Growth of a Si0.50Ge0.50 crystal by the traveling liquidus-zone (TLZ) method in microgravity

Publication date: 15 February 2014
Source:Journal of Crystal Growth, Volume 388
Author(s): K. Kinoshita , Y. Arai , Y. Inatomi , T. Tsukada , S. Adachi , H. Miyata , R. Tanaka , J. Yoshikawa , T. Kihara , H. Tomioka , H. Shibayama , Y. Kubota , Y. Warashina , Y. Sasaki , Y. Ishizuka , Y. Harada , S. Wada , C. Harada , T. Ito , M. Takayanagi , S. Yoda
An alloy semiconductor Si1−x Ge x (x~0.5) crystal was grown by the TLZ method in microgravity. Ge concentration was 48.5±1.5at% for the whole region of 10mm diameter and 17.2mm long crystal. Compositional uniformity was established but the average concentration was a little deviated from the expected 50at%. For further improving compositional uniformity and for obtaining Si0.5Ge0.5 crystals in microgravity, growth conditions were refined based on the measured axial compositional profile. In determining new growth conditions, difference in temperature gradient in a melt, difference in freezing interface curvature, and difference in melt back length of a seed between microgravity and terrestrial growth were taken into consideration.