CZ growth of semiconductor crystals with high perfection (like silicon) requires a flat solid-liquid interface.

The growth system such as Vertical Bridgman (VB), Vertical Gradient Freeze (VGF) and Vertical directional solidification (VDS) are used for the bulk growth of material at the critical growth condition and parameters. For VDS technique you may refer our research reports into research gate. When interface is nearly flat or plane, the bulk crystal showed the high crystalline quality. This approach had been observed into space grown crystal by the detached crystals.