  We report on sexithiophene films, about 150nm thick, grown by thermal
evaporation on single crystal oxides and, as comparison, on Si/SiO2. By heating
the entire deposition chamber at 100 C we obtain standing-up oriented molecules
all over the bulk thickness. Surface morphology shows step-like islands, each
step being only one monolayer height. The constant and uniform warming of the
molecules obtained by heating the entire deposition chamber allows a stable
diffusion-limited growth process. Therefore, the regular growth kinetic is
preserved when increasing the thickness of the film. Electrical measurements on
differently structured films evidence the impact of the inter island separation
region size on the main charge transport parameters.
