Table of Contents
Journal of Metallurgy
Volume 2012 (2012), Article ID 531915, 9 pages
http://dx.doi.org/10.1155/2012/531915
Research Article

Electrical Properties of Rapidly Annealed Ir and Ir/Au Schottky Contacts on n-Type InGaN

Department of Physics, Sri Venkateswara University, Tirupati 517 502, India

Received 23 August 2011; Accepted 24 October 2011

Academic Editor: Stefano Gialanella

Copyright © 2012 V. Rajagopal Reddy et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The effect of annealing temperature on electrical characteristics of iridium (Ir) and iridium/gold (Ir/Au) Schottky contacts to n-type InGaN have been investigated by means of current-voltage (I-V) and capacitance-voltage (C-V) techniques. It is observed that the barrier height of Ir/n-InGaN and Au/Ir/n-InGaN Schottky diodes increases after annealing at 3 0 0 C for 1 min in N 2 ambient compared to the as-deposited. However, the barrier heights are found to be decreased somewhat after annealing at 5 0 0 C for the both Ir and Ir/Au Schottky contacts. From the above observations, it is clear that the optimum annealing temperature for both Ir and Ir/Au Schottky contacts is 3 0 0 C . Moreover, the barrier height ( 𝜙 𝑏 ), ideality factor (n) and series resistance ( 𝑅 𝑆 ) are determined using Cheung’s and Norde methods. Besides, the energy distribution of interface state densities are determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. Based on the above results, it is clear that both Ir and Ir/Au Schottky contacts exhibit a kind of thermal stability during annealing.