Methods for forming mixed metal oxide epitaxial films

Patent metadata

Field	Value
Publication number	US-2016138182-A1
Application number	US-201414546199-A
Country	US
Kind code	A1
Filing date	Nov 18, 2014
Priority date	Nov 18, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

Provided are methods for forming a mixed metal oxide epitaxial film (e.g., ScAlMgO 4 ) comprising growing an amorphous layer of a mixed metal oxide on a substrate (e.g., crystalline sapphire) via atomic layer deposition and annealing the amorphous layer of the mixed metal oxide at an elevated temperature for a period of time sufficient to induce epitaxial solid-state re-growth of the amorphous layer of the mixed metal oxide, thereby forming the mixed metal oxide epitaxial film. The method may further comprise growing a layer of a semiconductor (e.g., GaN) on the mixed metal oxide epitaxial film.

First claim

What is claimed is:

1 . A method for forming a mixed metal oxide epitaxial film, the method comprising:
growing an amorphous layer of a mixed metal oxide on a crystalline substrate via atomic layer deposition, and annealing the amorphous layer of the mixed metal oxide at an elevated temperature for a period of time sufficient to induce epitaxial solid-state re-growth of the amorphous layer of the mixed metal oxide, thereby forming the mixed metal oxide epitaxial film.

2 . The method of claim 1 , wherein the mixed metal oxide is a quaternary metal oxide.

3 . The method of claim 1 , wherein the mixed metal oxide is one which has an in-plane lattice mismatch with a III-V nitride semiconductor of no more than ±5% at room temperature.

4 . The method of claim 1 , wherein the mixed metal oxide has the formula ScAMO 4 , wherein A is a trivalent cation selected from Fe(III), Ga and Al and M is a divalent cation selected from Mg, Mn, Fe(II), Co, Cu, Zn and Cd.

5 . The method of claim 4 , wherein the mixed metal oxide is ScAlMgO 4 .

6 . The method of claim 1 , wherein the crystalline substrate is one which has an in-plane lattice mismatch with a III-V nitride semiconductor of at least ±6% at room temperature.

7 . The method of claim 1 , wherein the crystalline substrate is sapphire.

8 . The method of claim 1 , wherein the mixed metal oxide is ScAlMgO 4 and the crystalline substrate is sapphire.

9 . The method of claim 1 , further comprising growing a layer of a semiconductor on the mixed metal oxide epitaxial film.

10 . The method of claim 9 , wherein the in-plane lattice mismatch between the crystalline substrate and the semiconductor is at least ±6% at room temperature and the in-plane lattice mismatch between the semiconductor and the mixed metal oxide is no more than ±5% at room temperature.

11 . The method of claim 10 , wherein the crystalline substrate is sapphire.

12 . The method of claim 11 , wherein the semiconductor is a III-V nitride semiconductor.

13 . The method of claim 12 , wherein the mixed metal oxide has the formula ScAMO 4 , wherein A is a trivalent cation selected from Fe(III), Ga and Al and M is a divalent cation selected from Mg, Mn, Fe(II), Co, Cu, Zn and Cd.

14 . The method of claim 13 , wherein the mixed metal oxide is ScAlMgO 4 and the III-V nitride semiconductor is GaN.

15 . A multilayer structure comprising:
a crystalline substrate, a quaternary metal oxide epitaxial film on the surface of the crystalline substrate, the quaternary metal oxide composed of oxide anions, cations of a first metal, cations of a second metal and cations of a third metal, and a layer of a semiconductor on the surface of the quaternary metal oxide epitaxial film, wherein the quaternary metal oxide epitaxial film is single-phase and is substantially free of metal cations other than the cations of the first metal, the cations of the second metal and the cations of the third metal.

16 . The multilayer structure of claim 15 , wherein the quaternary metal oxide is one which has an in-plane lattice mismatch with a III-V nitride semiconductor of no more than ±5% at room temperature.

17 . The multilayer structure of claim 15 , wherein the quaternary metal oxide has the formula ScAMO 4 , wherein A is a trivalent cation selected from Fe(III), Ga and Al and M is a divalent cation selected from Mg, Mn, Fe(II), Co, Cu, Zn and Cd.

18 . The multilayer structure of claim 17 , wherein the quaternary metal oxide is ScAlMgO 4 .

19 . The multilayer structure of claim 17 , wherein the crystalline substrate is sapphire and the semiconductor is a III-V nitride semiconductor.

20 . The multilayer structure of claim 19 , wherein the quaternary metal oxide is ScAlMgO 4 and the III-V nitride semiconductor is GaN.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Kuech Thomas F

Classifications

• H10P14/3416

  Nitrides · CPC title

• H10P14/3238

  being insulating materials · CPC title

• C30B29/26

  with formula BMe2O4, wherein B is Mg, Ni, Co, Al, Zn, or Cd and Me is Fe, Ga, Sc, Cr, Co, or Al · CPC title

• C30B1/023 Primary

  from solids with amorphous structure · CPC title

• C30B25/186

  being specially pre-treated by, e.g. chemical or physical means · CPC title