Schottky barrier and contact resistance at a niobium/silicon interface

Electrical transport properties of niobium-silicon contacts are reported over a wide doping range. It is found that a short low-energy argon plasma sputtering of the silicon surface prior to metal deposition lowers the Schottky barrier height by 0.12 eV, without degrading diode ideality. This result is interpreted as a partial explanation for the dependence of the superconducting proximity effect in semiconductors on sputter cleaning.