| 摘要 |
PURPOSE: A method for forming a gate electrode in a semiconductor device is provided to prevent damage of a gate polysilicon layer and loss of silicon by using a buffer oxide layer and a buffer polysilicon layer. CONSTITUTION: A gate oxide layer(20) and a gate polysilicon layer(30) are sequentially formed on a silicon substrate(10). An n+ and p+ polysilicon region are formed by selectively implanting dopants into the gate polysilicon layer(30). A buffer oxide layer(70) and a buffer polysilicon layer(80) are sequentially formed on the resultant structure. A mask pattern(40) is formed on the buffer polysilicon layer to expose a gate formation region. A tungsten film(60) is formed on the exposed buffer polysilicon layer by selective epitaxial growth. After removing the mask pattern(40), the buffer polysilicon layer, the buffer oxide layer, the gate polysilicon layer and the gate oxide layer are sequentially etched using the tungsten film(60) as a mask. Then, the tungsten film(60), the buffer polysilicon layer(80) and the buffer oxide layer(70) are removed.
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