INCORPORATION OF HIGH-CONCENTRATIONS OF ERBIUM IN CRYSTAL SILICON

High concentrations (almost-equal-to 10(20)/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 X 10(20)/cm3 at 600-degrees-C to 6 +/- 2 x 10(19)/cm3 at 900-degrees-C.