A drain extended FinFET with enhanced DC/RF performance for high-voltage RF applications

Abstract A drain-extended fin field-effect transistor (FinFET) with a dual material gate (DMG) and a high- k field plate (FP), named DF-DeFF, is proposed for high-voltage radio frequency (RF) applications. The FP induces the charge variation in the drain extension, which appears as either the extended depletion in the gate-off state or the electron accumulation in the gate-on state. Along with the FP, the DMG forms a step-like potential variation along the channel, which leads to electron acceleration and the screening effect on the drain-to-source voltage ( V DS ). These effects give significant advantages to the DC characteristics, including breakdown voltage ( V BD ) and on-resistance ( R on ), and the RF characteristics, including transconductance ( g m ) and output-resistance ( r o ). Compared to the latest high-voltage RF FinFETs, the DF-DeFF shows a drastic improvement in the major performance indicators such as V BD , cut-off frequency ( f T ), and maximum oscillation frequency ( f MAX ). These results indicate that DF-DeFF is a FinFET with sufficient competitiveness even in high voltage circumstances.