Patent ID: 7291221

Claim:
A method of controlling crystal growth in a crystal growing apparatus, said crystal growing apparatus having a heated crucible containing a semiconductor melt from which a monocrystalline ingot is grown according to a Czochralski process, said ingot being grown on a seed crystal pulled from the melt, said method comprising: applying a magnetic field to the melt, said magnetic field affecting convection in the melt; sensing a growth parameter of the ingot being pulled from the melt; comparing the sensed growth parameter to a target growth parameter; determining a power adjustment parameter for achieving a desired effect on the growth parameter of the ingot, said desired effect being based on the comparing; and varying the magnetic field applied to the melt while the ingot is being pulled from the melt as a function of the determined power adjustment parameter, said varying of the magnetic field producing a pumping force in the melt, wherein said pumping force selectively increases and decreases a velocity of convective flow in the melt to achieve the desired effect on the growth parameter.