Automatic control of crystal pulling device comprises initially lowering seed crystal into melt in crucible, and pulling from melt at speed of crystal growth to form crystal block

摘要

The automatic control of a crystal pulling device comprises initially lowering a seed crystal (7) into a melt (3) in a crucible; and pulling from the melt at the speed of crystal growth to form a crystal block. An optical sensor (13) is used during lowering of the seed crystal to obtain a sensor signal at a point at which the seed crystal lies above the melt. An Independent claim is also included for a crystal pulling device. Preferred Features: A CCD camera is used as the optical sensor