Plasma cleaning of superconducting layers

US9425376B2 · kind B2 · utility

Assignee

• INTERMOLECULAR, INC. · US

Inventors

• Frank Greer · Pasadena, US
• Andy Steinbach · San Jose, US

Key dates

• Filing date: Dec 23, 2013
• Grant date: Aug 23, 2016
• Expiry date: Sep 25, 2034

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N60/0912

Abstract

In a “window-junction” formation process for Josephson junction fabrication, a spacer dielectric is formed over the first superconducting electrode layer, then an opening (the “window” is formed to expose the part of the electrode layer to be used for the junction. In an atomic layer deposition (ALD) chamber (or multi-chamber sealed system) equipped with direct or remote plasma capability, the exposed part of the electrode is sputter-etched with Ar, H2, or a combination to remove native oxides, etch residues, and other contaminants. Optionally, an O2 or O3 pre-clean may precede the sputter etch. When the electrode is clean, the tunnel barrier layer is deposited by ALD in-situ without further oxidant exposure.