Dielectric and electrical properties of SnO2, Sb2O3, and their mixed films

The dielectric and electrical properties of sandwiched AlSnO2Al, AlSb2O3Al, and Al(SnO2 + Sb2O3)Al structures of different thicknesses are investigated. The ac. capacitance and tan δ increase with decrease in frequency in all these films. A comparison of the capacitance values of these films shows that the values of the capacitance are larger in mixed films as compared to the values of capacitance in SnO2 and Sb2O3 films. The variation of tan δ with frequency for mixed films lies between to that of SnO2 and Sb2O3 films. Currentvoltage characteristics of these films show that the breakdown voltage increases and the dielectric strength decreases with increase in film thickness in all the three types of films. The logarithm of breakdown field strength is plotted against the logarithm of the film thickness for the three types of films. Photomicrographs of the breakdown patterns at different stages of voltage are given and the results are explained.