TITANIUM SILICIDE/P-SI SCHOTTKY BARRIERS FORMED BY RAPID THERMAL-PROCESSING IN NITROGEN

Schottky barriers have been made by evaporation of Ti on p-Si and subsequent rapid thermal processing in N2 (temperature range from 100 to 1200-degrees-C). Our former results concerning the silicidation of the native SiO(x) layer and TiSi2 formation could be confirmed and moreover have been followed as a function of time. Rapid thermal processing leads to smaller interface widths at the silicide/Si boundary, improving the ideality factor of the Schottky diodes. The short anneal times limit the uptake of oxygen in Ti, lowering the resistivity of the layer. Auger depth profiling reveals inward nitridation from the surface and outward silicidation from the silicide/Si interface at 600-degrees-C. The snowploughed O2 penetrates the nitride and the nitridation front ceases at 700-degrees-C due to the silicidation. At 1200-degrees-C, the oxygen has disappeared and some conversion of TiSi2 into TiN occurs.