Accelerated VGF-crystal growth of GaAs under traveling magnetic fields

Accelerated VGF-growth of 4 in. GaAs ingots by downwards traveling magnetic fields (TMFs) was investigated numerically. The focus was led on the feasibility of control of s/l interface shape by Lorentz forces in the range of crystal growth rates from 3 to 9 mm/h. Particularly, the aim of this study was to derive a method for a prediction of electro-magnetic parameters of TMF such as frequency, phase shift and AC amplitude that provide maximal improvement of interface deflection towards convex morphology during the fast growth.A typical VGF furnace equipped with a KRISTMAG® internal heater-magnet module was used for the simultaneous generation of heat and TMF.The revealed deflections were correlated with dimensionless numbers: Grashof Gr, Stephan Ste and Forcing number F. With an increase of F while holding Gr and Ste numbers constant, transition through the point of maximal positive deflection was marked by a lift of the stream function vortex from the region of triple point upwards.

► Accelerated VGF-growth of 4 in. GaAs ingots by TMF was investigated numerically.
► Focus was led on the feasibility of control of interface shape by Lorentz forces.
► Method was derived for a prediction of electro-magnetic parameters of TMF.
► Study comprised the crystal growth rates in the range from 3 to 9 mm/h.