  In this work, we report on the addition of GeH4 gas during homoepitaxial
growth of 4H-SiC by chemical vapour deposition. Ge introduction does not affect
dramatically the surface morphology and defect density though it is accompanied
with Ge droplets accumulation at the surface. The Ge incorporation level inside
the 4H-SiC matrix, ranging from few 1017 to few 1018 at.cm-3, was found to be
mainly affected by the growth temperature and GeH4 flux. Other growth
parameters like C/Si ratio, polarity, or off-orientation did not show any
significant influence. On the other hand, adding GeH4 led to the increase of
the intentional n type doping level by a factor of 2 to 5 depending on the C/Si
ratio in the gas phase.
