Stacking faults in intrinsic and N-doped 4H-SiC: True influence of the N-doping on their multiplicity

摘要

The stacking fault multiplicity was studied in intrinsic and N-doped (0001) 4H-SiC. The defects, nucleated by a scratch on the sample surface, expanded during annealing at 973 K. The stacking width was determined by high-resolution transmission electron microscopy. In both materials, the double stacking faults (DSF) are the most numerous defects. Multiple faults, rare, consist of two, three or four successive DSFs. Single stacking faults or odd numbers of stacking faults are never observed. Thus, the α-β phase transformation has little influence on the fault creation and even in N-doped 4H-SiC, the quantum well action only helps the expansion of the DSFs, the already most favourable defects.