A novel NiSi selective wet etch on Si and on SiGe

As the critical dimension goes down to sub micron range, salicide (self-aligned-silicide) technology has become a crucial step in the fabrication process of ultra-high-speed CMOS devices. Among salicides processes, nickel salicide is recently becoming an appealing candidate to replace the traditionally used TiSi_x and CoSi_x in aggressively scaled structures. A novel NiSi selective wet etch is presented in this research, and the results are compared with the traditionally used SPM (sulphuric peroxide mixture) process. The ability of both chemistries to remove un-reacted metal on Si, SiN and SiGe substrates is compared. Electrical measurements, as well as physical behaviors are discussed.