Materials Science Forum, Vol.457-460, 719-722, 2004
Uniform axial charge carrier concentration in PVT-grown p-type 6H SiC by non-uniform distribution of boron in the powder source
We have investigated the influence of boron distribution within the powder source during PVT growth of p-type 6H-SiC on the axial homogeneity of the charge carrier concentration. It is shown that a rather homogeneous hole concentration in the grown crystals can be achieved if the boron doped portion of the powder is located at the upper crucible part due to the compensation with nitrogen. In this case a simultaneous decrease of N-A and N-D concentration is observed during growth. Homogeneity with respect to the optical absorption in the visible was also achieved.