| dc.description.abstract | As the complementary metal-oxide-semiconductor (MOS) transistor device size shrinked, self-aligned silicidation process have been faced with the limitation on the process. Recently, in order to increase MOSFET device performance, conventional metal silicide source/drain was replaced by epitaxial metal silicide source/drain structures, formed quite flat epitaxial silicide and effectively reduced the contact resistance in the silicide/silicon junction. It reported that the thickness of nickel is less than a critical thickness, epitaxial nickel disilicide can be generated at low temperatures without passing through other intermediate phase. According to the above phenomenon, the study was investigated through the different nickel alloy epitaxial silicide formation mechanism and the effect of different doping elements, which was prepared by magnetron sputter deposition system including the Ni1-xPtx/Si, Ni1-yTiy/Si and Ni1-zAlz/Si systems. It was found that after depositing and then metal etching a nickel-silicon would be leaved as a mixed layer. Subsequent annealing at low temperature of a mixed layer resulted in an ultrathin epitaxial nickel disilicide, which suppressed a lot of inverted pyramid structures and the leakage currents. The electrical properties, lattice symmetry, surface morphology, bonding analysis, alloying elements distribution and atomic-scale microstructure were then analyzed by four point probe, electron back-scattered diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy, transmission electron microscopy, respectively. An ultrathin nickel alloy epitaxial silicide is the promising material for the application in advanced metal-oxide MOSFET source/drain contact.
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