Extremely-Low Threshold Voltage FinFET for 5G mmWave Applications

An optimized doping process is used to achieve extremely-low threshold voltage (ELVT) FinFETs for low-power mmWave applications based on 12nm node technology platform. With the
$V_{TH}\approx 100$
mV ELVT FinFET shows 15%
$I_{EFF}$
improvement at the same
$V_{DD}$
compared to its super-low threshold voltage (SLVT) counterpart, while mismatch and reliability performances are comparable.
$F_{T}/F_{MAX}$
of ~305GHz/~315GHz and comparable Maximum Stable Gain (
MSG
) to SLVT FinFET gives ELVT FinFET an advantage for mmWave 5G low-power applications. Local oscillator (LO) chain blocks are investigated as a circuit level example to confirm the benefits of ELVT FinFET. An optimized LO transmission Line (TL) driver using ELVT FinFETs results in ~9% and ~8% reduction in
$V_{DD}$
and power consumption respectively at the same phase-noise (PN) level as the SLVT based design. If operated at the same
$V_{DD}$
of 0.525V ELVT FinFET can improve the VCO Figure of Merit (
$FOM_{VCO}$
) by ~2.8dB.