The atomic layer deposition (ALD) of TiO2 fromtetrakis(dimethylamino)titanium (TDMAT) and waterwas studied
in the substrate temperature (TS) range of 120 °C to 330 °C.
The effect of deposition temperatures on the resulting layer microstructure is investigated. Based on the experimental
results, possible interaction mechanisms of TDMAT and H2O precursor molecules and the TiO2 surface
at different temperatures are discussed. The TiO2 layers were characterized with respect to microstructure, composition
and optical properties by glancing angle x-ray diffraction and reflectometry, x-ray fluorescence analysis,
photoelectron spectroscopy and spectroscopic ellipsometry. A constant layer growth with increasing number of
ALD cycles was achieved for all investigated deposition temperatures, if the inert gas purge time after the H2O
pulse was increased from 5 s at temperatures below 250 °C to 25 s for TS ≥ 320 °C. In the investigated temperature
range, the growth per cycle varies between 0.33 and 0.67 Å/cycle with a minimum at 250 °C.
The variations of the deposition rate are related to a change froma surface determined decomposition of TDMAT
to a gas phase decomposition route above 250 °C. At the same temperature, the microstructure of the TiO2 layers
changes from amorphous to predominately crystalline, where both anatase and rutile are present.