Linearity Distortion Analysis of III–V and Si Quadruple Gate Field Effect Transistor (QG-FET) for Analog Applications

Abstract

In this work, analog and linearity distortion performance of a III–V AlGaN/GaN quadruple gate field effect transistor (III–V QG-FET) has been analyzed and compared with conventional Si QG-FET having identical physical dimensions. Specifically, we investigate the linearity by numerically computing transconductance (gm1), its second and third order derivatives (gm2 and gm3), along-with linearity metrics comprising of third order intermodulation distortion (IMD3), third order input intercept point (IIP3), and extrapolated input voltages (VIP2 and VIP3). The consequences of variations in physical parameters of III–V QG-FET, i.e., channel length, channel height, the thickness of oxide layer, doping concentration, along-with temperature on the linearity metrics parameters, drain current, and threshold voltage are analyzed and compared with Si QG-FET. The gate capacitance and dynamic power dissipation is calculated numerically and compared by performing small signal AC analysis at 1 MHz frequency for III–V and Si QG-FETs. The influence of variations in above mentioned physical parameters is also analyzed on dynamic power dissipation and gate capacitance considering the effects of quantum capacitance in the nanometer regime. The present analysis reveals that in III–V QG-FET, the dynamic power dissipation is considerably reduced than its contender Si QG-FET due to its reduced threshold voltage, and thus it is a more promising candidate for analog and low power dissipation applications.