Barrier height enhancement of Schottky diodes on n-In_0.53Ga _0.47As by cryogenic processing

Schottky contacts on n-In_0.53Ga_0.47As have been made by metal deposition on substrates cooled to a temperature of 77 K. The current-voltage and capacitance-voltage characteristics showed that the Schottky diodes formed at low temperature had a much improved barrier height compared to those formed at room temperature. The Schottky barrier height φ_B, was found to be increased from ∼0.2 to 0.60 eV with Ag metal. For the low temperature diode, the saturation current density, J ₀, was about four orders smaller than for the room temperature diode. Deep level transient spectroscopy studies of n-InGaAs low temperature diodes exhibited one electron trap located at E_c-0.23 eV. This trap level was identified as a bulk trap.