| 摘要 |
PURPOSE:To obtain a single crystal having a high uniformity with little defects by easy operation, by inserting a cap of inverted funnel shape in the inner surface of a crucible, sealing the engaged part with a B2O3 melt, and controlling the temperature of the upper pipe and part of the cap. CONSTITUTION:The temperature of the upper and part of a pipe 3 of a cap 12 indicated by a thermocouple 17 is preset at such a temperature as to make an easily evaporable simple element, e.g. As, in a melt 3 e.g. GaAs, have a vapor pressure in equilibrium with the vapor pressure thereof, and the pressure of an inert gas in the outside is made equal to the pressure. The pulling up shaft 4, together with the cap 12, is lifted and lowered to seed the melt and pull up a single crystal while keeping this state. Thus, the pressure of As in the cap 12 keeps the given pressure, and evaporation loss of the As in the GaAs melt 3 is prevented to keep the composition of the melt constant during the pulling up. The pressure of the atmospheric gas is reduced, and the convection due to the heat is reduced to give the aimed single crystal having high uniformity and low dislocation density. |
