Solutal convection in garnet liquid-phase epitaxy using vertical dipping

In the vertical dipping procedure for the LPE of garnets, the growth process will cause a horizontal concentration gradient and with that a density gradient in the fluid near the growing interface. This results in a downward flow along the wafer, making the garnet film thicker at the upper part of the wafer than near the lower part. A mathematical description of this type of flow and its effect on the growth kinetics is given. Comparison with experimental data shows that the observed phenomena can be explained on the basis of this type of convection. Because this flow arises due to the growth process itself, it cannot be avoided and vertical dipping seems therefore less suitable for the production of films of uniform thickness.