The effect of thermal annealing on the series resistance of nearly ideal and ideal Ti/n-GaAs Schottky diodes

The effect of annealing in the temperature range 100-300 degrees C with ste ps of 100 degrees C for 5 min on characteristic parameters, especially seri es resistance, of nearly ideal (D1) and ideal (D2) Ti/n-GaAs Schottky barri er diodes (SBDs) has been investigated. Both Ti/n-GaAs SBDs have shown ther mal stability up to 300 degrees C annealing. It can be said that the interf acial layer thickness of sample D1 is too thin to hinder thermal stability. The ideality factor and barrier height of samples D1 and D2 have been foun d to be 1.05 and 0.76 eV and 1.06 and 0.75eV at 300 degrees C respectively, while 1.08 and 0.64eV and 1.01 and 0.67 eV for their as-deposited samples, respectively. The series resistance values have decreased with increasing annealing temperature. This has been attributed to reduction of the native oxide layer by the metal Ti It has been concluded that the annealing to a g iven temperature has improved the electrical characteristics of both Ti/n-G aAs Schottky contacts due to chemical reactions between substrate and the r eactive metals and the native oxide.