Effective work function modulation (Φm,eff) and the thermal/electrical stability of NiSi fully-silicided (FUSI) gates on SiO 2 and HfO2 are investigated. A new method, implant-to-silicide, differing from the pre-doped method, is used to realize Φm,eff adjustments. The Φm,eff of NiSi FUSI gates on SiO2 can be tuned by incorporating BF2+ or P + dopants after silicidation. Nevertheless, the Fermi-pinning effect was observed in the NiSi/HfO2 gate which limits the Φm,eff adjustment. A thin SiO2 interfacial layer can reduce the Fermi-pinning effect. A NiSi FUSI gate on SiO2 is thermally stable up to 600°C. The thermal stress and impurity diffusion after a prolonged 600°C annealing degraded the oxide integration. The temperature of the post-silicidation process should be as low as possible to lessen the thermal stress and impurity diffusion.
|Number of pages||6|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|State||Published - 7 Jul 2006|
- FUSI gate
- Metal gate