狄拉克源场效应晶体管中的耗散输运与自加热效应

Dirac-source FETs (DSFETs) are considered as a promising candidate for future low-power electronics. However, the impacts of the electron–phonon (e–ph) scattering effect and the self-heating effect (SHE) on subthreshold swing (SS) and the electron current have not been addressed thoroughly. In this article, we investigate the e–ph scattering effect and SHE in DSFETs using nonequilibrium Green’s function (NEGF) method. We simulate a specific DSFET using MoS2 as the channel and the drain material. The results show that the SS of the DSFET is degraded by the e–ph scattering from 48 to 58 mV/decade at bias voltage V _ d=0.5 V, and the ON-state current is degraded by the e–ph scattering about 5%. SHE has almost no effect on the SS and the ON-state current. The degradation of SS by e–ph scattering is attributed to the thermionic emission of carriers at the drain end, rendering the Dirac source less effective. We also present a comparative analysis between the DSFET and the MoS2-FET, and SHE in MoS2-FET is severer than that in DSFET even with smaller ON-state current. A detailed examination of the effects of overlap length in the DSFET and the energy gap of the source graphene on SS and current performance is also presented.