Effects of vacuum annealing and oxygen ion beam bombarding on the electrical and optical properties of ITO films deposited by E-beam evaporation

Abstract

Tin doped indium oxide (ITO) transparent conductive thin films with composition of 10 wt% SnO 2 and 89.8 wt% In 2 O 3 have been deposited by electron beam evaporation technique on K9 glass substrates at room temperature. The post annealing processes are done in vacuum with different annealing temperature at 100, 200, 300 and 350 ℃ for 1 hour, respectively. The oxygen ion energy is 800 eV; oxygen ion beam bombarding time is 10,20,30,40 and 50min, respectively. The results show that conductivity of ITO thin films are improved by increasing annealing temperature. The resistivity of the ITO thin films decrease from 5.2×10 −3 Ω ·cm at room temperature to 1.3×10 −3 Ω ·cm(350 ℃). The transmittance values of all samples in the visible range have been increased. As the oxygen ion beam bombarding time increases the resistivity reduce from 5.2×10 −3 Ω ·cm to 9×10 −4 Ω ·cm, the transmittance value improve from 66% to 82% at 550nm. Finally, the vacuum annealing and oxygen ion beam bombarding are done simultaneously, at temperature of 350 ℃ for 1 hours, ion bombardment time for 40 min. The resistivity of obtained ITO thin film is 7×10 −4 Ω ·cm .The maximum transmittance value is above 89% in the visible wavelength region.