Mathematical Modelling of the Liquid Encapsulated Czochralski Growth of Gallium Arsenide. Part I-Stress model

C. E. SCHVEZOV; I. V. SAMARASEKERA; F. WEINBERG

JOURNAL OF CRYSTAL GROWTH

Published by Elsevier Science Publishers B.V. (North Holland Physics Publishing Division

Lugar: Sara Burgerhartstraat 25. 1055 KV Amsterdam. Netherlands.; Año: 1987 vol. 84 p. 219 - 230

0022-0248

The stress distribution in GaAs crystals, during growth, has been calculated with finite element numerical methods, assuming thermoelastic crystal ehaviour. These results are compared to analytical solutions and found to be in good agreement with axisymmetric solutions, and to a lesser extent with plain strain solutions. Based on calculated thermal stresses in the crystal, the Von Mises stresses have been detemined by substracting reported values of the yield stress and critical resolved shear stress from the maximum resolved shear stress. The results show high dislocation densities occur in the central region and near the outside surface of the crystal in agreement with reported observations of etch pit density distributions in GaAs.