Mathematical modeling of impurity distribution in the melt meniscus in the growth of profiled sapphire crystals

The distribution of impurities in the growth of profiled sapphire crystals is simulated. The distribution of impurities was calculated with the use of the diffusion equation with convective terms. The melt flow was found by solving the Navier-Stokes equation. The distributions of impurities over the melt meniscus are obtained at different crystallization rates. The maximum concentration supersaturation in the meniscus is studied as a function of its geometric parameters.     

Algorithm for crystal-profile control in automated crystal growth by the Czochralski method

Growth setups of the new generation should provide crystal growth in the automated mode. One of the necessary conditions for growing quality crystals is the rigorous maintenance of the given boule profile. In the systems with weight control, the model weight is compared with the weight measured by the weight sensor. Below, we describe an algorithm for calculating the model weight based on the numerical solution of the Bardsley equation. The algorithm allows one to set the crystal profile either by a function or a point set.     

Study of the effect of crystallization parameters on gaseous inclusions in sapphire ribbons grown by the Stepanov method

Crystallography Reports - The effect of growth parameters on the two main types of gaseous inclusions in sapphire ribbons—bubbles in the crystal bulk and near-surface pores—have been...