Abstract: 
In this paper, the surrounding-gate MOSFET model is extended to include the hydrodynamic transport and quantum mechanical effects, and we show that it can reproduce the results of 3D numerical simulations using advanced transport models such as quantum ballistic, semiclassical ballistic, with acoustic phonon and surface roughness. A template device representative for the cylindrical surrounding-gate MOSFET was used to validate the model. Our starting point, in this work is an analytical expression that models the variation of surface potential as well as the difference of potential at the surface and at the middle of the silicon layer. This potential expression obtained is used to derive an analytical compact model for the drain current of a cylindrical surrounding-gate MOSFETs. We extend the model to include hydrodynamic transport and quantum mechanical effects. The DIBL effect is considered through a threshold voltage correction in the model. Using the concept of inversion layer centroid, a correction in the oxide capacitance improves the accuracy in the strong inversion region. Velocity overshoot is modeled through the hydrodynamic transport model. The model takes into account the mobility degradation due to scattering effects. The final compact model includes mobility degradation, drain-induced barrier lowering, overshoot velocity and quantum effects. Comparison between the compact model and 3D advanced transport modeling approaches shows good agreement.

Abstract: 
We present an experimental evaluation of self-heating effects using S-parameter measurements for both N- and P- type SOI FinFETs. It is revealed that NFETs show a stronger self-heating effect than PFETs, which ultimately leads to higher variation of the intrinsic gain in NFETs. Our results also show that long-channel devices typically used in analog design show pronounced negative output conductance, which consequently leads to negative intrinsic gain at low frequencies. Another implication of the strong SHE is that the inter-die variability of the isothermal intrinsic gain gets "amplified" at lower frequencies due to self-heating.