Electrical Characterization of in Schottky Contacts to Epitaxial n-In_0.46Ga_0.54P Grown on n⁺-GaAs by Mocvd

Abstract

In/n-In_0.46Ga_0.54P Schottky diode was fabricated by thermal evaporation of In on chemically etched surface of In_0.45Ga_0.54P:Si epitaxial layer grown on highly doped n type GaAs. The In metal formed a high quality rectifying contact to In_0.46Ga_0.54P:Si with a rectification ratio of 500. The direct current-voltage/temperature (I-V/T) characteristics were non-ideal with the values of the ideality factor (n) between 1.26-1.78 for 400&gt;T&gt;260 K. The forward I-V data strongly indicated that the current was controlled by the generation-recombination (GR) and thermionic emission (TE) mechanisms for temperature in the range 260-400 K. From the temperature variation of the TE reverse saturation current, the values of (0.75±0.05)V and the (4.5±0.5)×10^-5 Acm^-2K^-2 for the zero bias zero temperature barrier height (φ_oo) and modified effective Richardson constant were obtained. The 1 MHz capacitance-voltage (C-V) data for 260 K < T < 400 K was analyzed in terms of the C^-2-V relation including the effect of interface layer to obtain more realistic values of the barrier height (φ_bo). The temperature dependence of φ_bo was described the relation φ_bo =(0.86±10.03) - (8.4±0.7)×l0^-4T. The values of φ_oo, obtained by the I-V and C-V techniques agreed well.