Formation of Nickel Self-Aligned Silicide by Using Cyclic Deposition Method

We have developed a novel nickel self-aligned silicide (salicide) process for future scaled metal-oxide-semiconductor field-effect transistors (MOS-FETs). Ni/Si multi-layered structures were fabricated by the cyclic deposition of Ni and Si. Nickel monosilicide (NiSi) films with a low resistivity, a uniform thickness, and a good morphology were obtained on Si(100) substrates after annealing at 400–600°C. Nickel silicide formed on SiO2 can be removed by wet etching if the total atomic number ratio of Ni to Si in the deposited layers is larger than unity. This shows that the nickel salicide process is possible by our method. We have fabricated MOS-FET structures with NiSi and confirmed that the consumption of Si in the substrate is much lower in our method than in the conventional method.