The capacitance-voltage (C-V) and conductance-voltage (G/omega-V) characteristics of the Au/n-GaAs Schottky barrier diodes (SBDs) have been investigated for 10, 100 and 500 kHz at 80 and 280 K. To evaluate the reason of non-ideal behavior in C-V and G/omega-V plots, the measured C and G/omega values were corrected by taking into accounts series resistance effect. Experimental results show that the values of C and G/omega were found to be a strong function of interface states (N-ss) at inverse and depletion regions especially at low frequencies, but R-s is effective only at the accumulation region especially at high frequencies. Such behavior of the C and G/omega values may be attributed to an increase in polarization especially at low frequencies and the existence of N-ss or dislocations between metal and semiconductor. It can be concluded that the increase in C and G/omega at low frequencies especially at weak and depletion regions results from the existence of N. The values of doping concentration (N-d) and barrier height (BH) between metal and semiconductor were also obtained from the linear part of high frequency (500 kHz) C-2 vs. V plots at 80 and 280 K, respectively. (C) 2014 Elsevier Ltd. All rights reserved.