Semiconductor device having metal gate and manufacturing method thereof

摘要

A method for manufacturing a semiconductor device having metal gate includes following steps. A substrate having at least a first semiconductor device formed thereon is provided. The first semiconductor device includes a first gate trench formed therein. Next, an n-typed work function metal layer is formed in the first gate trench. After forming the n-typed work function metal layer, a nitridation process is performed to form a first protecting layer on the n-typed work function metal layer. After forming the first protecting layer, an oxidation process is performed to the first protecting layer to form a second protecting layer on the n-typed work function metal layer. Then, a gap filling metal layer is formed to fill up the first gate trench.

主权项

1. A method for manufacturing a semiconductor device having metal gate, comprising:
providing a substrate having at least a first semiconductor device formed thereon, and the first semiconductor device comprising a first gate trench formed therein; sequentially forming a bottom barrier layer, an etch stop layer, and a p-typed work function metal layer on the substrate; forming an n-typed work function metal layer in the first gate trench after forming the p-typed work function metal layer; performing a nitridation process to form a first protecting layer on the n-typed work function metal layer; performing an oxidation process to the first protecting layer to form a second protecting layer on the n-typed work function metal layer after the nitridation; and forming a gap-filling metal layer to fill up the first gate trench.