| 摘要 |
PURPOSE:To prepare a single crystal having long size and fixed concentration of impurity by supplying additional feed material to a space between a partition wall provided in a crucible and an inside wall of the crucible and pulling a single crystal from the melt of the feed contg. the impurity in the course of feeding of the additional material. CONSTITUTION:An escaping partition wall 11 made of Si3N4, etc. is floated preventing diffusion or mixing of melt or fixed keeping the center from causing no shift while providing holes on the partition wall 11 simultaneously, for additional feed material (undoped polycrystalline particles or undoped single crystal particles) in the inside of a quartz crucible 6 in a susceptor 5 provided with a feed heater 4 to the outside periphery, contained in a high pressure vessel 1. Melt of the feed 7 and a sealing material 10 are charged to the crucible 6, and a pulling single crystal 8 is pulled at a certain weight ds/dt weight of pulled single crystal per unit time) using an upper shaft 2 for pulling crystal, and a seed crystal 9. On one hand, an additional feed 15 having 0.5-5mm particle size in a sink 13 for the additional feed is supplied as feed material 16 to the melt 7 with (1-k)ds/dt feed rate (k is a segregation coefft.) through a feed pipe 12, and a feed shutter 14, and a weight sensor 20, etc.
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