Titanium Silicide on Si:P With Precontact Amorphization Implantation Treatment: Contact Resistivity Approaching 1 \times 10^-9 Ohm-cm2.

In recent CMOS technology, extreme shrinking of contact area at source/drain regions raises serious concerns of high metal/semiconductor contact resistance. Confronting this problem, we introduce a precontact amorphization implantation plus Ti silicidation technique (PCAI + TiSix) and achieve ultralow contact resistivity ( \rho c ) of (1.3 – 1.5) \times 10^-9 ~\Omega \cdot \text cm^2 on Si:P. This PCAI + TiSix technique utilizes light amorphization (low-energy implantation), thin Ti and TiSix film, and moderate thermal budget (500 °C –550 °C): these features are compatible with modern CMOS manufacturing. Moreover, the PCAI + TiSix-induced \rho c reduction is proved universal on both n- and p-Si. With additional characterizations, we find that the silicidation-induced \rho c variation is not merely a Schottky barrier height tuning effect. The electrical and physical characterizations suggest that the low \rho c is strongly correlated with the formation of interfacial TiSix crystallites between amorphous TiSi alloy and Si. [ABSTRACT FROM PUBLISHER]