SACRIFICIAL SHORTING STRAPS FOR SUPERCONDUCTING QUBITS

• US 20160343934A1
• Filed: 05/18/2015
• Published: 11/24/2016
• Est. Priority Date: 05/18/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chang, Josephine B., McClure, Douglas T. III
• Granted Patent: US 9,515,247 B1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 29/66977 Quantum effect devices, e.g. using quantum reflection, diffraction or interference effects, i.e. Bragg- or Aharonov-Bohm effects
• CPC Class Codes: H10N 60/0912 of Josephson-effect devices
• CPC Class Codes: H10N 60/12 Josephson-effect devices
• CPC Class Codes: H10N 60/805 for Josephson-effect devices

Abstract

A technique relates to protecting a tunnel junction. A first electrode paddle and a second electrode paddle are on a substrate. The first and second electrode paddles oppose one another. A sacrificial shorting strap is formed on the substrate. The sacrificial shorting strap connects the first electrode paddle and the second electrode paddle; The tunnel junction is formed connecting the first electrode paddle and the second electrode paddle, after forming the sacrificial shorting strap. The substrate is mounted on a portion of a quantum cavity. The portion of the quantum cavity is placed in a vacuum chamber. The sacrificial shorting strap is etched away in the vacuum chamber while the substrate is mounted to the portion of the quantum cavity, such that the sacrificial shorting strap no longer connects the first and second electrode paddles. The tunnel junction has been protected from electrostatic discharge by the sacrificial shorting strap.

Claims

1-16. -16. (canceled)

17. A system for protecting a tunnel junction from electrostatic discharge when handling the tunnel junction, the system comprising:

a quantum cavity configured as a waveguide enclosure;

an assembly mounted to the quantum cavity;

wherein the assembly includes;

a first electrode paddle and a second electrode paddle both formed on an upper surface of a substrate, the first electrode paddle and the second electrode paddle opposing one another;

the tunnel junction connecting the first electrode paddle and the second electrode paddle, the tunnel junction formed on the upper surface of the substrate such that the tunnel junction, the first electrode paddle, and the second electrode paddle are in a same plane; and

a first location on the first electrode paddle and a second location on the second electrode paddle, the first electrode paddle having a first raised portion at the first location and the second electrode paddle having a second raised portion at the second location, the first and second raised portion being material of the substrate;

wherein the first raised portion corresponds to one end of a sacrificial shorting strap previously connected at the first location on the first electrode paddle; and

wherein the second raised portion corresponds to another end of the sacrificial shorting strap previously connected at the second location on the second electrode paddle.

18. The system of claim 17, wherein the first raised portion and the second raised portion are material of the first electrode paddle and the second electrode paddle.

19. The system of claim 18, wherein the first raised portion of the material has a higher height at the first location than other areas of the material of the first electrode paddle;

and

wherein the second raised portion of the material has a higher height at the second location than other areas of the material of the second electrode paddle.

20. The system of claim 17, wherein the first location includes a residual portion of the sacrificial shorting strap;

wherein the second location includes another residual portion of the sacrificial shorting strap; and

wherein the residual portion and the another residual portion of the sacrificial shorting strap do not overhang from the first and second electrode paddles, respectively.

21. The system of claim 20, wherein the assembly is void of the sacrificial shorting strap such that no sacrificial shorting strap connects the first electrode paddle to the second electrode paddle.