Superconducting Through-Silicon Vias for Quantum Integrated Circuits

TL;DR

This paper presents a microfabrication process for superconducting through-silicon vias, enabling reliable high-quality superconducting connections in quantum processors, validated by zero resistance measurements.

Contribution

It introduces a novel fabrication method for superconducting vias with sloped walls suitable for quantum circuits, using non-conformal deposition techniques.

Findings

Zero via-to-via resistance below aluminum's critical temperature

Reliable superconducting films deposited by electron-beam evaporation and sputtering

Compatible with quantum processor fabrication processes

Abstract

We describe a microfabrication process for superconducting through-silicon vias appropriate for use in superconducting qubit quantum processors. With a sloped-wall via geometry, we can use non-conformal metal deposition methods such as electron-beam evaporation and sputtering, which reliably deposit high quality superconducting films. Via superconductivity is validated by demonstrating zero via-to-via resistance below the critical temperature of aluminum.