The Effect of Crystal Radius Fluctuations on the Stress Field in LEC Gallium Arsenide

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. 85 p. 142 - 147

0022-0248

Calculation of shear stress field in LEC Gallium Arsenide have been carried out in which the crystal radius was systematically changed during growth. Varius combinations of wavelength and amplitude fluctuations were considered both in the bulk crystal and the seeding cone. For the bulk crystal, the maximum shear stress is shown to increase as the amplitude of the fluctuations increases and the wavelength decreases. For fluctuations with wavelengths less than 20 mm, the shear stress increases hyperbolicallly with decreasing wavelength. Fluctuations in radius in the seeding cone result in higher stresses in the cone, but these stresses do not reach the stresses in the bulk crystal.