Modulation of WN_x/Ge Schottky barrier height by varying N composition of tungsten nitride

Modulation of the Schottky barrier heights was successfully demonstrated for WN_x/p-Ge and WN_x/n-Ge contacts by increasing the nitrogen component in the WN_x films. The WN_0.38/p-Ge contact exhibits rectifying characteristic and an apparent Schottky barrier of 0.49 eV while the WN_0.38/n-Ge Schottky contact exhibits quasi-Ohmic current–voltage characteristics. Dipoles formed at the contact interface by the difference of the Pauling electronegativities of Ge and N are confirmed to alleviate the Fermi-level pinning effect.