III-nitride semiconductor structures comprising low atomic mass species
III-nitride materials are generally described herein, including material structures comprising III-nitride material regions and silicon-containing substrates. Certain embodiments are related to gallium nitride materials and material structures comprising gallium nitride material regions and silicon-containing substrates.
1. A semiconductor structure, comprising:
a substrate comprising silicon; and
a III-nitride material region located over a surface region of the substrate, wherein:
the surface region of the substrate comprises a low-conductivity parasitic channel or the substrate is free of a parasitic channel, and
at least a region of the substrate comprises at least one species having a relative atomic mass of less than 5 at a concentration of at least about 10 19 /cm 3 .
2. The semiconductor structure of claim 1 , wherein at least a portion of the surface region of the substrate comprises at least one species having a relative atomic mass of less than 5 at a concentration of at least about 10 19 /cm 3 .
3. The semiconductor structure of claim 1 , wherein the substrate comprises at least a layer having a resistivity of greater than about 10 2 Ohms-cm.
4. The semiconductor structure of claim 1 , wherein the substrate is a silicon substrate.
5. The semiconductor structure of claim 4 , wherein the substrate is a bulk silicon wafer.
6. The semiconductor structure of claim 4 , wherein the substrate is a silicon-on-insulator substrate.
7. The semiconductor structure of claim 1 , wherein the substrate is a silicon carbide substrate.
8. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises GaN.
9. The semiconductor structure of claim 1 , wherein the species having a relative atomic mass of less than 5 comprises hydrogen and/or helium.
10. The semiconductor structure of claim 1 , wherein the surface region of the substrate comprises a low-conductivity parasitic channel.
11. The semiconductor structure of claim 10 , wherein the low-conductivity parasitic channel has a peak free carrier concentration that is less than about 10 17 /cm 3 .
12. The semiconductor structure of claim 10 , wherein the low-conductivity parasitic channel has a total integrated surface region charge of less than about 10 12 /cm 2 .
13. The semiconductor structure of claim 10 , wherein the substrate comprises a bulk region below the surface region, the bulk region having a lower peak free carrier concentration than the surface region.
14. The semiconductor structure of claim 13 , wherein the bulk region is doped with a first free carrier type and the surface region is doped with a second free carrier type.
15. The semiconductor structure of claim 13 , wherein the peak free carrier concentration in the bulk region is less than about 10 13 /cm 3 .
16. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride nucleation layer.
17. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride transition layer.
18. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride buffer layer.
19. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride device region.
20. The semiconductor structure of claim 1 , comprising a diffusion barrier region between the III-nitride material region and the substrate.