Electromagnetic Phenomena in Crystal Growth

Abstract

Integrated circuits and optical devices are produced on wafers sliced from single crystals that are grown from a body of liquid semiconductor or melt. The crystal must have few defects, such as dislocations, and must have uniform distributions of dopants, which are added to the melt to give the crystal the desired electrical or optical properties. Since molten semiconductors have large electrical conductivities, magnetic fields can be used to eliminate hydrodynamic instabilities in the melt and to tailor the convective dopant transport. For silicon, controlling the convective transport of oxygen is important, and a particular nonuniform axisymmetric magnetic field is optimal for this purpose. For compound semiconductors, such as gallium-arsenide, eliminating instabilities in the buoyant convection is necessary for the growth of large crystals with few defects.