Advances in selective etching for nano scale salicide fabrication

High temperature SPM based wet selective processing for multi-step NiPt silicide process on nanoscale CMOS structure with dual gate dense layout has been studied. The high temperature SPM process is found to have better etching selectivity between NiPt/TiN and nickel rich silicide (Ni₂Si/Ni₃Si₂) and results in better sheet resistance (Rs) and uniformity compare to HCL based process. The high temperature SPM process window is effective for Pt and induces very low material loss. Thus, it is a better selective etching process for multi-step silicide process that can scale with the CMOS technology toward 22 nm node.