Zone refining and enhancement of solid phase epitaxial growth rates in Au-implanted amorphous Si.

Gold has been implanted into 2500angstrom layers of amorphous Si on Si substrates. Heating causes the Au to diffuse uniformly throughout the amorphous layer but not into the underlying crystalline Si. Epitaxial growth of the film is accompanied by segregation of the Au at the crystal-amorphous interface. When the Au concentration reaches .5 at .% an order of magnitude increase in the growth rate is observed. At Au concentration >0.7 at .% the interface motion is retarded. Concentration dependent changes in epitaxial growth rates are measured over the temperature range from 515C to 735C.