Local Capacitance-Voltage Profiling and Deep Level Transient Spectroscopy of SiO2/SiC Interfaces by Scanning Nonlinear Dielectric Microscopy

In order to investigate the nanoscale spatial details of SiO
2
/SiC interfaces, we propose local capacitance-voltage and its voltage-derivative characteristics measurement technique using a recently developed time-resolved scanning nonlinear dielectric microscopy setup. Our technique can be combined with local deep level transient spectroscopy based on the same setup for the imaging of spatial distribution of interface defect density. Here we apply the developed technique to SiO
2
/SiC interfaces to investigate the effects of the nitridation treatment. We find that the nitridation significantly reduces hysteresis in individual local capacitance-voltage characteristics and also suppresses their spatial fluctuations. On the other hand, the significant spatial fluctuations remain ever after nitridation, which might suggest the existence of intrinsic non-uniformity at the SiO
2
/SiC interfaces.