Tunable work function molybdenum gate technology for FDSOI-CMOS

A simple technique for tuning the work function of molybdenum (Mo) gate material over a wide range (4.5 V-4.9 V) is investigated. Ultra-low energy (/spl les/3 keV) Ar/sup +/ and N/sup +/ ion implantation is used to selectively induce structural and/or chemical changes in Mo gate films. These changes are shown to directly affect the Mo gate work function, so that it can be adjusted by adjusting the implant parameters and annealing conditions. The mechanism behind this phenomenon is investigated using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The applicability of this technique for threshold voltage (V/sub TH/) control, particularly in fully-depleted SOI CMOS devices, is demonstrated with Mo gated ultra-thin body (UTB) SOI MOSFETs and double-gate FinFETs.