High quality vanadium dioxide films

Patent metadata

Field	Value
Publication number	US-9972687-B1
Application number	US-201715464536-A
Country	US
Kind code	B1
Filing date	Mar 21, 2017
Priority date	Dec 18, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

Layers of high quality VO 2 and methods of fabricating the layers of VO 2 are provided. The layers are composed of a plurality of connected crystalline VO 2 domains having the same crystal structure and the same epitaxial orientation.

First claim

What is claimed is:

1. A layer of VO 2 comprising a plurality of connected crystalline VO 2 domains having the same crystal structure and the same epitaxial orientation, wherein the layer of VO 2 is a continuous layer in which the crystalline VO 2 domains in the plurality of connected crystalline VO 2 domains are in direct contact with other crystalline VO 2 domains in the plurality of crystalline VO 2 domains.

2. The layer of VO 2 of claim 1 , wherein the layer is crack free.

3. The layer of VO 2 of claim 1 , wherein the layer is strain free.

4. The layer of VO 2 of claim 1 , having a layer thickness of at least 100 nm.

5. The layer of VO 2 of claim 4 , having a layer thickness in the range from 100 nm to 500 nm.

6. The layer of VO 2 of claim 4 , wherein any cracks present in the layer are confined to within 10 nm or fewer of one surface of the layer.

7. The layer of VO 2 of claim 4 , wherein any strain present in the layer is confined to within 10 nm or fewer of one surface of the layer.

8. The layer of VO 2 of claim 4 , wherein the crystalline VO 2 domains have an average width of no greater than 500 nm and any cracks present in the layer are confined to within 5 nm or fewer of one surface of the layer.

9. The layer of VO 2 of claim 1 , wherein the crystalline VO 2 domains have an average width of no greater than 500 nm.

10. The layer of VO 2 of claim 1 , wherein the crystalline VO 2 domains have an average width of no greater than 300 nm.

11. The layer of VO 2 of claim 1 , wherein the VO 2 has a metal-insulator phase transition critical temperature, below which the VO 2 has a monoclinic crystal structure and above which the VO 2 has a rutile crystal structure, the layer of VO 2 being characterized in that, when it is heated from a temperature below its metal-insulator phase transition critical temperature to a temperature above its metal-insulator phase transition critical temperature, the VO 2 undergoes the phase transition from monoclinic to rutile with a transition sharpness of no greater than 2 K.

12. The layer of VO 2 of claim 11 , wherein the VO 2 has a metal-insulator phase transition critical temperature, below which the VO 2 has a monoclinic crystal structure and above which the VO 2 has a rutile crystal structure, the layer of VO 2 being characterized in that, when it is heated from a temperature below its metal-insulator phase transition critical temperature to a temperature above its metal-insulator phase transition critical temperature, the VO 2 undergoes a phase transition from monoclinic to rutile and the electrical resistance of the layer of VO 2 decreases by at least four orders of magnitude.

13. The layer of VO 2 of claim 1 , wherein the VO 2 has a metal-insulator phase transition critical temperature, below which the VO 2 has a monoclinic crystal structure and above which the VO 2 has a rutile crystal structure, the layer of VO 2 being characterized in that, when it is heated from a temperature below its metal-insulator phase transition critical temperature to a temperature above its metal-insulator phase transition critical temperature, the VO 2 undergoes the phase transition from monoclinic to rutile with a transition sharpness of no greater than 1 K.

14. The layer of VO 2 of claim 1 , wherein the VO 2 has a metal-insulator phase transition critical temperature, below which the VO 2 has a monoclinic crystal structure and above which the VO 2 has a rutile crystal structure, the layer of VO 2 being characterized in that, when it is heated from a temperature below its metal-insulator phase transition critical temperature to a temperature above its metal-insulator phase transition critical temperature, the VO 2 undergoes a phase transition from monoclinic to rutile and the electrical resistance of the layer of VO 2 decreases by at least four orders of magnitude.

15. The layer of VO 2 of claim 1 , wherein the layer overlies a template layer with which the VO 2 has a lattice mismatch.

16. The layer of VO 2 of claim 1 , wherein layer of VO 2 overlies a layer of columnar, crystalline domains of rutile SnO 2 .

17. The layer of VO 2 of claim 1 , wherein the plurality of connected crystalline VO 2 domains includes crystalline VO 2 domains having different rotational orientations.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Eom Chang-Beom
• Lee Daesu

Classifications

• H10P14/3234

  being oxide semiconducting materials (Group IIB-VIA semiconductors H10P14/3224) · CPC title

• H10P14/2918

  being semiconductor metal oxides (Group IIB-VIA materials H10P14/2913) · CPC title

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• H10P14/3256

  Microstructure · CPC title

• H10P14/3238 Primary

  being insulating materials · CPC title