Impact of Gate Underlap Design on Analog and RF Performance for 20nm Tri-Material Double Gate(TMDG) MOSFET

Ascribed to better immunity to drain induced barrier lowering (DIBL) and enhanced analog/RF performance, tri-material double gate (TMDG) MOSFET proves to be superior over conventional DG MOSFET configurations. On the other hand, further improvement in various short channel effects (SCE) as well as high tolerance in gate misalignment can be achieved by using gate underlap design in typical DG structures. Merging these two features in this work, a TMDG MOSFET design with 20 nm physical gate length is studied for various symmetrical underlap lengths using 2D device simulation. Extensive analysis are performed to investigate notable analog/RF parameters like transconductance (g
_m
), output conductance (g
_d
), intrinsic gain (A
_v
), intrinsic capacitance and cut-off frequency (f
_T
) along with some SCEs like DIBL and subthreshold swing (SS) for various gate underlap designs. Additionally, some of the performance parameters are compared with single material (SM) and double material (DM) DG architectures. Thus this work provides a thorough investigation of the influence of gate material and gate underlap designs for DG MOSFET compatible for analog/RF application.