Direct patterning of nanometer-scale silicide structures on silicon by ion-beam implantation through a thin barrier layer

CoSi2 structures were formed by focused ion-beam implantation. Patterned si licide lines with dimensions down to 150 nm were produced on (100) silicon. The process involved the ion implantation of 200 keV As++ through a cobalt (34 nm)/oxide (similar to2 nm) thin film structure. The thin oxide at the Si/Co interface acted as a selective reaction barrier. Ion-beam mixing disr upted the oxide layer to allow silicidation to proceed during subsequent ra pid thermal anneal treatments. Reactions were inhibited in nonimplanted are as. A threshold dose of 3x10(15) cm(-2) was required for process initiation . Electrical measurements resulted in resistivities ranging from 15 to 30 m u Omega cm. (C) 2001 American Institute of Physics.