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

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.