Growth of epitaxial TiN films on MgO(100) by high current discharge plasma

Abstract

High current discharge plasma produced by the Ta-LaB6 cathode was used for ion plating of TiN films. The dependence of the deposition rate of TiN on the substrate dc bias potential was measured using the Rutherford backscattering spectrometry (RBS) method. The results indicate that the particles impinging on the substrate, i.e., vaporized particles (Ti) and reactive gases (N2), could be ionized at high efficiency of 70%. Epitaxial TiN films were grown at temperatures between 400 and 700 °C on cleaved MgO(100) substrate supplied with negative dc anf rf potential. Structures of the epitaxial film were investigated by RBS and ion channeling, and scanning tunneling microscope (STM). The minimum channeling yields for (100) and (110) axes obtained at a substrate temperature of 550 °C with the growth rate of 40 Å/s were found to be 1.4% and 2.0%, respectively, which were almost the same as that of the MgO substrate. Atomically resolved tunneling images of (100) surface of the epitaxial TiN film were observed by STM.