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 VTH ≈ 100mV ELVT FinFET shows 15% IEFF improvement at the same VDD compared to its super-low threshold voltage (SLVT) counterpart, while mismatch and reliability performances are comparable. FT/FMAX 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 VDD 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 (FOMVCO) by 2.8dB.