ION-BEAM-INDUCED COSI2 LAYERS - FORMATION AND CONTACT PROPERTIES

In this study, the influence of Ge and As ion energy, respectively, on the mixing behavior and the contact properties of the Co-Si system wa s investigated by Monte Carlo simulations, SIMS, RBS, TEM, and electri cal measurements. To achieve silicided n(+)p junctions, 30 nm Co on Si was mixed with (1-5)X10(15) cm(-2) Ge or As ions in the energy range from 50 to 200 keV. Silicidation was performed in a RTA system at 700 and 1000 degrees C. In the case of Ge mixing, the n(+)p junction was f ormed by As implantation either before or after silicidation. It could be shown that ion-beam mixing with Ge and As ions followed by rapid t hermal annealing lead to homogeneous silicidation for all mixing energ ies and ion species used. SIMS analysis of doping profiles as well as measurement of leakage currents revealed, however, that only Ge ion-be am mixing is an appropriate method for formation of low-resistivity, h omogeneous silicide contacts either on previously or subsequently form ed shallow n(+)p junctions.