| 摘要 |
PURPOSE:To automatically control diameter of neck part of single crystal in high accuracy by bringing seed crystal into contact with melt, pulling up the seed crystal at definite speed for set time to grow single crystal, measuring diameter of the lower end of the single crystal after the lapse of a set time and correcting electric power to be supplied to a heater for heating melt from the measured value. CONSTITUTION:Polycrystal silicon is put in a crucible 16 and heated by a heater 18 to form melt 22. Then, the lower end of seed crystal 30 attached to the lower end of wire 26 is brought into contact with the melt 22 and pulled up at definite speed for a set time to grow silicon single crystal 32. Then, after the lapse of a set time, diameter of the silicon single crystal 32 at the lower end is measured by a camera 38, a diameter instrument 40, etc. Then electric power to be supplied to a heater 18 to heat the melt 22 is controlled by a microcomputer 58 depending upon deviation from an expected value of the measured diameter and corrected to automatically control diameter of neck part of the single crystal 32. |
