Metallization of ion beam synthesized Si/3C-SiC/Si layer systems by high-dose implantation of transition metal ions

The formation of metal silicide layers contacting an ion beam synthesized b uried 3C-SiC layer in silicon by means of high-dose titanium and molybdenum implantations is reported. Two different strategies to form such contact l ayers are explored. The titanium implantation aims to convert the Si top la yer of an epitaxial Si/SiC/Si layer sequence into TiSi2, while Mo implantat ions were performed directly into the SiC layer after selectively etching o ff all capping layers. Textured and high-temperature stable C54-TiSi2 layer s with small additions of more metal-rich silicides are obtained in the cas e of the Ti implantations. Mo implantations result in the formation of the high-temperature phase beta -MoSi2, which also grows textured on the substr ate. The formation of cavities in the silicon substrate at the loa er SiC/S i interface due to the Si consumption by the growing silicide phase is obse rved in both cases. It probably constitutes a problem, occurring whenever t hin SiC films on silicon have to be contacted by silicide forming metals in dependent of the deposition technique used. It is shown that this problem c an be solved with ion beam synthesized contact layers by proper adjustment of the metal ion dose. (C) 2001 Elsevier Science B.V. All rights reserved.