High-barrier height Schottky diodes on N-InP by deposition on cooled substrates

Abstract
Ultrahigh barrier height (φB=0.96 eV) Schottky contacts to n‐InP, without an intentionally grown interficial oxide, were formed using metal deposition on a substrate cooled to as low as 77 K [low temperature (LT)]. φB = 0.46–0.52 eV for diodes deposited at room temperature (RT=300 K) agree well with previously published results, and give an ideality factor near unity. For the diodes deposited at LT=77 K, the leakage current density (J0) was reduced by more than 6–7 orders of magnitude with respect to the RT diodes. The φB for the LT diodes was increased from 0.48 to 0.96 eV for Pd metal and from 0.51 to 0.85 eV for Au metal, respectively. An alteration of the metal‐induced interface states, inhibition of surface segregation of the released In and P atoms, and very uniform metal coverage may be responsible for the distinct differences between the RT and LT diodes.