| 摘要 |
PURPOSE:To obtain a single crystal with low dislocation density as a whole when a single crystal is pulled up by the Czochralski method, by growing a single crystal so that the diameter is gradually reduced from the front part toward the back part. CONSTITUTION:When a single crystal is pulled up by the Czochralski method, the diameter D0 of the front part of a single crystal is fixed to a certain size, and in accordance with the growth of the crystal, the diameter is gradually reduced to a diameter D1 at the back part which is away from the front part by a distance Z1. By this method the angle of the surface of the crystal to the surface of a melt is reduced, and the crystal receives radiation from the melt and makes the temp. gradient smaller in the vicinity of the interface where the crystal is grown. Accordingly, a single crystal with low dislocation density can be pulled up. |
