Analysis of reverse current–voltage characteristics of Ti/6H–SiC Schottky diodes

Investigations on electrical properties of as fabricated and annealed titanium 6H–SiC Schottky contacts were performed by current–voltage (I–V) and capacitance–voltage (C–V) measurements in a temperature range of 100–460 K. Both the Schottky barrier height (SBH) Φb and the ideality factor n were found to depend on temperature and voltage. In addition, a systematic discrepancy between barrier heights extracted from I–V and C–V curves was observed. An explanation is given for the high leakage currents which are still a general problem of SiC Schottky diodes. On the basis of two analytical models we are able to describe this behavior assuming the formation of a very thin inhomogeneous interfacial layer between metal and semiconductor.