A study was made of the effect of substrate orientation namely (11▪0) and (00▪1) oriented crystals on defect formation in 4H-SiC. The microstructure of the various samples, as-implanted with P and annealed, were studied by Rutherford back-scattering spectrometry and channelling and transmission electron microscopy in an attempt to understand the damage evolution and defect structures resulting from different crystal orientations and different implantation damage. The annealing of the damage resulted in a range of different defects including dislocation loops, voids and precipitates in both a-cut and c-cut crystals. For c-cut crystals, the formation was observed of the Frank prismatic (00▪1) loops previously reported in implanted SiC, and of 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 was noted of 2 types of dislocation loop, 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 have a (11▪0) habit plane, and could be a larger variant of the (11▪0) prismatic loops, were also observed in the a-cut sample. Small precipitates were observed, pinned to these loops. 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 (00▪1) 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)