Developing a model for electromagnetic control of dopant segregation during liquid-encapsulated crystal growth of compound semiconductors

摘要

The dopant transport during growth depends on both the diffusion and the convection of dopant during the entire period of time needed to grow a crystal. The application of even a moderate magnetic field is enough to damp the melt motion in order to eliminate oscillatory or turbulent melt motions which cause microsegregation or striations, and provide the electromagnetic control needed to minimize macrosegregation. For the moderate-strength magnetic fields used during liquid-encapsulated crystal growth processes, the dopant transport in the melt is dominated by convection, and the constant-concentration curves resemble the streamlines. The strong flow adjacent to the crystal-melt interface produces a lateral uniformity in the dopant concentration in the melt adjacent to the interface and consequently in the crystal.