2D analytical modeling and simulation of dual material DG MOSFET for biosensing application

Abstract

In the recent times, the performance of MOSFET in the nanoscaled region attains improvisations through several alternative device structures. Amongst many advanced MOSFET structures, the Double Gate (DG) MOSFET is one such structure which mitigates short channel effects because of its excellent scalability. Among the various structures, FET- based biosensors have shown an accelerated growth recently. Even though many analytical models are available for the Dual Material DG (DMDG) MOSFET structures, this work endeavours to introduce an analytical modeling of nanocavity embedded DMDG structure for the first time. The expression for surface potential is obtained by solving the 2-D Poisson’s equation using a parabolic-potential approach. The threshold voltage is determined from the minimum surface potential model. Sensitivity is computed in terms of relative change in the threshold voltage and it is derived using the model. The influence of various device geometrical parameters like length and thickness of the nanocavity on the sensitivity has been investigated. Further, a comparison of the sensitivity of DG MOSFET and DMDG MOSFET has also been made and the derived results are validated against TCAD simulation results.