Semiconductor single-crystal pulling apparatus

摘要

In the manufacture of a single crystal using a semiconductor single-crystal pulling apparatus equipped with a radiation screen, the time of passage of the single crystal through the high-temperature region of 1050 DEG C. and above is made to be long and the time of passage of the single crystal through the temperature region of about 900 DEG C.-500 DEG C. is made to be short. The semiconductor single-crystal pulling apparatus is so constructed that a radiation screen comprises an upper screen of 3-layer construction consisting of a heat-insulating member made of graphite or ceramics fiber clad with outer members made of graphite and a lower screen 3 of single-layer construction made of graphite, quartz or fine ceramics. Radiant heat from the molten liquid heats the lower part of single crystal as it passes through lower screen, thereby prolonging its period of passage through the high-temperature region. The radiant heat cannot reach single crystal when it is surrounded by upper screen, so it is cooled comparatively abruptly and can pass through the temperature region of about 900-500 DEG C. in a short time.