Growth of epitaxial TiN thin films on Si(100) by reactive magnetron sputtering

Abstract

Growth temperature was found to play a crucial role in determining the structure of stoichiometric TiN films deposited on Si(100) by reactive magnetron sputtering. X-ray diffraction, transmission electron microscopy (TEM), and reflection high-energy electron diffraction were used to show that films deposited at substrate temperatures Ts ranging from 700 to 1100 °C were polycrystalline, with either (100) preferred orientation or mixed (100) and (111) orientations. Films deposited using a two-temperature technique were epitaxial with the relationships TiN(100)//Si(100) and TiN[011]//Si[011] but with considerable misorientation. The most highly oriented films were obtained when 45 nm was first deposited at Ts =750 °C, followed by 250 nm at 1000 °C. High-resolution cross-sectional TEM studies showed that increasing the nucleation temperature above 750 °C led to random orientation of TiN lattice fringes relative to the Si lattice. This was explained by the small energy difference between oriented and misoriented TiN nuclei due to the large lattice mismatch (22%).