Demonstration of Ni fully germanosilicide as a pFET gate electrode candidate on HfSiON

We report for the first time on the use of a Ni fully germano-silicide (FUGESI) as a metal gate in pFETs. Using HfSiON dielectrics and comparing to Ni FUSI devices, we demonstrate that the addition of Ge in poly-Si gate results in 1) Fermi-level unpinning with >200 mV increase in work function; 2) improved dielectrics integrity: such as decreased 1/f and generation-recombination noise, improved channel interface, reduced gate leakage, and superior NBTI characteristics. The above experimental observations are correlated to oxygen vacancies related defects in the HfSiON layer