Fabrication and electrical characterization of NbN-interfacial layer-Si contact diodes

Nb and NbN-SiO/sub 2/-Si Schottky contact diodes were fabricated on chemically cleaned Si substrates by RF magnetron sputtering in Ar and Ar-N/sub 2/ ambients, respectively. The electrical behavior of the contact diodes was investigated by current-voltage and capacitance-voltage measurements over the temperature range of 10 to 300 K. The Nb contact diodes fabricated on p-type Si substrates have good Schottky barrier diode behavior. The NbN Schottky diodes on both n-type and p-type substrates exhibited lower quality behavior than their Nb counterparts. The electrical measurements have determined the barrier height of both the Nb-Si and NbN-Si systems. The low-temperature characterization yielded lower diffusion potentials than predicted by the theory of F.A. Padovani and R. Stratton (1966).