Crystal growth in the process of modified Czochralski

F. Mokhtari¹ - A. Bouabdallah¹ - M. Zizi¹ - A. Alemany²

¹ Laboratory of Thermodynamics and Energetical Systems/USTHB BP32 El Alia Bab Ezzouar, Alger
² Laboratoire des Ecoulements Geophysiques et Industriels, Grenoble, France

Abstract
Basing on the phenomenon of crystal growth in a cylindrical system, one proposes an alternative of this process, which is based on the modification of the crucible. This one is replaced by a sphere containing the molten phase of possibly variable material height, the cylinder, carrying the germ of the crystal, remains unchanged. This work is thus justified by the study of the influence of the geometry for purposes to optimize the processes of transfer in action making it possible to homogenize the field of temperature and to minimize the losses of masses having to take part in the development of the bulk-flow (the traditional Czochralski process). The simulation of the phenomenon thus defined is considered in the framework of the Boussinesq approximation to solve the equations of mass, heat, and momentum transfer written in a spherical frame of reference. By means of theoritical approach as the Galerkin Method, the objective is to determine the whole process of transfer in order to optimize the fields of temperature and velocity in the alternative CZ-process. Figs 12, Refs 29.