Surface potential fluctuations in metal–oxide–semiconductor capacitors fabricated on different silicon carbide polytypes

Abstract

The standard deviation σs of the surface potential fluctuations affecting metal–oxide–silicon carbide capacitors has been extracted from low frequency conductance and capacitance measurements. These fluctuations may become very large for thermal oxides and aluminum-doped epilayers. They must induce large errors in usual metal–oxide–semiconductor characterization techniques and are most probably the main reason for observing an activated transport in silicon carbide inversion layers.