Homoepitaxial gallium-nitride-based electronic devices and method for producing same
View Patent ↗There is provided an electronic device. The electronic device includes at least one epitaxial semiconductor layer disposed on a single crystal substrate comprised of gallium nitride having a dislocation density less than about 10 5 per cm 2 . A method of forming an electronic device is also provided. The method includes providing a single crystal substrate comprised of gallium nitride having a dislocation density less than about 10 5 per cm 2 , and homoepitaxially forming at least one semiconductor layer on the substrate.
1. A homoepitaxial gallium nitride based electronic device comprising:
at least one epitaxial semiconductor layer disposed on a single crystal substrate comprised of gallium nitride, the substrate having a dislocation density less than about 10 5 per cm 2 and being free of grain boundaries and of tilt boundaries, wherein the at least one semiconductor layer is included in the electronic device which comprises a transistor having source and drain contacts disposed over the substrate and a gate contact disposed between the source and drain contacts.
2. The electronic device of claim 1 , wherein the dislocation density is less than about 10 3 per cm 2 .
3. The electronic device of claim 1 , wherein the substrate has an oxygen impurity concentration of less than 3×10 18 cm −3 .
4. The electronic device of claim 3 , wherein the substrate has an oxygen impurity concentration of less than 3×10 17 cm −3 .
5. The electronic device of claim 1 , wherein the electronic device is a high-electron mobility transistor (HEMT), and the oxygen impurity concentration of the substrate is less than 3×10 18 cm 3 .
6. The electronic device of claim 5 , wherein the at least one semiconductor layer comprises a buffer layer disposed over the substrate.
7. The electronic device of claim 6 , wherein the buffer layer comprises undoped GaN.
8. The electronic device of claim 6 , wherein the at least one semiconductor layer further comprises a barrier layer formed over the buffer layer.
9. The electronic device of claim 8 , wherein the barrier layer comprises undoped AlInGaN.
10. The electronic device of claim 8 , wherein the barrier layer includes a top sub barrier layer and a bottom sub layer, wherein the bottom sub layer has a higher bandgap than the top sub barrier layer.
11. The electronic device of claim 10 , wherein the bottom sub barrier layer comprises AlN and the top sub barrier layer comprises AlGaN.
12. The electronic device of claim 5 , wherein the at least one semiconductor layer comprises a contact layer disposed over the substrate.
13. The electronic device of claim 12 , wherein the contact layer comprises n-doped GaN.
14. A homoepitaxial gallium nitride based electronic device consisting essentially of:
at least one epitaxial semiconductor layer disposed on a single crystal substrate comprised of gallium nitride, the substrate having a dislocation density less than about 10 5 per cm 2 , wherein the at least one semiconductor layer is included in the electronic device which comprises one of a transistor having source and drain contacts disposed over the substrate and a gate contact disposed between the source and drain contacts.
15. The electronic device of claim 14 , wherein the dislocation density is less than about 10 3 per cm 2 .
16. The electronic device of claim 14 , wherein the substrate has an oxygen impurity concentration of less than 3×10 18 cm −3 .
17. The electronic device of claim 16 , wherein the substrate has an oxygen impurity concentration of less than 3×10 17 cm −3 .
18. The electronic device of claim 14 , wherein the electronic device is a high-electron mobility transistor (HEMT), and the oxygen impurity concentration of the substrate is less than 3×10 18 cm 3 .