Spurious junction prevention via in-situ ion milling

US11765985B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Vivekananda P. Adiga · Ossining, US
• Martin O. Sandberg · Ossining, US
• Jeng-Bang Yau · Yorktown Heights, US
• Keith E. Fogel · Potsdam, US
• John Bruley · Poughkeepsie, US
• Markus Brink · White Plains, US
• Benjamin Wymore · Somers, US

Key dates

• Filing date: Jun 22, 2020
• Grant date: Sep 19, 2023
• Expiry date: Jul 25, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N60/805

Abstract

Systems and techniques that facilitate spurious junction prevention via in-situ ion milling are provided. In various embodiments, a method can comprise forming a tunnel barrier of a Josephson junction on a substrate during a shadow evaporation process. In various instances, the method can further comprise etching an exposed portion of the tunnel barrier during the shadow evaporation process. In various embodiments, the shadow evaporation process can comprise patterning a resist stack onto the substrate. In various instances, the etching the exposed portion of the tunnel barrier can leave a protected portion of the tunnel barrier within a shadow of the resist stack. In various instances, the shadow of the resist stack can be based on a direction of the etching the exposed portion of the tunnel barrier. In various embodiments, the shadow evaporation process can further comprise depositing a first superconducting material on the substrate after the patterning the resist stack, oxidizing a surface of the first superconducting material to form the tunnel barrier, and depositing a second superconducting material over the protected portion of the tunnel barrier to form a Josephson junctio…