Si liquid-amorphous transition and impurity segregation

Abstract
Pulsed laser irradiation of amorphous Si has been used to produce undercooled liquid Si from which the amorphous phase can directly form. Implanted In, Bi, and As impurities are observed to diffuse and be segregated in a novel fashion by liquid-amorphous interfaces moving from the bulk and surface. Ultrathin impurity segregation layers can be formed within amorphous Si by this process. The first measurements of interfacial segregation coefficients during a liquid-amorphous transition are found to be similar to liquid-crystal values at the same velocity.