Increased Lateral Crystallization Width during Nickel Induced Lateral Crystallization of Amorphous Silicon Using Fluorine Implantation

Abstract

This paper reports a study of the effect of fluorine implantation on the nickel-induced lateral crystallization of amorphous silicon. To distinguish the effects of the fluorine and the implantation damage, the fluorine implant is either made directly into the or into the buffer oxide below the . For a anneal at 500°C, both types of fluorine implant give a 65% increase in the lateral crystallization width, a five times reduction in the density of nickel silicide precipitates, and an improved grain texture. In contrast, for anneals at 550 and 600°C, both types of fluorine implant give 29% and 85% reductions in the lateral crystallization width, respectively. The identical results obtained for fluorine implantation into the and the buffer oxide indicates that the effects observed are due to chemical effects of the fluorine rather than implantation damage in the . The increased crystallization width at 500°C is explained by the suppression of random crystallization at the bottom interface. The reduced crystallization widths at 550 and 600°C are attributed to the diffusion and activation of fluorine and the formation of bonds making the more resistant to silicide-mediated phase transformation.