| 摘要 |
PURPOSE: A gate electrode formation method in semiconductor device is provided to be capable of forming a gate bird's beak while preventing expansion of a tungsten film, by precluding a spacer for prevention of oxidization. CONSTITUTION: A gate electrode formation method includes sequentially depositing a gate oxide film(11), a polysilicon film(12), a metal barrier film(13), a tungsten film(14) and a hard mask film(15) on a semiconductor substrate(10). They are then patterned to form a gate electrode. An oxidization prevention film is formed on the resulting structure. The oxidization prevention film is etched by reactive ion etch process, thus forming a spacer for oxidization prevention(16) blocking the sidewall of the gate electrode. The entire results is oxidized. Thus, expansion of the tungsten film is prevented by the spacer for oxidization prevention and the gate oxide film grown in the semiconductor substrate is also grown through the bottom of the spacer for oxidization prevention, thus forming a bird's beak.
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