  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.
