Nickel vs. cobalt silicide integration for sub-50nm CMOS

In this work, NiSi SALICIDE has been fully integrated with sub-50 nm gate length transistors and compared to its CoSi/sub 2/ counterpart. Nickel thickness has been reduced to target the CoSi/sub 2/ sheet resistance. It was found that NiSi layers basic lattice planes with vertical orientation are often observed inside the grains. NiSi-based CMOS transistors show the same performance as CoSi2-transistors, but nickel can also silicide very narrow poly lines whereas cobalt can not. Moreover, NiSi reduces the STI diode-leakage perimeter, but increases channel side leakage, where CoSi/sub 2/ shows a "Schottky behavior". Thus we show that nickel allow MOS transistor scaling for future technology.