Convection in melts and impurity distribution in semiconductor crystals

Impurity distributions in semiconductor melts and crystals grown from these melts ore experimentally and numerically studied on an example of Ga-doped Ge crystals. It is shown that inhomogeneous dopant distribution is observed in the form of striations and is caused by the convective flows in the melt and their nonstationary rearrangement in the vicinity of the crystallization front. The character of heat and mass transfer under the microgravity conditions is predicted. The necessity of precision experiments under terrestrial and, especially, space conditions is emphasized. (C) 2000 MAIK "Nauka/Interperiodica".