Interfacial reaction and electrical properties in Ni/Si and Ni/SiGe(C) contacts

We have investigated the interfacial solid-phase reaction and electrical properties of Ni/Si and Ni/SiGeC systems with various Ge and C compositions. The incorporation of Ge into Si substrates raised the transition temperature from the NiSi phase to the NiSi ₂ phase. The incorporation of C effectively suppresses the agglomeration of NiSi and the formation of {111} facets at NiSi ₂ /Si interface, which provides the low sheet resistance even after high temperature annealing. NiSi/Si systems show the contact resistivity as low as 10 ^-8 Ωcm ² for both n ⁺ - and p ⁺ -type contacts. This is accounted by the pile-up of P at the NiSi/Si interface for n ⁺ -type and the low Schottky barrier height for p ⁺ -type contact. The pile-up of B at the NiSi/p ⁺ -Si _0.996 C _0.004 interface after the annealing at 750°C is also found.