TITANIUM SILICIDE AND TITANIUM NITRIDE FORMATION BY TITANIUM-ION IMPLANTATION FOR MOS LSI APPLICATIONS

A 70-nm-thick, 19-mu-OMEGA . cm TiSi2 layer is formed using a Ti-ion implantation technique. TiN/TiSi2 double layers, whose surface morphology is superior to that obtained with conventional deposition and reaction techniques, can also be simultaneously formed by Ti-ion implantation into monocrystalline Si screened with the Si3N4 film. Discrete pn-junction diodes with a shallow TiSi2 layer and Ti-polycide-gate MOS capactiors are fabricated to determine the influences of Ti-ion implantation on electrical characteristics. The leakage current of the B-doped p+n junction and As/P-doped n+p junction with Ti-ion implanted silicide layer is low enough for device applications. Silicide formation on the gate polycrystalline-Si does not affect the breakdown electric field strength of a 20-nm-thick gate oxide. MOS capacitors showed normal C-V characteristics.