Growth of 2 inch Si0.5Ge0.5 bulk single crystals

Two inch homogeneous Si0.5Ge0.5 bulk single crystals were grown by the traveling liquidus zone (TLZ) method for fabricating substrates for strained Si and strained Ge devices. The concentration variation was less than 1% for the whole area of a disc sliced perpendicular to the growth axis, showing excellent compositional uniformity. The axial compositional variation was less than 2% over a length of 5mm. The FWHM values of X-ray rocking curves for 004 diffraction were in the range between 31 and 47 arcsec, showing excellent crystallinity. Such small FWHM values prove the elimination of the mosaic structure, which is a major issue in SiGe buffer layers on Si substrates. (C) 2015 The Japan Society of Applied Physics