30° Si(g) partial dislocation mobility in nitrogen-doped 4H-SiC

Well-controlled population of dislocations are introduced in 4H-SiC by bending in cantilever mode and annealing between 400 and 700 degrees C. The introduced defects consist of double stacking faults, each bound by a pair of 30 degrees Si(g) partial dislocations, and the expansion of which is asymmetric. The velocity of each individual 30 degrees Si(g) pair is directly measured as a function of stress and temperature on the surface of samples etched after deformation. The activation energies of the 30 degrees Si(g) partial dislocation pairs are strongly stress dependent, ranging between 1.25 and 1.7 eV. These values are lower than the ones derived from plasticity experiments. This is probably because 30 degrees Si(g) pairs and double stacking faults are generated in N-doped 4H-SiC (N=2x10(18) cm(-3)), with their development being promoted by quantum well action. (c) 2007 American Institute of Physics.