Ultrathin silicon membranes to study supercurrent transport in crystalline semiconductors

We have developed a two-step anisotropic etching process to fabricate thin silicon membranes, used to study supercurrent transport in semiconductor coupled weak links. The process uses a shallow BF2+ implantation, and permits easy control of membrane thickness less-than-or-equal-to 100 nm. Preliminary measurements on membrane-based Nb-Si-Nb junctions reveal the simultaneous occurrence of tunnel behavior and Josephson coupling