微小重力下での浮遊帯域溶融法(<特集>無重力下における結晶成長)

概要

論文の詳細を見る
A space experiment on floating-zone crystal growth was carried out in Spacelab-J mission aboard space shuttle Endeavour. Prior to the experiment, analysis on the stability of the floating zone was made. It was elucidated that melt zones of any size of diameter are stably sustained in microgravity by its surface tension without depending on its surface tension or its density in the floating zone method in microgravity. In the space experiment, the verification was made on large diameter crystal of semiconducting compound InSb that can not be processed in terrestrial condition by floating zone method, because of its low surface tension and of its high density. The crystal obtained by the space experiment was 20 mm in diameter and 100 mm in length, which is the largest one that has ever been grown in space and is the first compound semiconductor grown in space by floating zone method. The crystallographic quality was highly improved by the space processing. The etch pits density was reduced down to 8.2×10^6/m^2, and carrier density down to 4.2x10^<19>/m^3. The high quality is likely due to the thin oxide film formed on the floating liquid zone. The oxide film coating the liquid zone during all over the crystal growth process acted as a flexible container that prohibited the Marangoni convection flow in the melt without making stress and making chemical contaminations on the growing crystal.
日本結晶成長学会の論文
1994-09-25