Temperature dependence of friction force acting on dislocations in silicon crystals

Abstract

The characteristics of the dislocation motion in silicon crystals during annealing have been investigated by means ofin situ X-ray topographic observations in the temperature range from 1173 to 1273 K. When annealed at elevated temperatures, the small displacements in position of the dislocation segments took place so as to balance the friction force acting on these segments with the elastic interaction force between dislocations. From the analysis of (i) repulsive interaction between parallel screw dislocations with the same sign, and of (ii) configurational changes of dislocation half-loops, the friction force acting on dislocations can be determined at each annealing temperature by estimating the repulsive interaction force between parallel dislocations, and the force due to line tension for curved dislocation. On the basis of the analysis of the temperature dependence of friction force, the activation energy for dislocation motion is evaluated to be 2.4 eV for a screw dislocation and 2.2 eV for a 60° dislocation.