Method for manufacturing a layer of gallium nitride or gallium and aluminum nitride
View Patent ↗The present invention relates to a crack-free monocrystalline nitride layer having the composition AlxGa 1−x N, where 0≦x≦0.3, and a substrate that is likely to generate tensile stress in the nitride layer. The structure successively includes the substrate; a nucleation layer; a monocrystalline intermediate layer having a selected thickness on the nucleation layer; a monocrystalline seed layer of an AlBN compound in which the boron content is between 0 and 10% having a selected thickness on the intermediate layer and a relaxation rate, at ambient temperature, of less than 80%; and the monocrystalline nitride layer.
1. A structure comprising a crack-free monocrystalline nitride layer having the composition AlxGa 1−x N, where 0≦x≦0.3, and a substrate that is likely to generate tensile stress in the nitride layer, the structure successively comprising:
the substrate;
a nucleation layer;
a monocrystalline intermediate layer having a selected thickness on the nucleation layer;
a monocrystalline seed layer of an AlBN compound in which the boron content is between 0 and 10% having a selected thickness on the intermediate layer and a relaxation rate, at ambient temperature, of less than 80%; and
the monocrystalline nitride layer.
2. The structure according to claim 1 , wherein the seed and intermediate layers are present at a thickness ratio of between 0.05 and 1.
3. The structure according to claim 1 , wherein the seed and intermediate layers are present at a thickness ratio of between 0.2 and 0.35.
4. The structure according to claim 1 , wherein the monocrystalline nitride layer has a thickness of between 800 nm and 7 micrometers.
5. The structure according to claim 1 , wherein the intermediate layer is aluminum or gallium nitride.
6. The structure according to claim 1 , wherein the intermediate layer is aluminum nitride having an aluminum content of between 1 and 35%.
7. The structure according to claim 1 , wherein the intermediate layer has a thickness that is equal to or greater than 250 nm.
8. The structure according to claim 1 , wherein the seed layer has a thickness of between 30 and 250 nm.
9. The structure according to claim 1 , wherein the seed layer has a relaxation rate at ambient temperature of between 50 and 75%.
10. The structure according to claim 1 , wherein the monocrystalline nitride layer comprises 3 to 5% of aluminum and wherein the structure further successively comprises, on the monocrystallilne nitride layer:
a gallium nitride channel layer; and
a barrier layer of AlGaN, AlInN or BGaN.
11. The structure according to claim 10 , wherein the gallium nitride channel layer has a thickness of 5 to 100 nm.
12. The structure according to claim 1 , wherein the structure further successively comprises, on the monocrystalline nitride layer:
a channel layer of ScN; and
a barrier layer of AlGaN, AlInN or BGaN.
13. The structure according to claim 1 , wherein the monocrystalline nitride layer is gallium nitride and wherein the structure further comprises, on the gallium nitride layer, a barrier layer of AlGaN, AlInN or BGaN.
14. A device comprising the structure of claim 1 and provided in the form of a photovoltaic component, an electroluminescent diode, a Schottky diode, a laser, an optical detector, or an MEMS.
15. A field effect transistor comprising the structure of claim 1 .