The impact of forming temperature on material and electrical characteristics of nickel silicide gate electrode

In this letter, the material and electrical characteristics of the nickel silicide (NiSi) formed at various RTA temperatures as gate electrode has been studied. By comparing various samples formed at 400 ??C 450 ??C 500 ??C and 600 ??C with Vfb-EOT curves, work function and fixed charge, we found that when the RTA temperature is higher than 500 ??C the interaction between the NiSi and SiO2 will damage the gate dielectric (silicon dioxide) and change the effective work function of the NiSi (from 400 ??C 4.47eV to 600??C 4.64eV) by defects which is result of Ni-Si bonds. And the work function of NiSi is 4.47 ?? 0. 02eV (formed at 400??C 450??C 500??C). Finally we compared the reliability of the NiSi gate capacitor formed at 400 ??C 450 ??C and 500 ??C, and get the conclusion that NiSi formed at 400 ??C 450 ??C is stable on the silicon oxide. ? 2006 IEEE.EI