Institution: | a Institute of Physics, University of Tartu, Tähe 4, 51010, Tartu, Estonia b Institute of Physical Chemistry, University of Tartu, Jakobi 2, 51013, Tartu, Estonia |
Abstract: | Atomic layer deposition of hafnium dioxide (HfO2) on silicon substrates was studied. It was revealed that due to low adsorption probability of HfCl4 on silicon substrates at higher temperatures (450–600 °C) the growth was non-uniform and markedly hindered in the initial stage of the HfCl4–H2O process. In the HfI4–H2O and HfI4–O2 processes, uniform growth with acceptable rate was obtained from the beginning of deposition. As a result, the HfI4–H2O and HfI4–O2 processes allowed deposition of smoother, more homogeneous and denser films than the HfCl4–H2O process did. The crystal structure developed, however, faster at the beginning of the HfCl4–H2O process. |