| 摘要 |
PURPOSE: A method for fabricating a gate of a semiconductor device is provided to prevent dishing from being generated in a process for forming a metal gate by forming a dual gate of polysilicon and metal. CONSTITUTION: The first oxide layer(22), the first nitride layer(23) and the second oxide layer are sequentially formed on a silicon substrate(21). The second oxide layer, the first nitride layer and the first oxide layer are patterned to form a trench so that the substrate is exposed. A gate oxide layer(26) is formed on the second oxide layer and the trench. A polysilicon layer(27) is formed on the gate oxide layer. A metal layer(28) having such a thickness as to completely fill the trench is formed on the polysilicon layer. The gate oxide layer, the polysilicon layer and the metal layer are polished to expose the second oxide layer and the gate oxide layer, the polysilicon layer and the metal layer inside the trench. The first oxide layer is etched to expose the polysilicon layer on both sidewalls of the trench, the first nitride layer of the substrate and the surface of the gate oxide layer so that a gate(30) is formed on the substrate. A buffer oxide layer and the second nitride layer are sequentially formed to cover the gate electrode. The second nitride layer, the buffer oxide layer and the first oxide layer at both sides of the gate electrode are etched to form a spacer(33) on both sidewalls of the gate electrode.
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