LOW-LOSS SUPERCONDUCTING DEVICES

• US 20130029848A1
• Filed: 07/28/2011
• Published: 01/31/2013
• Est. Priority Date: 07/28/2011
• Status: Active Grant

• Current Assignee: National Institute of Standards and Technology (Government of the United States of America), International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Keefe, George A., Pappas, David P., Rothwell, Mary E., Steffen, Matthias, Tsuei, Chang C., Gonzalez, Antonio D. Corcoles, Gao, Jiansong, Hite, Dustin A., Vissers, Michael R., Wisbey, David S.
• Granted Patent: US 8,954,125 B2
• Time in Patent Office: Days
• US Class Current: 505/210
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G06N 10/00 Quantum computing, i.e. information processing based on quantum-mechanical phenomena
• CPC Class Codes: H01P 1/201 Filters for transverse electromagnetic waves H01P1/212, H01P1/213, H01P1/215, H01P1/219 take precedence
• CPC Class Codes: H01P 1/2013 Coplanar line filters
• CPC Class Codes: H01P 3/003 Coplanar lines
• CPC Class Codes: H01P 3/026 Coplanar striplines [CPS]
• CPC Class Codes: H10N 60/0241 of devices comprising nitrides or carbonitrides
• CPC Class Codes: H10N 60/12 Josephson-effect devices
• CPC Class Codes: H10N 60/20 Permanent superconducting devices
• CPC Class Codes: H10N 60/85 Superconducting active materials
• CPC Class Codes: H10N 69/00 Integrated devices, or assemblies of multiple devices, comprising at least one superconducting element covered by group H10N60/00

Abstract

Low-loss superconducting devices and methods for fabricating low loss superconducting devices. For example, superconducting devices, such as superconducting resonator devices, are formed with a (200)-oriented texture titanium nitride (TiN) layer to provide high Q, low loss resonator structures particularly suitable for application to radio-frequency (RF) and/or microwave superconducting resonators, such as coplanar waveguide superconducting resonators. In one aspect, a method of forming a superconducting device includes foaming a silicon nitride (SiN) seed layer on a substrate, and forming a (200)-oriented texture titanium nitride (TiN) layer on the SiN seed layer.

Claims

1. A method of forming a superconducting device, comprising:

forming a silicon nitride (SiN) seed layer on a substrate; and

forming a (200)-oriented texture titanium nitride (TiN) layer on the SiN seed layer.

2. The method of claim 1, wherein the substrate is a silicon substrate, the method further comprising preparing the silicon substrate by removing native oxide from a surface of the silicon substrate and hydrogen terminating the surface of the silicon substrate.

3. The method of claim 1, wherein the substrate is a sapphire substrate, the method further comprising preparing the sapphire substrate by performing an in situ anneal to approximately 900°

C. in an oxygen atmosphere.

4. The method of claim 1, wherein forming a SiN seed layer comprises:

heating the substrate, comprising a silicon substrate, to a temperature of approximately 450°

C. to 500°

C.; and

soaking the heated silicon substrate in nitrogen gas sufficient to form a thin SiN layer of approximately 1 nm to 3 nm.

5. The method of claim 1, wherein the (200)-oriented texture TiN layer is formed by a reactive DC sputtering deposition process.

6. The method of claim 5, wherein the sputtering process is performed at a temperature of approximately 450°

C. to 500°

C.

7. The method of claim 5, wherein the sputtering process is performed by applying a DC bias of approximately −

100V on the substrate.

8. The method of claim 5, wherein the sputtering process is performed in a sputtering atmosphere of approximately 3:

2 argon to nitrogen ratio.

9. The method of claim 5, wherein the sputtering process is performed in a sputtering atmosphere at a pressure of approximately 5 mTorr.

10. The method of claim 5, wherein the (200)-oriented texture TiN layer is grown at a growth rate of approximately 1 nm to 2 nm per minute.

11. The method of claim 1, further comprising patterning the TiN and SiN layers to form a resonator device.

12. A superconducting device, comprising:

a substrate;

a silicon nitride (SiN) seed layer disposed over the substrate; and

a (200)-oriented texture titanium nitride (TiN) layer disposed over the SiN seed layer.

13. The superconducting device of claim 12, wherein the superconducting device comprises a resonator device.

14. The superconducting device of claim 13, wherein the resonator device comprises a coplanar waveguide.

15. The superconducting device of claim 13, wherein the resonator device comprises a qubit.

16. The superconducting device of claim 15, wherein the qubit comprises an interdigitated capacitor pattern formed by the SiN and (200)-oriented texture TiN layers.

17. The superconducting device of claim 13, wherein the resonator device comprises at least one planar capacitor and one planar inductor connected in parallel.

18. An integrated circuit, comprising:

a substrate; and

one or more superconducting devices formed on the substrate,

wherein each superconducting device comprises;

a silicon nitride (SiN) seed layer disposed over the substrate; and

a (200)-oriented texture titanium nitride (TiN) layer disposed over the SiN seed layer.

19. The integrated circuit of claim 18, wherein the one or more superconducting devices comprises a resonator device.

20. The integrated circuit of claim 19, wherein the resonator device comprises an interdigitated capacitor pattern formed by the SiN and (200)-oriented texture TiN layers.