| 摘要 |
PURPOSE:To prevent the contamination of a crystal with carbon in the production of a single crystal by Czochralski process, by separating an atmospheric gas contacting with B2O3 used as a sealant from an atmospheric gas contacting with a graphite material such as heater. CONSTITUTION:A lower inner tube 5 made of quartz and holding a crucible 15 is provided, a hole larger than the outer diameter of a seed crystal holder 6 is opened at the center of an upper inner tube 1 and the gap between the inner tube 1 and the holder 6 is sealed with a sealing B2O3 to prevent the passage of atmospheric gas between the outside and the inside of the inner tube. The inner tubes 1 and 5 are maintained in hermetic state by a fitting structure and the apparatus is provided with an inert gas introducing port 2 and a valve 4 to release the pressure in the inner tube to the outside of the tube. A raw material and a sealing B2O3 are put into the crucible 15, the inner tube 5 is inserted into a susceptor 14, the crucible is positioned, the inner tube 1 is fit to the inner tube 15, an introducing pipe 2 is connected and B2O3 3 is placed at the top of the inner tube 1. Crystal growth of a compound semiconductor is performed in the above state. Since the atmospheric gas contacting with B2O3 is kept from contact with a graphite part such as heater 13 and a heat-insulation material 12, the intrusion of carbon into grown crystal can be prevented.
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