Temperature-dependent Hall mobility in heavily Al-doped 4H-SiC grown by chemical vapor deposition

Abstract The temperature-dependent Hall mobilities ( μ Hall ( T )) of heavily Al-doped 4H-SiC, fabricated using chemical vapor deposition with Al concentrations ( C Al ) exceeding 10 19 cm −3 , are analyzed to develop p + -type substrates suitable as collectors for n-channel insulated-gate bipolar transistors. In the band conduction region, the μ Hall ( T ) in the valence band is governed by acoustic phonon scattering at high temperatures and ionized impurity scattering at low temperatures. The μ Hall ( T ) in the allowed miniband formed by the first excited states of Al acceptors falls within the lower half of the 10 −1 cm 2 V −1 s −1 range. In the nearest-neighbor hopping conduction region, the μ Hall ( T ) is around 0.1 cm 2 V −1 s −1 and increases with increasing T .