MEASUREMENT OF THE HALL SCATTERING FACTOR IN 4H AND 6H SIC EPILAYERS FROM 40 TO 290 K AND IN MAGNETIC-FIELDS UP TO 9 T

The Hall scattering coefficient r(H) determines the relationship betwe en the measurable Hall coefficient R-H and the free carrier concentrat ion. Reliable knowledge of r(H) is necessary for the precise interpret ation of Hall measurements and to validate theoretical transport calcu lations. We have measured the Hall scattering factor in nitrogen doped 4H and 6H epitaxial layers from 35 to 290 K in magnetic fields up to 9 T. The effective Hall scattering factor varies between 0.91 and 1.21 in 4H SiC and 0.84 and 1.02 in 6H SiC. The effect of the Hall scatter ing factor on dopant activation energies obtained from Hall measuremen ts is not large enough to explain the difference between dopant activa tion energies obtained from Hall effect and infrared absorption measur ements. (C) 1998 American Institute of Physics. [S0021-8979(98)01516-3 ].