2D Analytical Modeling of Surface Potential for GaAs based Nanowire Gate All Around MOSFET

Abstract

Now-a-days, the development of minimization of device dimension by the improvement of several device structures, among which tunneling field effect transistors (TFETs) play a vital role which reduce various short channel effects (SCEs). In this paper, a GaAs based 2-D analytical model for fully depleted cylindrical gate MOSFET is presented. In this paper, we solve 2D Poisson's equation for GAA MOSFET and derived the expression for surface potential along the channel length with suitable boundary condition. The model is used to study the immunity against SCE offered by the MOSFET structure. Additional the model is used to formulate an analytical expression of the surface potential. Also, the effect of various physical device parameters whose range varies such as for Tube thickness (10nm-1nm), Radius (5-10nm), temperature (100K-700K) on surface potential of the device. The advantages of surface potential are based models to make ease for the upcoming compact MOSFET models. The model has been simulated using MATLAB.

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“…At a fixed drain voltage (V DS ), the subthreshold current increases with the increasing V GS . This improvement in the subthreshold conduction is due to the decrease in the potential across the channel, and hence, minimum channel potential also decreases (magnitude) with the increasing gate voltage [84]. It is worth interesting to note that the curvature of the potential curve starts decreasing with increasing V GS because high gate voltage increases the vertical electric field by a significant amount.…”

“…The number of charge carriers increases with the increasing temperature. Hence, a narrow potential well can be seen at higher temperatures (minimum channel potential keeps on decreasing with the increasing temperature) [84]. Figure 4(b) shows the potential profile across the channel for K bio = 2.1 at different gate voltages (V GS ).…”

“…Changing V DS has a negligible effect on the channel potential variation (especially region A). Increasing V DS will only change the potential barrier at the drainchannel junction; hence, the potential rises near the drain only [84]. It is interesting to note that there is no variation in the potential in region A (near the source) because the potential barrier at the source-channel junction [54] is almost unchanged.…”