CHARACTERIZATION OF THE OXIDIZED INDIUM THIN-FILMS WITH THERMAL-OXIDATION

Oxidized indium thin films on several substrates were formed by indium deposition and thermal oxidation. The oxidation was carried out in ox ygen ambient at temperatures ranging from 500 to 900 degrees C for 1 h . In the scanning electron microscopy measurements, the oxidized indiu m films were shown to be composed of grains with sizes of 400 to 600 n m which agglomerate subgrains with diameters of 40-60 nm. From the mea surements of X-ray diffraction, X-ray photoelectron spectroscopy and A uger electron spectroscopy, it was confirmed that the oxidized indium are cubic indium oxide (In2O3) polycrystallites. In addition, no eleme nts other than In and O atoms were found from secondary ion mass spect roscopy measurements. A strong orange photoluminescence, peaking at 63 7 nn, was observed at room temperature for these films. It was assumed that a center of orange luminescence in the indium oxide films may be related to oxygen deficiencies or defects.