Local and global simulations of Bridgman and liquid-encapsulated Czochralski crystal growth

A curvilinear finite volume-based numerical methodology has been developed that can be effectively used for simulation of the Bridgman and Czochralski (Cz) crystal growth processes. New features of grid generation have been d evised and added to the original formulation (Zhang et at, 1995, 1996) to m ake it suitable for global modeling. The numerical model can account for co nvection in both the melt and the gas phases, convection/radiation in the f urnace, and conduction in all solid components. Results for Bridgman growth show that the pow pattern and interface shape strongly depend on thermal c onductivities of the crystal, melt, and ampoule materials. Transient simula tions have been performed for the growth of Bismuth crystal in a Bridgman-S tockbarger system and the growth of GaAs crystal using liquid-encapsulated Czochralski (LEC) technique. This is the first time that a global high-pres sure LEC model is able to account for convective flows and heat transfer an d predict the interface shape and its dynamics.