Formation of metastable supersaturated solid solutions in ion implanted silicon during solid phase crystallization

We have investigated maximum solubility limits and extended defects in Si-Sb, Si-In, Si-Ga, Si-Bi, and Si-As systems after ion implantation and solid phase epitaxial growth in the temperature range 450-600 °C. The maximum concentration of solutes in ’’defect-free’’ layers were found to exceed the respective retrograde solubility limits by as much as a factor of 560 in Si-Bi system. The maximum concentrations depended upon the substrate temperature and the ion current during implantations, which presumably affected the degree of amorphousness or free energy of as- implanted silicon.