Barrier height reduction to 0.15eV and contact resistivity reduction to 9.1×10−9 Ω-cm2 using ultrathin TiO2−x interlayer between metal and silicon

Metal-insulator-Si (MIS) tunnel contact is studied using ultrathin, non-stoichiometric TiO<sub>2-x</sub> interlayer on n<sup>-</sup> and n<sup>+</sup> Si. Systematic analysis indicates a record low Schottky barrier height (SBH) of 0.15eV for Ti metal using 10A thick TiO<sub>2-x</sub> interlayer (T<sub>Ins</sub>). Ti/TiO<sub>2-x</sub>/n<sup>+</sup> Si contact achieves a record low specific contact resistivity (ρ<sub>c</sub>) of 9.1×10<sup>-9</sup>Ω-cm<sup>2</sup>.The modeling of ρ<sub>c</sub> suggests tunneling mass, m*<sub>Tunnel</sub>, of 0.7m<sub>0</sub> for TiO<sub>2-x</sub> compared to stoichiometric TiO<sub>2</sub> indicating transition from an insulator to a wide gap semiconductor.