Ti-Seeded Sn Growth on InAs Nanowires for Hybrid Superconductor–Semiconductor Devices

Tin has recently gained attention as a promising superconductor for hybrid superconductor–semiconductor nanowire devices due to its relatively high critical temperature and large superconducting gap compared to conventionally used Aluminum. These properties make Sn an attractive material for applications such as transmons, Josephson parametric amplifiers and for hosting topological states in InAs based nanowire platforms. However, Sn deposition presents a major challenge, as it tends to dewet at elevated temperatures, requiring substrate cooling below 80 K to achieve uniform coverage. In this work, we investigate the effect of a thin titanium seed layer of 2–3 nm as an adhesion layer for Sn deposition. Prior to deposition, atomic hydrogen cleaning is performed to ensure a transparent interface on InAs nanowires. Scanning electron microscopy reveals that Ti seeding improves film uniformity. We further evaluate the transport characteristics of Ti-seeded Sn films integrated into hybrid nanowire devices to assess the resulting superconducting behavior and interface transparency.