Impact of Nitrogen on PBTI Characteristics of HfSiON/TiN Gate Stacks

The impact of nitrogen on charge trapping induced positive bias temperature instability (PBTI) characteristics in HfSiON/TiN gate stacks is investigated. While thickness is found to be the primary parameter to reduce charge trapping, plasma nitrogen reduces PBTI effects in thick (2.7 nm) HfSiON films. Thin films (1.8 nm) show significantly lower threshold voltage (V
_TH
) shift than thick films and seem to be insensitive to N content. Thermal nitridation exacerbates the PBTI effects more than plasma nitridation