Optical investigations of solid-phase crystallization of Si1-xGex

Solid-phase crystallization (SPC) of amorphous Si1-xGex (0 less than or equ al to x less than or equal to 0.3) formed by ion-implantation into epitaxia lly-grown single crystals was investigated by using ellipsometric spectrosc opy. We found that the attenuation constant of optical transition is propor tional to the calculated defect density. Annealing-temperature profiles of the defect density juring SDC of Si1-xGex were obtained. It was found that the higher the defect density in the amorphous state, the lower the crystal lization temperature of Si1-xGex. And increasing Ge concentration in Si, th e crystallization temperature decreases monotonically, which implies a decr ease in the activation energy of SPC. It is concluded that the increased la ttice constant and reduced strain (caused by Ge introduction into Si) mainl y control the SPC of Si1-xGex.