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 1e16 -
1e19 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.