Modeling and Analysis of Double Channel GaN HEMTs Using a Physics-Based Analytical Model

Abstract

In this work, we report the development of a new physics-based analytical model for current and charge characteristics of Double Channel (DC) Gallium Nitride High Electron Mobility Transistors (GaN-HEMTs). The model has at its core the self-consistent calculation of the charge densities, for both upper and lower channels, obtained from a solution of the Schrödinger and Poisson equations. Fermi-Dirac (FD) distribution together with 2D density of states is used for mobile carrier statistics in both the channels. Furthermore, drift-diffusion transport is used to compute the channel current using charge densities at channel extremities. Finally, the model is validated against TCAD simulation and experimental data for a DC-GaN-HEMT. The model, by virtue of its fully physics-based nature, precisely captures the charge screening effect in the lower channel without invoking any empirical clamping functions, unlike prior models, and also possesses the feature of being geometrically scalable.

Deep insight of inter-channel coupling in AlGaN/GaN double channel HEMT and its application in C-ERB2 sensing

“…From the neutrality model as described in figure 1 and vice versa [23]. The energy band's slope signifies quasi-constant electric fields.…”

“…Where, Q g is the gate charge, ( ) n x u l , are charge density in respective layer which can be derived by applying Fermi-Dirac statistics with 2-D density of states (DOS) theory as [23] ⎜…”

“…The enhancement of electrostatic performance is attributed to two factors: the presence of two high carrier concentration channels and the upper-to-lower channel coupling. Additionally, the higher mobility in the lower channel results from its physical separation from the surface [23].…”

Theoretical Studies of 2D Electron Gas Distributions and Scattering Characteristics in Double‐Channel n‐Al0.3Ga0.7N/GaN/i‐AlxGa1−xN/GaN High‐Electron‐Mobility Transistors

“…[16] To comprehend the more potential of such devices, the theoretical model of DC-GaN-HEMTs presenting physical insights of their operation and serving as the guiding attempt for equipment design is important. Although there devote quite efforts aimed at modeling electrical characteristics of SC-GaN HEMTs, [17][18][19] simply a handful of previous reports on rigorous computations of DC-GaN-HEMTs have been performed, [20,21] and DC devices are usually treated as separate heterojunctions, ignoring the channel-to-channel coupling and the progressive process of the internal physics. [22] To the best of our knowledge, the approach coupling the results of the self-consistently solved Schrödinger-Poisson into mobility models to depict electrostatic properties and transport behaviors has not been seen.…”