Semiconductor Crystal Growth by Modified Vertical Gradient Freezing with Electromagnetic Stirring

This paper presents a numerical model for the unsteady transport of a dopant during the VGF process by submerged heater growth with a steady axial magnetic field and a steady radial electric current. Electromagnetic (EM) stirring can be induced in the gallium-antimonide melt just above the crystal growth interface by applying a small radial electric current in the melt together with an axial magnetic field. The application of EM stirring provides a significant convective dopant transport in the melt so that the crystal solidifies with relatively good radial and axial homogeneity. Dopant distributions in the crystal and in the melt at several different stages during growth are presented.