Electrical transport properties of p-type 4H-SiC

Abstract

The Hall hole density pH and Hall mobility μH in highly aluminum-doped 4H-SiC have been investigated in the wide temperature range between 100 and 900 K. After an overview of the literature data related to the analysis of electrical transport experiments, a model taking into account the two uppermost valence bands of heavy and lights holes, one single acceptor energy EA and the empirical Hall factor rHexp has been discussed in details. The limits of the applied model as a function of temperature and acceptor concentration have been considered. For each analyzed sample, the acceptor density NA and the compensation ratio ND/NA have been experimentally assessed by capacitance–voltage and secondary ion mass spectroscopy measurements. Finally, the Hall carrier concentration vs. doping level NA−ND as well as ionization energy of acceptor EA vs. acceptor concentration NA in 4H-SiC have been discussed.