Superconducting TiN through-silicon-vias for quantum technology

Through-silicon vias (TSVs) can be used to route signals and to obtain effective grounding in microwave circuits. The coating of the TSVs with a superconducting material is a challenge because of the high aspect ratio of the structures. In this paper, we present successful fabrication of superconducting 60 μm diameter TSVs, coated by atomic layer deposition (ALD) of titanium nitride. The critical temperature T
_c
is approximately 1.6 K.