Semiconductor structure having fluoride metal layer and process thereof
A semiconductor structure includes a substrate, a dielectric layer and a fluoride metal layer. The dielectric layer is located on the substrate. The fluoride metal layer is located on the dielectric layer. Furthermore, the present invention also provides a semiconductor process to form said semiconductor structure.
1. A semiconductor structure, comprising:
a substrate;
a dielectric layer located on the substrate;
a fluoride metal layer located on the dielectric layer; and
a fluoride metal gate layer located on and directly contacting the fluoride metal layer.
2. The semiconductor structure according to claim 1 , wherein the dielectric layer comprises a dielectric layer having a high dielectric constant.
3. The semiconductor structure according to claim 2 , wherein the dielectric layer having a high dielectric constant further comprises a hafnium oxide (HfO2) layer.
4. The semiconductor structure according to claim 1 , wherein the dielectric layer having a high dielectric constant comprises a fluoride dielectric layer having a high dielectric constant.
5. The semiconductor structure according to claim 1 , wherein the fluoride metal layer comprises a fluoride work function metal layer.
6. The semiconductor structure according to claim 1 , wherein the fluoride metal layer comprises a fluoride titanium nitride layer.
7. The semiconductor structure according to claim 1 , wherein a work function value of the semiconductor structure is between 4.9 eV and 5.1 eV.
8. The semiconductor structure according to claim 1 , wherein the semiconductor structure comprises a PMOS transistor.
9. A semiconductor process, comprising:
providing a substrate;
forming a dielectric layer on the substrate;
forming a fluoride metal layer on the dielectric layer, wherein the fluoride metal layer is formed by an atomic layer deposition (ALD) process with a precursor of fluoride comprising titanium tetrafluoride (TiF4); and
forming a fluoride metal gate layer directly on the fluoride metal layer.
10. The semiconductor process according to claim 9 , wherein the dielectric layer comprises a dielectric layer having a high dielectric constant.
11. The semiconductor process according to claim 9 , wherein the fluoride metal layer comprises a fluoride work function metal layer.
12. The semiconductor process according to claim 9 , wherein the fluoride metal layer comprises a fluoride titanium nitride layer.
13. The semiconductor process according to claim 9 , wherein forming the fluoride metal layer comprises:
forming a metal layer on the dielectric layer; and
doping the metal layer with fluoride ions to form the fluoride metal layer.
14. The semiconductor process according to claim 9 , wherein a barrier layer is formed on the dielectric layer after the dielectric layer is formed.
15. The semiconductor structure according to claim 1 , further comprising a barrier layer comprising a fluoride tantalum nitride layer located between the dielectric layer and the fluoride metal layer.
16. The semiconductor structure according to claim 1 , wherein the dielectric layer comprises a hafnium silicon oxynitride (HfSiON) layer.
17. The semiconductor structure according to claim 1 , wherein the fluoride metal layer has a U-shaped cross-sectional profile.