The temperature dependent reverse bias leakage current-voltage (I-r-V-r) of the Au/Ca3Co4Ga0.001Ox/n-Si structure has been investigated in the temperature range of 80-340 K. The Ln(J(r)/E-r) vs E-0.5 plots show straight lines with different slopes in the intermediate reverse bias voltages for each temperature. Both the intercepts B(T) and slopes m(T) values were obtained from these plots for each temperature. Their values vs q/kT plots were drawn and they show a linear behavior except for two low temperatures (80 and 120 K). The dielectric constant (epsilon(s)) of interfacial Ca3Co4Ga0.001Ox. layer and the barrier height (phi(t)) which is necessary electron emission from the trap values were found from the slope of these plots, respectively. Experimental results show that the I-r-V-r, characteristics can be well described by the electric field dependence so the dominant conduction mechanisms are either Frenkel-Poole emission (FPE) or Schottky emission (SE) in this structure. The es and phi(t) values were found as 3.1 and 37.1 meV, respectively. It is clear that the value of phi(t) is considerably low and the value of dielectric constant (3.1) is closed to the dielectric value conventional of SiO2 insulator layer. These results confirmed that the (Ca3Co4Ga0.001Ox) interfacial layer can be used instead of a conventional of SiO2 insulator layer in the terms of flexibility, easy production and low cost. (C) 2014 Elsevier Ltd. All rights reserved.