SHAPE CONTROL IN CRYSTAL PULLING FROM A FLOATING DIE

Controlling the final crystal shape is a major objective in the die-pu lled crystal growth processes. The as-grown crystal shape is affected by many factors. Among these, thermal-capillary interaction is the key factor that controls the final crystal shape and dimension. In this p aper, the shape control of a crystal pulled from a floating die is stu died through experiments and three-dimensional thermal-capillary simul ation. Crystal pulling of tin from a weighted floating die is used as a model system. The effects of key process parameters, including the a pplied weight and the temperature and the shape of the die, on the fin al crystal shape are discussed.