Photoelectrochemical capacitance-voltage (PC-V) measurements have been successfully made on 4H-SiC material. The 0.05 M KOH
solution used as a Schottky contact etches the material with an average roughness of about one percent of the total average
etch depth at an etch rate of 1 µm/h. This capability allows the carrier concentration profile of thicker layers with different
doping levels to be analyzed. The PC-V measurements are compared with secondary ion mass spectroscopy. The results show agreement
with nitrogen doping in the top epitaxial layer and in the substrate. The PC-V measurement also sees an unknown species diffusing
out of the substrate into the nominally undoped buffer layer.
Key words 4H-SiC - photoelectrochemical capacitance-voltage (PC-V) measurements - secondary ion mass spectroscopy (SIMS)