Fabrication of transparent lateral CoSi₂/TiSi₂contact junctions

We demonstrate two-step electron-beam lithographic fabrication of transparent disilicide superconductor/normal-metal CoSi2/TiSi2 contact junctions, where CoSi2 is a superconductor (S) with a transition temperature T c ≈ 1.5 K, and TiSi2 is a normal-metal (N). The lateral S/N contact junction is embedded in a silicon substrate. The fabrication processes are compatible with the state-of-the-art silicon-based integrated-circuit technology. We show potential advantages of these junctions over conventional (tunnel) junctions where S and N are vertically stacked on a substrate. We propose that epitaxial CoSi2/Si heterostructures may be used as a basis in superconducting devices and qubits.