Problems, prospects, and alternatives for semiconductor single crystal growth in space

Abstract

Experimental results for growing semiconductor single crystals under real microgravitation conditions aboard spacecraft have been analyzed. The causes for the formation of dopant distribution micro- and macroinhomogeneities in crystals have been studied. It has been shown that it is necessary to provide diffusion heat and mass transfer conditions in a melt to achieve a high homogeneity of properties in grown crystals. These conditions and expected optimal parameters of crystals can be obtained in the absence of thermogravitational convection, when a free surface of the melt is eliminated, and also under conditions of minimizing external quasi-static effects on the melt causing forced convective flows in them and, correspondingly, inhomogeneity of composition and properties for grown crystals due to the increasing gravitational sensibility of melts under microgravitation conditions.