Optical Investigations of Solid-Phase Crystallization of Si1-xGex

Solid-phase crystallization (SPC) of amorphous Si1-xGex(0≦x≦0.3) formed by ion-implantation into epitaxially-grown single crystals was investigated by using ellipsometric spectroscopy. We found that the attenuation constant of optical transition is proportional to the calculated defect density. Annealing-temperature profiles of the defect density during SPC of Si1-xGexwere obtained. It was found that the higher the defect density in the amorphous state, the lower the crystallization temperature of Si1-xGex. And increasing Ge concentration in Si, the crystallization temperature decreases monotonically, which implies a decrease in the activation energy of SPC. It is concluded that the increased lattice constant and reduced strain (caused by Ge introduction into Si) mainly control the SPC of Si1-xGex.