| 摘要 |
PURPOSE:To decrease the twist in the outside shape of a crystal, by rotating the crystal at a low speed to project the solid-liquid boundary toward the melt and to maintain the shape of the crystal section at a circular shape in the initial period of crystal growth, and increasing gradually the rotating speed of the crystal to flatten the solid-liquid boundary upon stabilization of the growth then moving the crucible gradually upward to the position higher than a high-frequency coil. CONSTITUTION:The formation of the shoulder part of a Bi4(Ge, Si)3O12 single crystal is acomplished by rotating the crystal at such low speed as to project the solid-liquid boundary of the crystal toward the melt and to maintain the circular section in the outside shape of the crystal, in the growth of said single crystal by a Czochralski method using high frequency indiction heating. The upper part in the parallel part of the crystal part is formed under the same condition, whereafter the rotating speed of the crystal is increased so as to flatten the solid-liquid boundary of the crystal and the crucible is moved upward to the position higher than the high brequency coil at the speed 80-100% of the speed at which the melt level decreases with crystallization, whereby the principal part of the signle crystal is formed. |
