Analog/RF Performance Investigation of Dopingless FET for Ultra-Low Power Applications

In this paper, we investigated the performance of a dopingless (DL) double gate field-effect transistor (DL-DGFET) for ultra-low power (ULP) analog/RF applications. It is observed that the source/drain metal electrode workfunction engineering in DL-DGFET yields improved analog/RF performance as compared to underlap inversion mode (IM) and junctionless (JL) DGFETs. The DL-DGFET exhibits superior electrostatic control, low threshold voltage variability, simpler fabrication process, and comparable ON state current as compared to IM- and JL-DGFETs. In addition, the DL-DGFET alleviates the inherent contradictory trade-off between gain and bandwidth by exhibiting the simultaneous improvement in intrinsic voltage gain ( A_{vo} ) and unity gain cutoff frequency ( f_{T} ). The well calibrated TCAD simulation results of the DL-DGFET show a minimum noise figure ( \text{NF}_{min} ) 1.27 times and 2.29 times less than the IM and JL-DGFET. At gate overdrive voltage of 0.1 V, the DL-DGFET achieves 5.08 times f_{T} and 5.86 times maximum oscillation frequency ( f_{MAX} ) along with 3.59 times A_{vo} in comparison to JL-DGFET. From simulation results, it is evident that the dopingless FET is a promising candidate for ultra-low power applications of analog and radio frequency (RF) domains.