VERTICAL ALUMINUM GALLIUM NITRIDE DEVICES ON CRYSTALLINE METALLIC SUBSTRATES
Described herein are systems and methods for the facile growth of aluminum gallium nitride semiconductor devices by utilizing specific lattice matched substrates. These substrates include metal borides, for example, ScB 2 , HfB 2 and ZrB 2 and metal carbides and metal nitrides. These substrates may allow for the cost effective manufacturing of ultra-wide bandgap semiconductor devices.
1 . A device comprising:
a semiconducting material comprising Al x Ga 1-x N where 0<x<1;
a substrate having the formula MB 2 , wherein B is Boron and M is a metal comprising at least one of the group of Zr, Hf, Sc, Nb, Ta, Ti, V, Cr, Mn, Y, Mo, Mg, Al and U.
2 . A device comprising:
a semiconducting material comprising Al x X 1-x N where 0<x<1; wherein X comprises at least one of the group of Ga, In, Sc, Gd, or a combination thereof; and
a substrate having the formula MB 2 , wherein B is Boron and M is a metal comprising at least one of the group of Zr, Hf, Sc, Nb, Ta, Ti, V, Cr, Mn, Y, Mo, Mg, Al and U.
3 . The device of claim 1 , wherein the substrate is selected from the group of ScB 2 , HfB 2 and ZrB 2 .
4 . The device claim 1 , wherein the semiconducting material is lattice matched along an in-plane direction (a-direction) to the substrate; wherein the substrate has a lattice mismatch less than or equal to 1% for AlGaN.
5 . The device of claim 1 , wherein the AlGaN has an Al mole fraction greater than or equal to 0.4.
6 . The device of claim 1 , wherein the semiconducting material has an Al mole fraction greater than or equal to 0.5.
7 . The device of claim 1 , wherein the substrate exhibits metallic or semimetallic electron transport and the substrate has a resistance less than or equal to 0.0001 Ωcm.
8 . The device of claim 1 , wherein the semiconducting material has a vertical thickness greater than or equal to 1 μm.
9 . The device of claim 1 , wherein the device contains an ultra-wide bandgap semiconductor.
10 . The device of claim 1 , wherein the device has a vertical or pseudo-vertical orientation.
11 . The device of claim 1 , wherein the substrate is removable.
12 . The device of claim 11 , wherein the substrate is a thin film capable of removal via liftoff.
13 . The device of claim 11 , wherein the substrate is a bulk substrate.
14 . The device of claim 13 , wherein the substrate is acid soluble.
15 . The device of claim 15 , wherein the substrate is soluble in HF, HNO 3 or a combination thereof.
16 . A method comprising:
providing a single orientation crystal epitaxial substrate having the formula MB 2 , wherein B is Boron and M is a metal selected from the group of Zr, Hf, Sc, Nb, Ta, Ti, V, Cr, Mn, Y, Mo, Mg, Al and U;
growing a Al x Ga 1-x N semiconductor layer on the substrate;
wherein the substrate is lattice matched to Al x Ga 1-x N.
17 . The method of claim 16 , wherein the Al x Ga 1-x N layer has an Al mole fraction greater than or equal to 0.4.
18 . The method of claim 16 , wherein the substrate is selected from the group of ScB 2 , HfB 2 and ZrB 2 .
19 . The method of claim 16 , further comprising:
removing the single orientation crystal epitaxial substrate from the Al x Ga 1-x N semiconductor layer.
20 . The method of claim 19 , wherein the step of removing the single orientation crystal epitaxial substrate is performed by exposing the substrate to an acid.