Effects of implantation impurities and substrate crystallinity on the formation of NiSi2 on silicon at 200–280 °C

Abstract

The influences of implantation impurities, such as BF2, B, F, As and P, as well as silicon substrate crystallinity on the formation of NiSi2 at 200–280 °C in nickel thin films on ion-implanted silicon, have been investigated by transmission electron microscopy. In implantation-amorphous samples no NiSi2 formation was detected at 200–280 °C. The presence of BF2, B, and F atoms was found to promote the epitaxial growth of NiSi2 in nickel thin films on crystalline silicon at low temperatures. Little or no effect on the formation of NiSi2 was found for As+- and P+-implanted samples. The results indicated that the influences of the implantation impurities are not likely to be chemical in origin. The presence of electrically active impurities in crystalline silicon alone was not sufficient to induce the formation of epitaxial NiSi2 at low temperatures. On the other hand, good correlation was found between the atomic size factor and resulting stress and NiSi2 epitaxy at low temperatures.