The effect of substrate orientation, (11▪0) and (00▪1), upon defect formation in 4H-SiC was studied. The microstructure of the various samples, as-implanted with P and annealed, were studied by Rutherford back-scattering spectrometry and channeling and transmission electron microscopy in an attempt to understand the damage evolution and defect structures resulting from different crystal orientations and different implantation damage. Annealing of the damage resulted in a range of defects including dislocation loops, voids and precipitates in both a-cut and c-cut crystals. For c-cut crystals, the formation of Frank prismatic (00▪1) loops previously reported in implanted SiC, was observed plus a second type of defect which exhibited a stacking fault contrast which was consistent with pure Shockley partials and/or (00▪1) sheared interstitial defects bounded by a Shockley partial dislocation. A mechanism for the formation of the latter defects in SiC was proposed and the relative stacking fault energies of the proposed defects were estimated by using calculated parameters for the axial next-nearest neighbor Ising spin model. For the a-cut crystal, the presence of 2 types of dislocation loops was noted, with 2 habit planes. These were small dislocation loops located on the basal plane (00▪1) and large (11▪0) prismatic loops. In addition, larger conglomerated loops which did not necessarily had a (11▪0) habit plane and could be a larger variant of the (11▪0) prismatic loops were also observed in a-cut samples. Small precipitates were observed to be pinned to these loops. Elemental profiling of the implanted species before and after annealing by secondary ion mass spectrometry revealed a correlation between precipitation close to dislocation networks and the agglomeration of P at certain depths.

Ion-Implantation-Induced Extended Defect Formation in (0001) and (11▪0) 4H-SiC. J.Wong-Leung, M.K.Linnarsson, B.G.Svensson, D.J.H.Cockayne: Physical Review B, 2005, 71[16], 165210 (13pp)