Anomalous charge carrier transport phenomena in highly aluminum doped SiC

Abstract

Temperature dependant Hall effect measurements were performed on aluminum doped SiC samples with specific resistivities between 8 ohm cm and 0.1 ohm cm. In all samples indications for impurity conduction at low temperatures were found. In low doped samples, a sharp transition between the impurity conduction transport regime and the hole conduction regime is visible in the temperature dependence of specific resistivity, charge carrier concentration and mobility. In highly doped samples (rho < 0.2 ohm cm), this transition is no longer confined to a small temperature range and much less abrupt. We conclude that the impurity conduction is still present at high temperatures in highly aluminum doped SiC so that at least two competing transport mechanisms are present simultaneously in these samples

Bulk growth of SiC – review on advances of SiC vapor growth for improved doping and systematic study on dislocation evolution

“…Both low and high doped n-and p-type crystals were evaluated regarding basal plane dislocations. The doping concentration in both doping types was in the range n, p = 10 16 -10 19 cm -3 for the purely n-and p-type doped crystals and about 10 17 -10 18 cm -3 (p-and n-type doped regions) for the sequentially p-type/n-type/p-type doped ones as determined by optical absorption [31] and Hall measurements [32]. The seed crystals used in the growths were n-type doped (n ≈ 2 × 10 17 cm…”