Анотація:
Semiconductor compounds are now and in future of central importance for human life. A relatively high degree of production maturity has been already achieved. GaAs holds a leading position for opto- and high-frequency microelectronics that will be continuously developed further. Single crystalline yield of InP, GaSb, CdTe and ZnO needs to increase essentially. For all these compounds the growth from melt by vertical gradient freeze is of raising relevance. High growth rates are expected for GaN and AIN. Accordingly, the mastering of the vapour-solid and flux-solid phase transitions on higher technological level is absolutely necessary. Despite of great efforts during the last decade there are some fundamental difficulties to be still solved even for the melt growth, such as overcoming of melt structuring, damping of convective perturbations, in-situ control of stoichiometry, minimization of precipitation, reduction of dislocation patterning, depression of twinning and installation of model-based control systems of the growth processes. The author gives an overview on possible measures being under development in his team and at Institute for Crystal Growth (Berlin) in order to meet these goals.