FORMATION AND CONTACT PROPERTIES OF TITANIUM-SILICIDED SHALLOW JUNCTIONS

In this study, TiSi2 contacts were fabricated using self-aligned silicidation technology by ion-beam mixing with germanium. The implantation energy for the mixing process was optimized by comparing Monte-Carlo simulations with sputtering neutral mass spectroscopy (SNMS) results. Shallow p+n junctions of 150 nm depth could be formed by 13 keV boron implantation in silicided germanium amorphized silicon substrates. For germanium amorphization, three implantation energies were chosen to cause an overlap between interstitial-rich areas of low energy implantation with vacancy-rich regions of subsequent high energy implantations. Using this triple germanium amorphization, end-of-range defect concentrations could be appreciable reduced compared to convential substrate amorphization, leading also to improved electrical characteristics. By triple germanium amorphization and 13 keV boron implantation low leakage currents of 10 nA and an ideality factor of 1.08 could be achieved.