A comparison of extended defect formation induced by ion implantation in (0 0 0 1) and (1 1 2̄ 0) 4H-SiC

We study the effect of substrate orientation on defect formation in 4H-SiC. Both (112̄0) and (0001) n-type 4H-SiC substrates were implanted with 400 keV P. The various samples, both as-implanted samples and annealed, were studied by Rutherford backscattering and channeling and transmission electron microscopy in an attempt to understand the damage evolution and defect structures resulting from different crystal orientations. Secondary ion mass spectrometry (SIMS) was performed for P elemental profiling before and after annealing. We observe a significantly different damage accumulation in the two directions with a broader amorphous layer formed in the c-cut crystal compared to the a-cut crystal. The annealing of the damage results in a range of different defects including dislocation loops and voids in both a-cut and c-cut crystals. The SIMS profiles show in some cases distinct differences between the two crystal directions.