Temperature-dependent Hall effect measurements in low-compensated p-type 4H-SiC

P-type 4H-SiC substrates grown by high temperature chemical vapour deposition with doping concentration in the range of 10(17) cm(-3) to 10(19) cm(-3) have been characterised by temperature-dependent Hall effect. The study has been performed in the temperature interval from 100 K to 850 K using the Van-der-Pauw method. Low resistivity of 3.57 Omegacm to 0.45 Omegacm, depending on the concentration, is obtained at 300 K. It decreases to 1.98 - 0.14 Omegacm, respectively at 600 K. The concentration N-A and the ionisation energy DeltaE(A) Of the Al-acceptors, as well as the concentration of the compensating donors N-D have been determined taking into account the temperature dependence of the Hall scattering factor. The compensation ratio N-D/N-A varies from I to 14 % for the different samples. The Al ionisation energy decreases slightly from 200 meV to 185 meV with increase of Al doping concentration. The highest value of the hole mobility, 217 cm(2)V(-1)s(-1), is obtained at 130 K for the sample with Al-acceptor concentration of 2.50x10(17) cm(-3).