Thermal Annealing Effects on Electrical Properties of Ir/Ru Schottky Contacts on n-InGaN

Effects of annealing on electrical properties of Ir/Ru Schottky contacts on n-InGaN have been investigated by current-voltage (I-V) measurements. The Schottky barrier height (SBH) is found to be 0.61 eV for as-deposited Ir/Ru Schottky contacts. For the contacts annealed at 200 and 300 degrees C, the SBH slightly increases and then slightly decreases after annealing at 400 degrees C and 500 degrees C. The series resistance (R-S) can be determined using Cheung's method. Besides, the energy distributions of interface state densities are determined by using the Terman's method. It is noted that the electrical properties of Ir/Ru Schottky contacts are improved after annealing at 300 degrees C. Based on these results, it is clear that Ir/Ru Schottky contact is an attractive metallization scheme for the fabrication of InGaN-based device applications.