Effects of thermal annealing on the refractive index of amorphous silicon produced by ion implantation

Precise infrared reflection measurements of the refractive index of silicon show that there are two well-defined optical states of amorphous silicon produced by ion implantation. One is the as-implanted amorphous state which is the high refractive index state produced by high fluence implantation of Si or P ions into Si samples. The other state, which has a refractive index intermediate between the as-implanted and crystalline values, is induced by thermal annealing and is thermally stable until epitaxial recrystallization occurs.