X-ray topographic observation of dislocation generation and propagation in InP single crystal grown by the liquid-encapsulated Czochralski technique

Abstract

Dislocation generation and propagation in InP single crystals grown in the [1̄1̄1̄] direction by the liquid-encapsulated Czochralski (LEC) technique have been studied by means of x-ray diffraction topography. First, the type of dislocations propagating from the seed crystal towards the grown crystal is determined, and the effect of using a necking-in procedure is described. Burgers vector determination indicates that the dislocations are of a sessile type and propagate along the 〈1̄1̄0〉 direction, with the Burgers vector parallel to the 〈11̄0〉 direction. Secondly, the propagation of dislocations that nucleate at the crystal surface during crystal growing is described. It is observed that the dislocations propagate by glide on three oblique downward pointing {111} slip planes, which are inclined in the [1̄1̄1̄] growth direction. A mechanism responsible for the high dislocation densities of crystals grown by the LEC technique is discussed.