Dynamic NBTI characteristics of p-MOSFET with N-plasma SiON Gate Dielectric
In this paper, the dynamic negative bias temperature instability (DNBTI) characteristics of p-MOSFET with N-plasma SiON dielectric are studied. Under dynamic stress, the nearly consistent frequency dependent characteristics of threshold voltage shift (DeltaVth) and interface trap density (DeltaNit) were observed. The results show that the degradation and recovery of DNBTI are still dominated by the generation and passivation of the interfacial traps associated with Si-H bond breaking and released H species diffusion during stress phase and back diffusion of H and repassivation of broken equivSi bonds during passivation phase, which could be depicted by the so-called reaction-diffusion (R-D) model. Meanwhile, the reduced passivation effect with increased stress time was observed, which suggests that the generation and passivation of Nit seems to present a fatigue effect. These observed DNBTI characteristics may relate to the nitrogen trapping effect on the diffusion of H species in SiON dielectric layer