The characteristics of interfacial reactions and the valence band offset of HfO2 films grown on GaAs by atomic layer deposition were investigated by combining high-resolution x-ray photoelectron spectroscopy and high-resolution electron transmission microscopy. The interfacial characteristics are significantly dependent on the surface state of the GaAs substrate. Polycrystalline HfO2 film on a clean GaAs surface was changed to a well-ordered crystalline film as the annealing temperature increased, and a clean interface with no interfacial layer formed at temperatures above 600 °C. The valence band offset of the film grown on the oxidized GaAs surface gradually increased with the stoichiometric change in the interfacial layer.
Bibliographical noteFunding Information:
This work is partially supported by the “IT R&D program of MKE/IITA (2008-F-023-01, next generation future device fabricated by using nano junction)” and by the “System IC 2010 project of the Korea Ministry of Science and Technology and Ministry of Commerce, Industry and Energy.”
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)