Characterization of TiO2 and TiO2-HfO2 Transparent Thin Films for Microelectronics Applications

Transparent oxide semiconductors (TOSs) based on TiO₂-doped matrix have been recently studied for their possible microelectronics applications. In the present work, TiO₂ and Hf-doped TiO₂ thin films were prepared by low pressure hot target reactive magnetron sputtering (LP HTRS) and deposited onto monocrystalline (100) silicon substrate. After deposition thin films were additionally annealed in air for 4 hours at 1000 K. Properties of the thin films matrixes were studied by means of X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). XRD investigations have shown that heat treatment enhances the crystallity of the thin films. Well-shaped lines of the rutile phase for TiO₂ and the orthorhombic HfTiO₄ have appeared. AFM images showed that the nanocrystalline thin films exhibit the high ordering grade. The dimension and arrangement of grains were homogenous on the whole sample surface. The stoichiometry of manufactured thin films was confirmed by XPS examinations