4. Discussion
The experimental results reported here showtwo general features of
the TiO2 layer growth fromTDMAT and H2OALD. The first observation is
that the H2O purge times have to be increased for substrate temperatures
above 250 °C. In this temperature range, the thin film surface
changes from an amorphous TiO2 to anatase and rutile termination
and at the same time the decompositionmechanismof TDMAT changes
from surface dominated to surface plus gas phase decomposition
[33,34]. Both effects may induce changes in the deposition mechanism
and in turn of the growth rate, as compared to substrate temperatures
below 250 °C. This will be discussed in the following.
The adsorption of water on anatase surfaces takes place on two
structurally different sites and desorption from these sites takes place