Modeling of Floating-Body effect on Negative Bias Temperature Instability degradation of double-gate MOSFETs

In this paper, the effect of Floating-Body (FB) on the Negative Bias Temperature Instability (NBTI) degradation of undoped double-gate (DG) MOSFETs is modeled and investigated through solving the one-dimensional (1-D) Poisson´s equation considering the NBTI effect in the inversion region. The accuracy of the model is verified by the finite difference method (FDM). The results of the model are in very good agreement with those of the numerical method. These results show that in FB devices, the accumulation of the NBTI stress generated electrons in the device floating body, leads to a decrease in the body potential, oxide field, and inversion charge and as a result decrease the generation of interface traps and degradation of device. Moreover, in devices with thinner body, the volume density of generated electrons is larger which result in more degradation of the oxide field and inversion charge density in these devices.