GeSOI transistor with low junction current and low junction capacitance and method for making the same
A semiconductor device ( 101 ) is provided herein which comprises a substrate ( 103 ) comprising germanium. The substrate has source ( 107 ) and drain ( 109 ) regions defined therein. A barrier layer ( 111 ) comprising a first material that has a higher bandgap (E g ) than germanium is disposed at the boundary of at least one of said source and drain regions. At least one of the source and drain regions comprises germanium.
1. A semiconductor device, comprising:
a semiconductor layer comprising germanium and having source and drain regions defined therein; and
a barrier layer disposed along the bottom of at least one of said source and drain regions, said barrier layer comprising a first material that has a higher bandgap (E g ) than germanium;
wherein at least one of said source and drain regions contains a second material that comprises germanium;
wherein the bandgap (E g ) of said first material is at least about 1.1 eV.
2. The semiconductor device of claim 1 , wherein said first material is selected from the group consisting of Si, SiGe, SiGeC, GeC and SiC.
3. The semiconductor device of claim 1 , wherein said first material is GeC and contains at least 2% carbon by weight, based on the total weight of the first material.
4. The semiconductor device of claim 1 , wherein said second material comprises a material selected from the group consisting of Ge, SiGe, and SiGeC.
5. The semiconductor device of claim 1 , wherein said first material has a lower dielectric constant than germanium.
6. The semiconductor device of claim 1 , wherein said semiconductor device is a Germanium-On-Insulator (GeOI) substrate.
7. The semiconductor device of claim 1 , wherein said barrier layer is formed in both of the source and drain regions.
8. The semiconductor device of claim 1 , wherein both of said source and drain regions contain a second material that comprises germanium.
9. The semiconductor device of claim 1 , wherein the dielectric constant of said first material is less than about 11.
10. A semiconductor device, comprising:
a semiconductor layer comprising germanium and having source and drain regions defined therein; and
a barrier layer disposed at the boundary between at least one of said source and drain regions and said semiconductor layer, said barrier layer comprising a first material that has a higher bandgap (E g ) than germanium and a dielectric constant of less than about 11;
wherein at least one of said source and drain regions contains a second material that comprises germanium.
11. The semiconductor device of claim 10 , wherein said first material is selected from the group consisting of Si, SiGe, SiGeC, GeC and SiC.
12. The semiconductor device of claim 10 , wherein said first material is GeC and contains at least 2% carbon by weight, based on the total weight of the first material.
13. The semiconductor device of claim 10 , wherein said second material comprises a material selected from the group consisting of Ge, SiGe, and SiGeC.
14. A semiconductor device, comprising:
a semiconductor layer comprising germanium and having source and drain regions defined therein, wherein at least one of said source and drain regions contains a second material that comprises germanium; and
a barrier layer disposed at the boundary between at least one of said source and drain regions and said semiconductor layer, said barrier layer comprising GeC and containing at least 2% carbon by weight, based on the total weight of the first material.
15. The semiconductor device of claim 14 , wherein said first material has a higher bandgap (E g ) than germanium.
16. The semiconductor device of claim 14 , wherein said second material comprises a material selected from the group consisting of Ge, SiGe, and SiGeC.
17. The semiconductor device of claim 14 , wherein said first material has a lower dielectric constant than germanium.
18. The semiconductor device of claim 14 , wherein the dielectric constant of said first material is less than about 11.
19. The semiconductor device of claim 14 , wherein said barrier layer is disposed at the boundary between each of said source and drain regions.