Semiconductor-superconductor hybrid device and its fabrication
A method of fabricating a semiconductor-superconductor hybrid device comprises providing a workpiece comprising a semiconductor component, a layer of a first superconductor material on the semiconductor component, and a layer of a second superconductor material on the first superconductor material, the second superconductor material being different from the first superconductor material; etching the layer of the second superconductor material to expose a portion of the first superconductor material; and oxidising the portion of the first superconductor material to form a passivating layer on the semiconductor. The first superconductor provides energy coupling between the semiconductor and the second superconductor, and the passivating layer protects the semiconductor while allowing electrostatic access thereto. Also provided are a hybrid device, and a method of etching.
1. A semiconductor-superconductor hybrid device, comprising:
a semiconductor component;
a first superconductor component over a first portion of the semiconductor component, the first superconductor component comprising a first superconductor material;
a second superconductor component on the first superconductor component, the second superconductor component comprising a second superconductor material different from the first superconductor material; and
a passivating layer over a second portion of the semiconductor component, the passivating layer comprising an oxide of the first superconductor material.
2. The semiconductor-superconductor hybrid device according to claim 1 , wherein the first superconductor material is aluminium.
3. The semiconductor-superconductor hybrid device according to claim 1 , wherein the second superconductor material is selected from the group consisting of lead, indium, vanadium, tantalum, tin, rhenium and niobium.
4. The semiconductor-superconductor hybrid device according to claim 1 , further comprising an additional component on the semiconductor component, wherein the first superconductor component and the passivating layer are arranged on the additional component.
5. The semiconductor-superconductor hybrid device according to claim 1 , further comprising a gate electrode situated to apply an electrostatic field to the semiconductor component.
6. The semiconductor-superconductor hybrid device according to claim 1 , wherein the first superconductor material has a thickness of less than or equal to 3 nm.
7. The semiconductor-superconductor hybrid device according to claim 1 , wherein the second superconductor material is lead.
8. The semiconductor-superconductor hybrid device according to claim 1 , wherein the second superconductor material is niobium.
9. The semiconductor-superconductor hybrid device according to claim 1 , wherein thickness of the passivating layer is selected to be thick enough to protect the hybrid device from oxidation.
10. The semiconductor-superconductor hybrid device according to claim 1 , wherein the semiconductor component comprises III-V semiconductor materials of the general formula:
InAs x Sb 1−x ,
where x is in the range 0 to 1.
11. The semiconductor-superconductor hybrid device according to claim 1 , wherein the semiconductor component comprises at least one of indium antimonide, indium arsenide.
12. The semiconductor-superconductor hybrid device according to claim 1 , wherein the semiconductor component comprises a ternary mixture comprising 50% indium on a molar basis and variable proportions of arsenic and antimony.
13. The semiconductor-superconductor hybrid device according to claim 1 , wherein the semiconductor component is a nanowire.
14. The semiconductor-superconductor hybrid device according to claim 1 , wherein the second superconductor material comprises at least one of: NbN, NbTiN, MgB 2 , MoRe, or Fe-based superconductors.
15. A semiconductor-superconductor hybrid device, comprising:
a semiconductor component;
a first superconductor component over a first portion of the semiconductor component, the first superconductor component comprising a layer of a first superconductor material, said first superconductor material being aluminium or indium;
a second superconductor component on the first superconductor component, the second superconductor component comprising a second superconductor material different from the first superconductor material; and
a passivating layer over a second portion of the semiconductor component, the passivating layer comprising an oxide of the first superconductor material.
16. The semiconductor-superconductor hybrid device according to claim 15 , wherein the second superconductor material is selected from lead, indium, vanadium, tantalum, tin, rhenium and niobium.
17. The semiconductor-superconductor hybrid device according to claim 15 , wherein the layer of the first superconductor material has a thickness of less than or equal to 3 nm.
18. The semiconductor-superconductor hybrid device according to claim 15 , wherein the semiconductor component comprises at least one of indium antimonide, indium arsenide.
19. The semiconductor-superconductor hybrid device according to claim 15 , wherein the second superconductor material comprises at least one of: NbN, NbTiN, MgB 2 , MoRe, or Fe-based superconductors.
20. A semiconductor-superconductor hybrid device, comprising:
a semiconductor component;
a first superconductor component over a first portion of the semiconductor component, the first superconductor component comprising a first superconductor material that undergoes self-limiting oxidation;
a second superconductor component on the first superconductor component, the second superconductor component comprising a second superconductor material different from the first superconductor material; and
a passivating layer over a second portion of the semiconductor component, the passivating layer comprising an oxide of the first superconductor material.
21. The semiconductor-superconductor hybrid device according to claim 20 , wherein the second superconductor material is selected from lead, indium, vanadium, tantalum, tin, rhenium and niobium.