film 13 is deposited onto the oxide film 12 through a decompression CVD method. Arsenic ions are implanted, using the etched polysilicon film 13 as a mask to form an N<-> region 14. A W film 15 is deposited under decompression by employing the mixed gas of WF6 and H2. The W film 15 is deposited only onto the top face and side face of the film 13 through selective CVD at that time. Arsenic ions are implanted again, using the film 15 as a mask to shape an N<+> region 16. The surface of the W film 15 is exposed to a nitrogen atmosphere to form a tungsten nitride film 18. A thick gate oxide film 19 is shaped onto the N<+> and N<-> regions through oxidation in an oxidizing atmosphere, and the thickness of the oxide film in an edge region in the gate insulating film is also thickened. A wiring is formed, and a protective film is deposited.
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