Cryogenic processing of metal/InP/Schottky contacts

Cryogenic processing has been shown to provide a simple way to greatly enhance the Schottky barrier height for Pd/n-InP diodes. Because of the reduction of the surface disruption and the improvement of the uniformity of the metal coverage, the room temperature barrier height of the Pd/n-InP diodes was increased from 0.48 to 0.96 eV with the substrate temperature decrease from 300 to 77 K. The leakage current density was also reduced by more than six orders of magnitude. It is obvious that the interface Fermi-level position lies well outside the variance associated with the Fermi-level pinning. This may be attributed to the formation of an insulator-like structure at the interface and the uniform metal coverage as confirmed by Raman studies. The stability of the low-temperature diode was revealed in this study.<>