Liquid-solid coexisting annealing of a-GeSn/Si(100) structure for low temperature epitaxial growth of SiGe

To develop a new low-temperature crystallization technique, annealing characteristics of a-GeSn/Si(100) structures are investigated. It is revealed that epitaxial growth accompanying Si-Ge mixing is generated at temperatures in the liquid-solid coexisting region of the Ge-Sn system. The annealing temperature necessary for epitaxial growth is significantly decreased by increasing annealing time and/or Sn concentration. Consequently, epitaxial growth at 300°C becomes possible. These findings are expected to be useful to realize next-generation large-scale integrated circuits, where various multi-functional devices are integrated.