Epitaxial metal oxide as buffer for epitaxial III-V layers

Patent metadata

Field	Value
Publication number	US-10923345-B2
Application number	US-201716088032-A
Country	US
Kind code	B2
Filing date	Mar 16, 2017
Priority date	Mar 23, 2016
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Systems and methods are described herein for growing epitaxial metal oxide as buffer for epitaxial III-V layers. A layer structure includes a base layer and a first rare earth oxide layer epitaxially grown over the base layer. The first rare earth oxide layer includes a first rare earth element and oxygen, and has a bixbyite crystal structure. The layer structure also includes a metal oxide layer epitaxially grown directly over the first rare earth oxide layer. The metal oxide layer includes a first cation element selected from Group III and oxygen, and has a bixbyite crystal structure.

First claim

What is claimed is:

1. A layer structure, comprising:
a base layer;
a first rare earth oxide layer epitaxially grown over the base layer, comprising:
a first rare earth element, and
oxygen,

wherein the first rare earth oxide layer has a bixbyite crystal structure; and
a metal oxide layer epitaxially grown directly over the first rare earth oxide layer, comprising:
a first cation element selected from Group III,

a second cation element selected from Group III or Group IV, and
oxygen,

wherein:
the metal oxide layer comprises a first region of the metal oxide layer adjacent to the first rare earth oxide layer and a second region of the metal oxide layer adjacent to a top surface of the metal oxide layer; and
a concentration of the second cation element varies from approximately zero at the first region to a maximum at the second region in a graded or stepwise manner, and
the metal oxide layer has a bixbyite crystal structure.

2. The layer structure of claim 1 , wherein the first rare earth oxide layer further comprises a second rare earth element.

3. The layer structure of claim 1 , further comprising a III-nitride layer epitaxially grown over the metal oxide layer.

4. The layer structure of claim 1 , further comprising a second rare earth oxide layer between the first rare earth oxide layer and the base layer.

5. The layer structure of claim 1 , wherein the metal oxide layer includes a transition in crystal structure from bixbyite to a second crystal structure.

6. The layer structure of claim 1 , further comprising:
a second rare earth oxide layer epitaxially grown over the metal oxide layer, comprising:
the first rare earth element, and
oxygen,
wherein the second rare earth oxide layer has a bixbyite crystal structure; and
a second metal oxide layer epitaxially grown directly over the second rare earth oxide layer, comprising:
the first cation element, and
oxygen,

wherein the second metal oxide layer has a bixbyite crystal structure.

7. A layer structure, comprising:
a base layer;
a first rare earth oxide layer epitaxially grown over the base layer and having a composition of (RE1 x RE2 1-x ) a O b (0≤x≤1; 1≤a≤3; 2≤b≤4), wherein RE1 and RE2 respectively represent a first rare earth element and a second rare earth element; and
a metal oxide layer epitaxially grown directly over the first rare earth oxide layer, comprising:
a first cation element selected from Group III or Group IV;

a second cation element selected from Group III or Group IV; and
oxygen,

wherein:
the metal oxide layer comprises a first region of the metal oxide layer adjacent to the first rare earth oxide layer and a second region of the metal oxide layer adjacent to a top surface of the metal oxide layer; and
a concentration of the second cation element varies from approximately zero at the first region to a maximum at the second region in a graded or stepwise manner, and
the metal oxide layer does not contain nitrogen.

8. The layer structure of claim 7 , further comprising a III-nitride layer epitaxially grown over the metal oxide layer.

9. The layer structure of claim 7 , further comprising a second rare earth oxide layer between the first rare earth oxide layer and the base layer.

10. The layer structure of claim 7 , wherein the metal oxide layer includes a transition in crystal structure from bixbyite to a second crystal structure.

11. The layer structure of claim 7 , further comprising:
a second rare earth oxide layer epitaxially grown over the metal oxide layer, comprising:
the first rare earth element, and
oxygen,

wherein the second rare earth oxide layer has a bixbyite crystal structure; and
a second metal oxide layer epitaxially grown directly over the second rare earth oxide layer, comprising:
the first cation element, and
oxygen,

wherein the second metal oxide layer has a bixbyite crystal structure.

12. The layer structure of claim 11 , wherein the second rare earth oxide layer further comprises the second rare earth element.

13. The layer structure of claim 11 , further comprising a III-nitride layer epitaxially grown over the second metal oxide layer.

14. The layer structure of claim 6 , wherein the second rare earth oxide layer further comprises the second rare earth element.

15. The layer structure of claim 6 , further comprising a III-nitride layer epitaxially grown over the second metal oxide layer.

Assignees

• Iqe Plc

Inventors

• Dargis Rytis
• Clark Andrew
• Pelzel Rodney

Classifications

• H10P14/3416

  Nitrides · CPC title

• H10P14/2905

  Silicon, silicon germanium or germanium · CPC title

• H10P14/3251 Primary

  consisting of three or more layers · CPC title

• H10P14/3238

  being insulating materials · CPC title

• H10P14/3254

  Graded layers · CPC title