SELF-ALIGNED NICKEL-MONO-SILICIDE TECHNOLOGY FOR HIGH-SPEED DEEP-SUBMICROMETER LOGIC CMOS ULSI

A nickel-monosilicide (NiSi) technology suitable for a deep sub-micron CMOS process has been developed. It has been confirmed that a nickel film sputtered onto n(+)- and p(+)-single-silicon and polysilicon substrates is uniformly converted into the mono-silicide (NiSi), without agglomeration, by low-temperature (400-600 degrees C) rapid thermal annealing. This method ensures that the silicided layers have low resistivity. Redistribution of dopant atoms at the NiSi-Si interface is minimal, and a high dopant concentration is achieved at the silicide-silicon interface, thus contributing to low contact resistance. This NiSi technology was used in the experimental fabrication of deep-sub-micrometer CMOS structures; the current drivability of both n- and p- MOSFET's was higher than with the conventional titanium salicide process, and a ring oscillator constructed with the new MOSFET's also operated at higher speed.