Ru/Ti Schottky Contacts on N-type In-P (100): Temperature Dependence of Current-Voltage (I-V) Characteristics

The current-voltage characteristics (I-V) of Ru/Ti/n-InP (100) schottky diodes have been measured in the temperature range of 200-400oC. These are analyzed using thermionic emission theory (TE) by incorporating the concept of barrier inhomogeneity at the metal/semiconductor interface through a Gaussian distribution factor. The forward and reverse I-V characteristics are analyzed to estimate the Schottky barrier parameters. It has revealed that decrease of barrier height and increase of ideality factor as the temperature increases. The barrier height (Фb) is found to be 0.82 eV, 0.81 eV, 0.80 eV and 0.79 eV for as-deposited sample, annealed at 200oC, 300oC and 400oC respectively. The ideality factor in the same temperature range are found to be 1.19, 1.26, 1.59, 1.64 and this is good agreement with the Cheung's function dV/dln(I) vs. I. The series resistance values are evaluated in the range of 16MΩ – 62 MΩ with increasing temperature. The nonlinearity in the Richardson plot and Schottky barrier heights may be attributed to the formation of phosphide phases at the Ru/Ti/n-InP interface.