Degradation of Submicron MOSFETs after Aging

Abstract

The degradation is investigated of submicron MOS transistors after electrical stress. New methods for the aging investigation based on field effect mobility measurements are presented. The correlations between the different degradation parameters are studied and analysed by a one-dimensional modelling that takes into account the potential fluctuations induced by the surface state and charge generation. Moreover, the degradations are found to increase with the bias parameter K = Ug/Ud applied during stress. In addition, the partial reversibility of degradations shows that electron trapping appears as the main cause of aging. Ce papier s'interesse a la degradation des transistors MOS apres contrainte electrique. De nouvelles methodes d'investigation du vieillissement basees sur des mesures de mobilite d'effet de champ sont presentees. Les correlations entre les differents parametres de degradation sont etudiees et analysees par un modele uni-dimensionnel qui prend en compte les fluctuations de potentiel induites par la creation d'etats et de charges de surface. De plus, on trouve que les degradations augmentent comme le parametre de contrainte K = Ug/Ud. Enfin, la reversibilite partielle des degradations montre que le piegeage d'electrons apparait comme la cause principale des vicillissements observes.