Influence of Series Resistance and Interface State Density on Electrical Characteristics of Ru/Ni/n-GaN Schottky structure

• Published in: Journal of semiconductor technology and science Vol. 13; no. 5; pp. 492 - 499
• Main Authors: Reddy, M. Siva Pratap, Kwon, Mi-Kyung, Kang, Hee-Sung, Kim, Dong-Seok, Lee, Jung-Hee, Reddy, V. Rajagopal, Jang, Ja-Soon
• Format: Journal Article
• Language: Korean
• Published: 2013
• Subjects: interface state density; series resistance; Ru/Ni/n-GaN; Terman's method
• ISSN: 1598-1657

We have investigated the electrical properties of Ru/Ni/n-GaN Schottky structure using current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature. The barrier height (${\Phi}_{bo}$) and ideality factor (n) of Ru/Ni/n-GaN Schottky structure are found to be 0.66 eV and 1.44, respectively. The ${\Phi}_{bo}$ and the series resistance ($R_S$) obtained from Cheung's method are compared with modified Norde's method, and it is seen that there is a good agreement with each other. The energy distribution of interface state density ($N_{SS}$) is determined from the I-V measurements by taking into account the bias dependence of the effective barrier height. Further, the interface state density $N_{SS}$ as determined by Terman's method is found to be $2.14{\times}10^{12}\;cm^{-2}\;eV^{-1}$ for the Ru/Ni/n-GaN diode. Results show that the interface state density and series resistance has a significant effect on the electrical characteristics of studied diode.