Anisotropy of the electron Hall mobility in 4H, 6H, and 15R silicon carbide

Hall effect measurements in a Hall-bar configuration are performed on nitrogen-doped n-type bulk 4H, 6H, and 15R SiC single crystals cut into small parallelepipeds with their longest edges either parallel or perpendicular to the ĉ axis. In the temperature range investigated (40–700 K), an anisotropy of the electron Hall mobility is observed in all three polytypes. While the mobility perpendicular to the ĉ axis—with magnetic field perpendicular or parallel to the ĉ axis—is greater than the mobility parallel to the ĉ axis for 6H and 15R SiC, 4H SiC shows the opposite behavior.