SCHOTTKY-BARRIER HEIGHT ENHANCEMENT IN N-INP FOR MESFET APPLICATIONS

We report the enchancement of Schottky barrier height in n-InP using a dry, room temperature process for surface passivation prior to metal deposition. Barrier height values as high as phi-b = 0.83eV have been obtained from current-voltage (I-V) characteristics that were linear over several orders of magnitude of current. The process, reported for the first time here, involves the growth of a thin (10-30-angstrom) native oxide, layer and appears to produce a stable, reproducible surface. Auger electron spectroscopy of the passivated surface revealed a phosphorus oxide elemental indium (In oxide?) and a phosphorus rich interface. The enhancement of barrier height is discussed in terms of the Fermi level at the interface. The process has significant impact to the current state of InP MESFET technology.