Heteroepitaxial structures of SrTiO3/TiN on Si(100) by in situ pulsed laser deposition

High-quality ceramics based heteroepitaxial structures of oxide-nitride-semiconductors, i.e., SrTiO3/TiN/Si(100) have been fabricated by in situ pulsed laser deposition. The dependence of substrate temperature and oxygen partial pressure on the crystalline quality of the SrTiO3 films on Si with epitaxial TiN template has been examined. We found that epitaxial growth occurs on TiN/Si(100) above 500 degree C, initially at a reduced O2 pressure (10-6 Torr), and followed by a deposition in the range of 5 endash 10x10-4 Torr. X-ray diffraction (Θ, ω, and Φ scans) and transmission electron microscope (TEM) results revealed an excellent alignment of SrTiO3 and TiN films on Si(100) with a cube-on-cube epitaxy. Rutherford backscattering and ion channeling results show a channeling minimum yield (χmin) of ∼13% for the SrTiO3 films. High-resolution TEM results on the SrTiO3/TiN interface show that the epitaxial SrTiO3 film is separated from the TiN by an uniform 80 endash 90 A crystalline interposing layer presumably of TiNxO1-x (oxy-nitride). The SrTiO3 film fabricated at 700 degree C showed a high relative dielectric constant of 312 at the frequency of 1 MHz. The electrical resistivity and the breakdown field of the SrTiO3 films were more than 5x1012 Ωcm and 6x105 Vcm-1, respectively. An estimated leakage current density measured at an electric field of 5x105 V/cm-1 was less than 10-7 A/cm2. copyright 1996 American Institute of Physics