Chloride atomic-layer chemical vapor deposition of TiO2 with a chloride pretreatment of substrates

A procedure for changing the course of the atomic-layer chemical vapor deposition (ALCVD) growth of TiO2 from TiCl4 and H2O on amorphous SiO2 substrates/underlayers at low temperatures is proposed. The changes are characterized by the real-time incremental dielectric reflection measurements and post-growth spectrophotometry and reflection high-energy electron diffraction measurements. In the procedure, an ultrathin layer of the material is deposited and, subsequently, in situ inhomogeneously etched in the TiCl4 flow, both steps being performed at a temperature above 350°C. As a result, an ultrathin microrough mixed amorphous/anatase-phase surface layer is created. By using this layer as a seed layer, the crystalline-growth temperature of the material is reduced. So anatase (mixed with amorphous phase) TiO2 thin films on SiO2 substrates at 125°C are, for the first time, grown. The films are shown to be depth-inhomogeneous. The upper part of the films, when they are thicker, is well texture

Effect of phase composition on X-ray absorption spectra of ZrO2 thin films

The X-ray photoabsorption spectra of ZrO2 films with different phase compositions were measured. The analysis of the results obtained shows that due to the site-sensitivity the X-ray photoabsorption spectroscopy is an attractive method for characterization of the ZrO2 structure. This allows application of the X-ray spectroscopy in investigation of the crystal structure in the various stages of the thin film growth including the initial stage of the ZrO2 growth. (c) 2006 Elsevier B.V. All rights reserved