OUTER DIAMETER DETECTION FOR SINGLE CRYSTAL MADE BY THE LEC METHOD WITH X-RAYS

摘要

PURPOSE:The value which is obtained by measuring the distance between the side face of the single crystal and the side wall of the crucible opposing to the crystal by roentgenographic pictures is subtracted from the radius of the crucible to detect the outer diameter of the single crystal even with a beam width of X-rays narrower than the outer diameter of the single crystal. CONSTITUTION:A seed crystal 4 is brought into contact with the melt of starting materials for single crystal and the liquid selant 2 and pulled up to allow a single crystal 5 to grow at the center of the crucible. An X-rays generator 7a and an X-ray detector 9a are set oppositely in front and in rear of the crystal 5 so that the X-rays 9a from the generator 7a may pass through the center of the crucible 3 and the side wall opposing to it. Thus, the distance between the side of the single crystal 5 and the opposing side wall of the crucible is measured with a roentogenographic picture of the single crystal 5. The value is subtracted from the radius of the crucible to detect the outer diameter of the single crystal 5.