DIELECTRIC-PROPERTIES OF TIN OXIDE THIN-FILM CAPACITORS

Thin films of several thicknesses in the form of MIM structures are prepared from the powders of tin oxide (SnO2) by thermal evaporation technique in a vacuum of 10(-5) Torr. The dielectric properties of tin oxide film capacitors have been studied with temperatures varying from 77 to 400 K and also with frequency. At 77 K the values of capacitance and loss tangent are small for these films. With increasing temperature the values of capacitance and loss tangent increase. The capacitance-temperature plots show peak values of capacitance at 345 K for 1 kHz, 350 K for 2 kHz, 360 K for 5 kHz and 368 K for 10 kHz. These peak values of capacitance can be eliminated by repeated heating and cooling of the structures. The activation energy for the migration of charge carriers is calculated for tin oxide films and is found to be 0.13 eV. The results obtained on the dielectric properties of tin oxide thin films are presented and discussed.