METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE HAVING METAL GATE

摘要

The present invention provides a method for forming a semiconductor device having a metal gate. The method includes firstly, a substrate is provided, and a first semiconductor device and a second semiconductor device are formed on the substrate, having a first gate trench and a second trench respectively. Next, a bottom barrier layer is formed in the first gate trench and a second trench. Afterwards, a first pull back step is performed, to remove parts of the bottom barrier layer, and a first work function metal layer is then formed in the first gate trench. Next, a second pull back step is performed, to remove parts of the first work function metal layer, wherein the topmost portion of the first work function metal layer is lower than the openings of the first gate trench and the second gate trench.

主权项

1. A method for forming a semiconductor device having a metal gate, comprising the following steps:
providing a substrate, a first semiconductor device and a second semiconductor device being formed on the substrate, having a first gate trench and a second trench respectively; forming a bottom barrier layer in the first gate trench and the second trench; performing a first pull back step, to remove parts of the bottom barrier layer, and to form a U-shaped bottom barrier layer; forming a first work function metal layer in the first gate trench; performing a second pull back step, to remove parts of the first work function metal layer, wherein the topmost portion of the first work function metal layer is lower than the opening of the first gate trench; and forming a second work function metal layer in the first gate trench and in the second trench, wherein the topmost portion of the second work function metal layer, the opening of the first gate trench and the opening of the second trench are on the same level.