Experimental study of grain boundary orientations in multi-crystalline silicon

Abstract Some peculiarities of straight and zig-zag grain boundaries in multi-crystalline Si ingots were analyzed by Scanning Electron Microscopy-Electron BackScatter Diffraction (SEM-EBSD) and Three Dimensional (3D) grain boundary reconstruction. In the cases where straight grain boundaries were perpendicular to facing {111} planes in the two neighboring grains, they were found parallel, within the measurement accuracy, to the bisector of the two facing {111} planes. This is in agreement with the theory predicting the existence of Facetted–Facetted grooves during the growth of multicrystalline Si. Another grain boundary was corresponding to the predicted Facetted–Rough groove. It was found that the zig-zag grain boundaries were successively composed of {111} twin planes and ( 4 ¯ 11 ) / ( 011 ) planes, so that the two grains are always in Σ3 relationship. The phenomenon leading to the formation mechanism for these boundaries remains a subject for research.