Method for forming a semiconductor device having a metal gate recess
Provided are approaches of forming a semiconductor device (e.g., transistor such as a FinFET or planar device) having a gate metal recess. In one approach, a liner layer and a metal layer (e.g., W) are applied in a trench (e.g., via CVD and/or ALD). Then, a single chamber (e.g., an extreme fill chamber) will be utilized to separately etch back the liner layer and the metal layer. In general, the liner layer may be etched back further than the metal layer to provide for larger contact and lower resistance. After etching is complete, a bottom-up fill/growth of metal (e.g., W) will be performed (e.g., via CVD in a W chamber or the like) to increase the presence of gate metal in the trench.
1. A method of forming a semiconductor device having a metal gate recess, comprising:
forming a liner layer over a work function metal layer within a trench of the semiconductor device, the work function metal layer being formed over a high k-layer that is formed over a substrate;
forming a metal layer over the liner layer;
performing a first etch to etch at least a portion of the metal layer in the trench;
performing a second etch to etch at least a portion of the liner layer; and
performing a bottom-up fill of metal within the trench after the second etch to form the metal gate recess;
wherein the first etch and the second etch are performed in a single etch chamber.
2. The method of claim 1 , the liner layer comprising titanium nitride (TiN).
3. The method of claim 1 , the metal layer comprising tungsten (W).
4. The method of claim 1 , the bottom-up fill of metal comprising a bottom-up growth of W.
5. The method of claim 1 , the bottom-up fill of metal being performed using a chemical vapor deposition (CVD) W chamber.
6. The method of claim 1 , the liner layer being formed over a work function metal layer, and the work function metal layer being formed over a high-k layer.
7. The method of claim 1 , further comprising a semiconductor device formed by the method of claim 1 .
8. A method of forming a semiconductor device having a metal gate recess, comprising:
depositing a liner layer over a work function metal layer within a trench of the semiconductor device, the work function metal layer being formed over a high k-layer that is formed over a substrate;
depositing a tungsten (W) layer over the liner layer;
performing a first etch to etch at least a portion of the metal layer in the trench;
performing a second etch to etch at least a portion of the liner layer; and
performing a bottom-up growth of W within the trench after the second etch to form the metal gate recess;
wherein the first etch and the second etch are performed in a single etch chamber.
9. The method of claim 8 , the liner layer comprising titanium nitride (TiN).
10. The method of claim 8 , the metal layer comprising tungsten (W).
11. The method of claim 8 , the bottom-up growth of W being performed using a chemical vapor deposition (CVD) W chamber.
12. The method of claim 8 , the work function metal layer being deposited over a high-k layer.
13. The method of claim 8 , further comprising a semiconductor device formed by the method of claim 1 .