Numerical analysis of the dissolution process of GaSb into InSb melt under different gravity conditions

In order to support the process of growth of high-quality InGaSb single crystals, a numerical simulation has been carried out to clarify effects of temperature gradient, heating rate, and gravity level during the dissolution process. A sandwich model of GaSb/InSb/GaSb combination has been used, where GaSb is in solid state and InSb is in molten state at the start of calculation. The amount of GaSb dissolved into the InSb melt decreased and the solid-liquid interface changed from asymmetric to symmetric shape with increase of temperature gradient. The dissolved amount decreased with increased heating rate without holding of temperature. However, holding process increased dissolution. The combination of high heating rate and holding of temperature was more suitable than stable heating with a low heating rate to achieve steady state in a shorter time. The shape of the solid-liquid interface was strongly distorted under I G condition, but it became flat and iso-concentration lines became parallel to the interface as the gravity level was reduced. (C) 2002 Elsevier Science B.V. All rights reserved.