Superconductor device interconnect structure

Patent metadata

Field	Value
Publication number	US-9780285-B1
Application number	US-201615238375-A
Country	US
Kind code	B1
Filing date	Aug 16, 2016
Priority date	Aug 16, 2016
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A method is provided of forming a superconductor device interconnect structure. The method includes forming a first dielectric layer overlying a substrate, and forming a base electrode in the first dielectric layer with the base electrode having a top surface aligned with the top surface of the first dielectric layer. The method further comprises forming a Josephson junction (JJ) over the base electrode, depositing a second dielectric layer over the JJ, the base electrode and the first dielectric layer, and forming a first contact through the second dielectric layer to the base electrode to electrically couple the first contact to a first end of the JJ, and a second contact through the second dielectric layer to a second end of the JJ.

First claim

What is claimed is:

1. A method of forming a superconductor device interconnect structure, the method comprising:
forming a first dielectric layer overlying a substrate;
forming a base electrode in the first dielectric layer, the base electrode having a top surface aligned with the top surface of the first dielectric layer;
forming a Josephson junction (JJ) over the base electrode;
depositing a second dielectric over the JJ, the base electrode and the first dielectric layer; and
forming a first contact through the second dielectric layer to the base electrode to electrically couple the first contact to a first end of the JJ, and a second contact through the second dielectric layer to a second end of the JJ.

2. The method of claim 1 , wherein the JJ is formed from an Aluminum/Aluminum oxide layer disposed between the base electrode and a niobium layer.

3. The method of claim 2 , wherein the base electrode is formed from niobium.

4. The method of claim 1 , wherein the second contact has a diameter that is smaller than the diameter of the JJ.

5. The method of claim 1 , wherein the dielectric material employed in the first dielectric layer and the second dielectric layer is a material that can form the dielectric first and second material layers at a temperature of about 160° Celsius.

6. The method of claim 1 , further comprising forming a first conductive line overlying the first contact and second conductive line overlying the second contact, wherein the first and second conductive lines have a top surface that is aligned with a top surface of the second dielectric layer.

7. The method of claim 6 , wherein the first and second contacts and the first and second conductive lines are formed by a dual damascene process.

8. The method of claim 1 , wherein the base electrode is formed by a single damascene process.

9. The method of claim 1 , wherein the formation of the JJ comprises:
depositing an aluminum layer over the base electrode and the first dielectric layer;
oxidizing the aluminum layer to form an aluminum oxide layer on the top surface of the aluminum layer;
forming a niobium layer over the aluminum oxide layer;
depositing and patterning a photoresist material layer over the niobium layer to define dimensions of the Josephson junction;
etching the niobium layer, the aluminum oxide layer and the aluminum layer to form a JJ and remove the remaining portions of the niobium layer, the aluminum oxide layer and the aluminum layer; and
stripping the photoresist material layer.

10. The method of claim 1 , further comprising forming one or more layers between the substrate and the first dielectric layer.

11. A method of forming a superconductor device interconnect structure, the method comprising:
forming a first dielectric layer overlying a substrate;
forming a niobium base electrode in the first dielectric layer, the niobium base electrode having a top surface aligned with the top surface of the first dielectric layer;
depositing an aluminum layer over the base electrode and the first dielectric layer;
oxidizing the aluminum layer to form an aluminum oxide layer on the top surface of the aluminum layer;
forming a niobium layer over the aluminum oxide layer;
depositing and patterning a photoresist material layer over the niobium layer to define dimensions of the Josephson junction (JJ);
etching the niobium layer, the aluminum oxide layer and the aluminum layer to form a JJ based on the defined dimensions and removing the remaining portions of the niobium layer, the aluminum oxide layer and the aluminum layer;
stripping the photoresist material layer;
depositing a second dielectric layer over the JJ, the base electrode and the first dielectric layer;
forming a first contact through the second dielectric layer to the base electrode to electrically couple the first contact to a first end of the JJ, and a second contact through the second dielectric to a second end of the JJ; and
forming a first conductive line overlying the first contact and second conductive line overlying the second contact, wherein the first and second conductive lines have a top surface that is aligned with a top surface of the second dielectric layer.

12. The method of claim 11 , wherein the second contact has a diameter that is smaller than the diameter of the JJ.

13. The method of claim 11 , wherein the dielectric material employed in the first dielectric layer and the second dielectric layer is a material that can form the dielectric first and second material layers at a temperature of about 160° Celsius.

14. The method of claim 11 , wherein the first and second contacts and the first and second conductive lines are formed by a dual damascene process.

15. The method of claim 11 , wherein the base electrode is formed by a single damascene process.

16. A superconductor device interconnect structure comprising:
a first dielectric layer overlying a substrate;
a niobium base electrode disposed in the first dielectric layer, the niobium base electrode having a top surface aligned with the top surface of the first dielectric layer;
a Josephson junction (JJ) disposed over and in contact with the base electrode;
a second dielectric that overlays the JJ, the base electrode and the first dielectric layer;
a first contact that extends through the second dielectric layer from a top surface of the second dielectric layer to the base electrode to electrically couple the first contact to a first end of the JJ; and
a second contact that extends through the second dielectric layer to a second end of the JJ.

17. The structure of claim 16 , wherein the JJ is formed from an Aluminum/Aluminum oxide layer disposed between the base electrode and a niobium layer.

18. The structure of claim 16 , wherein the second contact has a diameter that is smaller than the diameter of the JJ.

19. The structure of claim 16 , wherein the dielectric material employed in the first dielectric layer and the second dielectric layer is a material that can form the dielectric first and second layers at a temperature of about 160° Celsius.

20. The structure of claim 16 , further a first conductive line overlying the first contact and a second conductive line overlying the second contact, wherein the first and second conductive lines have a top surface that is aligned with a top surface of the second dielectric layer.

Assignees

• Kirby Christopher F
• Rennie Michael
• O'Donnell Daniel J
• Northrop Grumman Systems Corp

Inventors

• Kirby Christopher F
• Rennie Michael
• O'Donnell Daniel J

Classifications

• H01L39/2493

  Electricity · mapped topic

• H01L39/025

  Electricity · mapped topic

• H01L39/223 Primary

  Electricity · mapped topic

• H01L39/2406

  Electricity · mapped topic

• H10N60/0912 Primary

  of Josephson-effect devices · CPC title