IRRADIATION OF SILICON WITH A PULSED PLASMA BEAM CONTAINING MO IONS

This paper presents preliminary results of a new approach to forming a refractory metal (Mo) layer on Si, using intense pulses of Mo-N plasm a. The new approach overcomes an inherent difficulty of mixing two mat erials with dissimilar surface tensions in the liquid state when using proton beam pulses for melting the predeposited surface layer of a re fractory metal. Previous attempts to mix a refractory metal with Si us ing the latter pulses were unsuccessful owing to a tendency of the pul se-melted refractory metal layer to collect into droplets and splash o ff. Since in the new approach the plasma-borne Mo atoms ''sink'' in th e molten Si layer, there is no opportunity for them to form a separate Mo layer and an effective mixing between Mo and Si takes place. This mixing is demonstrated by the Mo in Si profiles obtained by Auger elec tron spectroscopy. (C) 1997 Elsevier Science S.A.