PRODUCTION OF SINGLE CRYSTAL

PURPOSE:To precisely control the amt. of Sb to be vaporized when a single crystal is pulled up and to uniformize the Sb concn. in the axial direction of the single crystal by adjusting the flow velocity of an inert gas to be blown against the melt surface and the melt area on which the inert gas is directly blown. CONSTITUTION:In the production of an Sb doped single crystal by the CZ method, a shielding member 9 is set above a crucible 2, and a control ring 10 is suspended below the member 9. When a single crystal 7 is grown, an inert gas such as Ar is supplied from the upper part to the region A surrounded with the control ring 10 on the melt surface in the crucible 2 at a specified flow velocity. The inert gas is mostly circulated along the melt surface in the region surrounded with the control ring 10, hence the amt. of the gas current is increased, the partial pressure of Sb is lowered, and the vaporization of Sb is accelerated. The area of the region A on which the inert gas is directly blown at a high flow velocity is changed by changing the diameter of the control ring 10, and the amt. of Sb to be vaporized is precisely controlled in combination with the flow velocity of the inert gas.