Aluminum air bridges for superconducting quantum devices realized using a single step electron-beam lithography process

• URL: http://arxiv.org/abs/2206.09489v2
• Date: Wed, 31 Aug 2022 16:26:29 GMT
• Title: Aluminum air bridges for superconducting quantum devices realized using a single step electron-beam lithography process
• Authors: Noah Janzen, Michal Kononenko, Shaun Ren, Adrian Lupascu
• Abstract summary: In superconducting quantum devices, air bridges enable increased circuit complexity and density. We implement aluminum air bridges using a simple process based on single-step electron-beam gradient exposure. The resulting bridges have sizes ranging from $20mu m$ to $100mu m$, with a yield exceeding $99%$ for lengths up to $36mu m$.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: In superconducting quantum devices, air bridges enable increased circuit complexity and density as well as mitigate the risk of microwave loss arising from mode mixing. We implement aluminum air bridges using a simple process based on single-step electron-beam gradient exposure. The resulting bridges have sizes ranging from $20~\mu m$ to $100~\mu m$, with a yield exceeding $99~\%$ for lengths up to $36~\mu m$. When used to connect ground planes in coplanar waveguide resonators, the induced loss contributed to the system is negligible, corresponding to a reduction of the quality factor exceeding $1.0\times10^8$ per bridge. The bridge process is compatible with Josephson junctions and allows for the simultaneous creation of low loss bandages between superconducting layers.

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