Enhanced VGF-GaAs growth using pulsed unidirectional TMF

Abstract A novel electro-magnetic stirring approach using pulsed downward traveling magnetic fields (TMF) generated by side KRIST MAG ® heater magnet module (HMM) is proposed for 4 in. VGF-GaAs single crystal growth. 3D numerical study was performed to identify key pulsing parameters and assess the potential of pulsing modus operandi for enhancement of temperature and Lorentz force density homogeneity in GaAs melt if perturbations originated from rotational asymmetric HMM design. Results showed superiority of pulsed to conventional TMF if sinusoidal AC magnitude modulation technique with pulse frequency f p =0.3 Hz and pulse amplitude 50 % of unmodulated AC value was applied. The proposed technique enabled quick and straightforward process improvement avoiding expensive hardware changes.