The correlations between the cell dimension, d, of characteristic dislocation cell patterns and acting thermo-elastic stress, τ, during the growth of 6-inch semi-insulating VCz and VGF GaAs crystals were considered. Whereas the dislocation density and cells were analysed experimentally, the history of the elastic stress, responsible for cell formation, was obtained by global numerical calculations. At stresses below 1MPa, diffusion-controlled creep was the predominant mechanism of dislocation motion. Different d(τ) - proportionalities in VCz and VGF crystals were determined. This was due to the varying thermal conditions and resting times of the growing crystal at high temperatures.

Studies on Dislocation Patterning in 6-Inch GaAs Crystals, P.Rudolph, C.Frank-Rotsch, U.Juda, S.Eichler, M.Scheffer-Czygan: Physica Status Solidi C, 2007, 4[8], 2934-9