Electrical properties and the determination of interface state density from I-V, C-f and G-f measurements in Ir/Ru/n-InGaN Schottky barrier diode

The electrical properties of the Ir/Ru Schottky contacts on n-InGaN have been investigated by current-voltage (I-V), capacitance-voltage (C-V), capacitance-frequency (C-f) and conductance-frequency (G-f) measurements. The obtained mean barrier height and ideality factor from I-V are 0.61 eV and 1.89. The built-in potential, doping concentration and barrier height values are also estimated from the C-V measurements and the corresponding values are 0.62 V, 1.20x10 17 cm -3 and 0.79 eV, respectively. The interface state density (N SS ) obtained from forward bias I-V characteristics by considering the series resistance (R S ) values are lower without considering the series resistance (R S ). Furthermore, the interface state density (N SS ) and relaxation time (tau) are also calculated from the experimental C-f and G-f measurements. The N SS values obtained from the I-V characteristics are almost three orders higher than the N SS values obtained from the C-f and G-f measurements. The experimental results depict that N SS and tau are decreased with bias voltage. The frequency dependence of the series resistance (R S ) is attributed to the particular distribution density of interface states. DOI: 10.21883/FTP.2017.12.45189.8340