Amplitudes of doping striations: Comparison of numerical calculations and analytical approaches

Transient, axisymmetric numerical calculations of the heat and species transport including convection were performed for a simplified vertical gradient freeze (Bridgman) process with bottom seeding for GaAs. Periodical oscillations were superimposed onto the transient heater temperature profile. The amplitudes of the resulting oscillations of the growth rate and the dopant concentration (striations) in the growing crystals are compared with the predictions of analytical models.