Gate All Around MOSFET With Vacuum Gate Dielectric for Improved Hot Carrier Reliability and RF Performance

In this paper, gate all around (GAA) MOSFET with vacuum gate dielectric is proposed for the first time for improved hot carrier reliability and RF performance. Analog and RF performance of the GAA MOSFET with vacuum gate dielectric (GAA VacuFET) is compared with conventional GAA MOSFET with SiO₂ dielectric, and it is found that GAA VacuFET is superior to SiO₂ dielectric for RF high-speed applications and more immune to the hot carrier damage because of low electric field at the drain side but it has a serious drawback of low on-current and transconductance as compared to SiO₂ dielectric. In order to enhance the on current and transconductance of GAA VacuFET, Gate Electrode engineering and channel doping engineering are used. An analytical model is developed for dual material gate graded channel GAA MOSFET with vacuum gate dielectric (DMG GC VacuFET) and the model is verified with the simulated results. Incorporation of DMG and GC not only enhances digital and analog RF performance of GAA VacuFET but also hot carrier reliability is improved.