Related papers: In-situ bandaged Josephson junctions for superconducting quantum processors

In-situ bandaged Josephson junctions for superconducting quantum processors

URL: http://arxiv.org/abs/2101.01453v3
Date: Sat, 9 Oct 2021 23:13:58 GMT
Title: In-situ bandaged Josephson junctions for superconducting quantum processors
Authors: Alexander Bilmes, Alexander K. H\"andel, Serhii Volosheniuk, Alexey V. Ustinov, and J\"urgen Lisenfeld
Abstract summary: Shadow evaporation is commonly used to micro-fabricate the key element of superconducting qubits - the Josephson junction. Here, we present an improved shadow evaporation technique allowing one to fabricate sub-micrometer-sized Josephson junctions together with bandage layers in a single lithography step.
Score: 101.18253437732933
License: http://creativecommons.org/licenses/by-nc-sa/4.0/
Abstract: Shadow evaporation is commonly used to micro-fabricate the key element of superconducting qubits - the Josephson junction. However, in conventional two-angle deposition circuit topology, unwanted stray Josephson junctions are created which contribute to dielectric loss. So far, this could be avoided by shorting the stray junctions with a so-called bandage layer deposited in an additional lithography step, which may further contaminate the chip surface. Here, we present an improved shadow evaporation technique allowing one to fabricate sub-micrometer-sized Josephson junctions together with bandage layers in a single lithography step. We also show that junction aging is significantly reduced when junction electrodes are oxidized in an oxygen atmosphere directly after deposition.

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