Studies on the preferred orientation changes and its influenced properties on ITO thin films

Indium Tin Oxide thin films were deposited using reactive thermal deposition technique from the In-Sn alloy source. Deposition of either (400) or (222) predominant planes was obtained between (400) and (222) planes by changing the deposition rate. Low electrical resistivity of 3.32 x 10(-4) Omega cm and good polycrystalline structure was obtained for the films with (400) predominant planes, deposited at 170 degrees C substrate temperature. Decrease in the band gap value was observed during the change in the crystallization from (222) to (400) predominant planes using optical absorption and reflectance spectra measurements. High thermoelectric power of 69.99 mu V/degrees C was measured for the films with (400) predominant planes and 37.5 mu V/degrees C was obtained for (222) predominant planes. Annealing treatment on the (400) films under nitrogen atmosphere for 60 min at 310 degrees C resulted in realignment of atoms from (400) to (222) planes. Structural, optical and electrical characterization studies revealed that the films oriented with (400) planes were more oxygen deficient than the films with (222) preferred planes. (C) 1997 Elsevier Science Ltd.