Atomic vapor deposition approach to In ₂O ₃ thin films

In ₂O ₃ thin films were grown by atomic vapor deposition (AVD) on Si(100) and glass substrates from a tris-guanidinate complex of indium [In(NiPr ₂guanid) ₃] under an oxygen atmosphere. The effects of the growth temperature on the structure, morphology and composition of In ₂O ₃ films were investigated. X-ray diffraction (XRD) measurements revealed that In ₂O ₃ films deposited in the temperature range 450-700°C crystallised in the cubic phase. The film morphology, studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), was strongly dependent on the substrate temperature. Stoichiometric In ₂O ₃ films were formed under optimised processing conditions as was confirmed by X-ray photoelectron and X-ray excited Auger electron spectroscopies (XPS, XE-AES), as well as by Rutherford backscattering spectrometry (RBS). Finally, optical properties were investigated by photoluminescence (PL) measurements, spectroscopic ellipsometry (SE) and optical absorption. In ₂O ₃ films grown on glass exhibited excellent transparency (≈90%) in the Visible (Vis) spectral region.