New structure of dual-material gate approach to suppress random-dopant-induced characteristic fluctuation in 16 nm metal-oxide- semiconductor field-effect-transistor devices

In this work, we for the first time explore the dual-material gate (DMG), inverse DMG devices and the optimization of DMG devices for suppressing the random-dopant (RD)-induced characteristic fluctuation in 16 nm metal-oxide-semiconductor field effect transistor (MOSFET) devices. The physical mechanism of suppressing the characteristic fluctuation of DMG devices and structure optimization are observed and discussed. The results show that an optimized DMG device with 60% higher workfunction and 40% lower workfunction in gate area ratio has the best performance to suppress the fluctuation, compared to known DMG devices. The achieved structure exhibits 30.2%, 20% and 9.8% improvements in suppressing threshold voltage, on-state current, and off-state current fluctuations, respectively. Therefore, adjusting the ratio between higher and lower workfunction materials of DMG devices can achieve good immunity to characteristic fluctuation of 16-nm MOSFET devices.