Segregation and Trapping of Gold During Ion-Induced Crystallization of Amorphous Si.
01 January 1987
A novel regime of crystal growth and segregation has been observed. Amorphous Si layers were uniformly doped with Au and epitaxial crystallization was induced in the temperature range 250-420C using 2.5 MeV Ar ion irradiation. The Au segregation at the amorphous/crystal interface is analogous to behavior at liquid/solid interfaces except that the interfacial segregation coefficient of 0.007 at 320C is independent of velocity between 0.6 and 6angstroms/sec. This process results in the trapping of Au in crystalline Si at concentrations some ten orders of magnitude in excess of equilibrium concentration.