Process Design for the Shape Controlling of Pulled Growth Crystal

A model relating the diameter variation with the process parameters during a practical crystal growth by pulling has been proposed. The crystal shape evolution under various growth process was analysed. The results prove, in theory, that the most effective and convenient measure to control the crystal diameter is adjusting the pulling rate, and the optimal process for growing a equal diameter crystal is simultaneously decreasing the pulling rate and the heater temperature with dropped decreasing rate. Moreover, the model could be used for designing the process for growing a crystal with a desired shape. Keyword:crystal growth, shape design, process design, numerical method