Depth carrier profiling in silicon carbide

The measurement of majority carrier concentration profiles in silicon carbide is critically discussed considering the most promising methods. Three different techniques are reviewed in detail: (1) capacitance–voltage measurements, (2) scanning capacitance microscopy and (3) spreading resistance profiling. The potentialities and the limitations of these methods are described and compared. The investigated samples include p- and n-type epitaxial layers with a doping concentration in the range 1016–1019 cm−3 and ion implanted samples at several doses. The applications of spreading resistance profiling and scanning capacitance microscopy in p- and n-type implanted samples are shown both for uniformly doped samples and single implantation profile. The carrier profiles measured by scanning capacitance microscopy can be quantified by calculations of a complete set of capacitance–voltage curves. Difficulties are presented when quantitative carrier concentration profiles should be calculated by the spreading resistance measurements.