Role of e-e scattering in the enhancement of channel hot carrier degradation of deep sub-micron NMOSFETs at high V/sub GS/ conditions

It has been reported in the literature (Rauch et al., 1998; Wang-Ratkovic et al., 1997; Su et al, 1996; Li et al., 1999) that in deep submicron NMOSFETs the worst channel hot carrier (CHC) degradation is not near the peak substrate current (as predicted by the lucky electron model (Hu et al., 1985)), but at the V/sub GS/=V/sub DS/ bias condition. We propose a new CHC model based on an electron-electron scattering induced hot carrier mechanism, that explains the worsening of the HC damage at high V/sub GS/ and agrees well with the HC lifetime measured over the moderate-to-high gate voltage range and a wide L/sub EFF/ range. The predicted quadratic source current dependence of HC lifetime at mid V/sub GS//V/sub DS/, evolving into a cubic dependence at high V/sub GS//V/sub DS/, matches the observed behavior well.