Spatial Distribution of the Dislocation Trails in Silicon

Abstract

Formation of the dislocation trails (DTs) left at the slip plane behind expanding dislocation half-loops is studied in Cz-Si plastically deformed at 600°C using the selective chemical etching and the EBIC and LBIC techniques which are sensitive to the defect recombination activity. It is found that the dislocation trails are qualitatively different for the half-loops expanded from the tensile and compressed surfaces of the bent sample. In the tensile part, DTs with the strongest recombination contrast are always revealed behind the 60oarm of the half-loops, while DTs are invisible (if exits at all) behind another arm and the bottom segment. The dissimilar behavior of two differently aligned 60° segments can be related to a different fine structure of their cores. The picture of dislocation trails is found to be different in the 1020 μm surface layer that is tentatively ascribed to the near-surface bending of dislocations. In the compressed part, the EBIC and LBIC contrasts are generally smaller and the noticeable DTs are only revealed in the middle part the half-loop. Presumable reasons for the effects are discussed.