Oxygen precipitation and the generation of dislocations in silicon

Abstract

Oxygen-rich precipitates in silicon, and the generation of dislocations at the interfaces between the precipitates and the matrix were observed. The precipitates are square-shaped plates with ⟨110⟩ sides and {100} habit planes. Prismatic dislocation loops are generated in silicon by the mechanism of prismatic punching. The loops are identified as interstitial loops with ½ ⟨110⟩ Burgers vectors and ⟨110⟩ axis. An ideal loop is rhombus-shaped with line senses in ⟨112⟩ directions. Nucleation of loops follows the mechanism of Ashby and Johnson (1969): a shear loop is nucleated on an initial slip plane and completes a rhombus-shaped prismatic loop by repeated cross-slips. To our knowledge, the loop nucleation process is identified for the first time for a system completely under internal stress.