Ohmic contact to n-type Ge with compositional Ti nitride

Abstract Fermi-Level pinning at Ge surface results in high Schottky barrier height (SBH) for nearly all metal/n-Ge contacts. By varying composition of the TiN x , modulation of the SBH was demonstrated for TiN x /n-Ge contact. The effective SBH of the TiN 0.1 /n-Ge Schottky contact was found decreased to 0.45 eV, as compared to the Ti/n-Ge contact SBH which was originally pinned at 0.56 eV. Ohmic contact to n-type Ge was realized by increasing the nitrogen composition to x = 0.8 in TiN x . Dipoles formed by the difference of the Pauling electronegativities for Ge and N at the contact interface is proposed to alleviate the Fermi-Level pinning effect.