A novel high aspect ratio FinFET with cobalt fully silicided gate structure

High aspect ratio 35nm FinFET devices with nitrided oxide gate dielectrics have been successfully integrated with a fully silicidated (FUSI) CoSi₂ gate electrode. To prevent the possible CoSi₂-FUSl gate line discontinuity below 65nm gate lengths, for the 1st time FinFET devices used a time-mode oxide CMP to remove the upper protruded ILD SiO₂ and SiN_x liner layer as well as part of the top poly-Si gate for opening a "poly-Si reaction window" for the subsequent contacted reaction of the CoSi₂-FUSI gate structure. The CoSi₂-FUSI gate electrode also demonstrates its capability to drastically reduce the device off currents (Ioff) through threshold voltage (Vt) adjustment and higher thermal budget than that of NiSi-FUSI gate.