Czochralski growth of bulk crystals of Ge1-xSix alloys

Bulk crystals of Ge1-xSix alloys in the composition range of 0 < x < 0.89 were grown by the Czochralski method. Fully or partly grown single crystals were obtained, depending on the melt composition. The compositions of grown crystals were determined by means of energy dispersive X-ray (EDX) spectroscopy and grown-in defects were observed by etch pit and X-ray topographic techniques. The variations of the compositions along the growth direction in the crystals were discussed. The gravity effect in the melt caused by a large difference in the densities of Ge and Si was deduced.