Epitaxial growth of Co-doped rutile TiO2 films on TiN buffered silicon

摘要

Cobalt-doped TiO2 has been actively investigated for the spintronic applications owing to its high Curie temperature and the presence of n-type electrical behavior. Up to date, oxide-based substrates have been employed for the epitaxial growth of Co-doped TiO2 films. For example, SrTiO3 and LaAlO3 have been used for anatase and Al2O3 for rutile phase stabilization. However, heteroepitaxial growth of a ferromagnetic semiconductor on silicon substrate is of great interest due to potential applications on a basis of advanced silicon microelectronics technology. We report the integration of an epitaxial Co-doped rutile TiO2 film into silicon which has been achieved using a TiN buffer layer. TiN is known to be thermodynamically stable in contact with silicon and provides an excellent template for the overgrowing Co-doped TiO2 through in situ oxidation.