Investigation of high-K gate stacks with epitaxial Gd(2)O(3) and FUSINiSi metal gates down to CET=0.86 nm

Novel gate stacks with epitaxial gadoliniurn oxide (Gd(2)O(3)) high-k dielectrics and fully silicided (FUSI) nickel silicide (NiSi) gate electrodes are investigated. Ultra-low leakage current densities down to 10(-7) A cm(-2) are observed at a capacitance equivalent oxide thickness of CET = 1.8 nm. The influence of a titanium nitride (TiN) capping layer during silicidation is studied. Furthermore, films with an ultra-thin CET of 0.86 nm at a Gd(2)O(3) thickness of 3.1 nm yield current densities down to 0.5 A cm(-2) at V(g) = + 1 V. The extracted dielectric constant for these gate stacks ranges from k = 13 to 14. These results emphasize the potential of NiSi/Gd(2)O(3) gate stacks for future material-based scaling of CMOS technology.
QC 20120229