Analysis of the practical stability of dewetted Bridgman growth of GaAs.
Résumé
Due to large scale applications the crystal growth technology of gallium arsenide has made considerable progress but there is still a need for improving the crystal size and quality. The study of practical stability of GaAs crystals that could be grown by the dewetted Bridgman process [1] is presented. According to the analytical and numerical investigations of the dynamic stability of the dewetted Bridgman process reported in [2-3], a range of acceptable maximal and minimal crystal radius is given and fluctuations of the gas pressure are introduced in the system. It is shown that only certain frequencies and amplitudes of these fluctuations lead to stable growth in the case of a globally convex meniscus (theta(c) + alpha(e) >= 180 degrees). When theta(c) + alpha(e) < 180 degrees the growth is always unstable. Examples of stable and unstable growth are given for the case of industrial production.