Parasitic channel mitigation using elemental diboride diffusion barrier regions
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 silicon substrate and comprising at least a layer having a resistivity of greater than 10 2 Ohms-cm;
a diffusion barrier region comprising an elemental diboride located over a surface of the substrate; and
a III-nitride material region located over the diffusion barrier region.
2. The semiconductor structure of claim 1 , wherein the peak of the sum of the concentrations of Group III species in the substrate is less than about 10 17 /cm 3 .
3. The semiconductor structure of claim 1 , wherein the peak of the sum of the concentrations of Al, Ga, and In in the substrate is less than about 10 17 /cm.
4. The semiconductor structure of claim 1 , wherein the peak concentration of Al, Ga, and/or In in the substrate is less than about 10 17 /cm 3 .
5. The semiconductor structure of claim 1 , wherein the substrate comprises a surface region associated with the surface of the substrate, and the surface region comprises a low-conductivity parasitic channel or the substrate is free of a parasitic channel.
6. The semiconductor structure of claim 1 , wherein the substrate is a bulk silicon wafer.
7. The semiconductor structure of claim 1 , wherein the substrate is a silicon-on-insulator 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 semiconductor structure comprises a transistor located over the substrate.
10. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride nucleation layer.
11. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride transition layer.
12. The semiconductor structure of claim 11 , wherein the III-nitride transition layer is compositionally graded.
13. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride buffer layer.
14. The semiconductor structure of claim 1 , wherein the III-nitride material region comprises a III-nitride device region.
15. The semiconductor structure of claim 1 , wherein the elemental diboride comprises zirconium diboride, aluminum diboride, hafnium diboride and/or one or more alloys of these.
16. A semiconductor structure, comprising:
a substrate comprising silicon and comprising at least a layer having a resistivity of greater than 10 2 Ohms-cm;
a diffusion barrier region comprising an elemental diboride located over a surface of the substrate; and
a III-nitride material region located over the diffusion barrier region,
wherein the substrate comprises a surface region associated with the surface of the substrate, and the surface region comprises a low-conductivity parasitic channel or the substrate is free of a parasitic channel,
wherein the low-conductivity parasitic channel has a peak free carrier concentration that is less than about 10 17 /cm 3 .
17. The semiconductor structure of claim 16 , wherein the low-conductivity parasitic channel has a total integrated surface region charge of less than about 10 12 /cm 2 .
18. The semiconductor structure of claim 16 , wherein the substrate is a silicon carbide substrate.
19. A method of forming a semiconductor structure, comprising:
forming a diffusion barrier region comprising an elemental diboride over a silicon substrate, the substrate comprising at least a layer having a resistivity of greater than 10 2 Ohms-cm; and
forming a III-nitride material region over the diffusion barrier region.