Abstract :
Atomic layer deposition of TiO2thin films from TiCl4and H2O at 1508C was found to result in nonhomogeneous film
growth as a function of time. The unevenness of the growth was ascertained by in situ optical interference technique. In
order to obtain a more detailed understanding of the growth behavior, AFM, SEM, EPMA, RHEED, XRD, and XPS
measurements were performed on a series of films of different thickness. The data obtained allow us to relate the
peculiarities of the growth to the appearance of anatase inclusions in the amorphous base layer of TiO2 followed by their
development into crystalline particles. We managed to delimit the nucleation stage of the growth, the stage of the full
coverage of the substrate with the amorphous film, the stage of the origination of the anatase inclusions, and the final stage
at which the polycrystalline film is deposited. The increase of crystallinity and roughness was correlated with the increase of
the film thickness and quantitatively determined. It was found that in our films the composition of both the crystalline and
amorphous part corresponds to TiO2 stoichiometric phase, and that the films contain 0.3 mass% of Cl. q1998 Elsevier
Science B.V. All rights reserved.
Keywords :
In situ and exsitu characterization , Atomic force microscopy AFM. , Amorphous and crystalline phases , Atomic layer epitaxy ALE. , Atomic layer deposition ALD. , TiO2 thin films
