Separation of fast and slow NBTI components under long-term stress in pMISFETs with ultra-thin high-k and SiON dielectrics

Fast and slow components of NBTI in ultra-thin (sub-1-nm EOT) HfSiON/SiO₂ and SiON pMISFETs were investigated in detail by using a separation method of the two NBTI components during long-term stress. For both HfSiON and SiON dielectrics, the following results were commonly obtained: 1) fast and slow components have dasiaindependentpsila universalities of the DeltaVth vs. stress-time slope, and 2) the slow component becomes dominant after long-term stress. Therefore, it is likely that basic NBTI mechanisms for both HfSiON/SiO₂ and SiON are very similar. In the HfSiON case, the ploy-Si gate process additionally affects on the behavior of the two components at low electric-field stress. We also discuss the possible origins of the two components.