Incorporation of high concentrations of erbium in crystal silicon

Abstract

High concentrations (≊1020/cm3) of Er have been incorporated in crystal Si by solid phase epitaxy of Er-implanted amorphous Si. This concentration is some 2 orders of magnitude higher than has previously been achieved. During thermal recrystallization of the amorphous layer, segregation and trapping of Er occurs at the moving crystal/amorphous interface. As long as the concentration of Er trapped in the crystal remains below a critical level, perfect epitaxial regrowth occurs. This concentration limit is temperature dependent, decreasing from 1.2±0.2×1020/cm3 at 600 °C to 6±2×1019/cm3 at 900 °C.