Analytical Modeling of GaN-HEMT Considering Finite Width of Two-Dimensional Electron Gas

Document Type : Research Article


1 Department of Electrical Engineering, Amirkabir University of Technology (Tehran Polytechnique)

2 Amirkabir University of Technology


In this work, we present an analytical DC model for Gallium Nimtide High Electron Mobility Transistor by taking into account the finite width of the two-dimensional electron gas (2DEG) layer. The model predicts the vertical electric field in the device, especially at the interface of AlGaN and GaN layers, electrostatic potential, and energy band diagram are also obtained by the model. The general form of Gauss’s law including piezoelectric and spontaneous polarization effect is employed to obtain this model in different regions from top to bottom of the GaN-HEMT. The model solves electrostatic equations in all regions of the device including two narrow regions around the AlGaN/GaN interface with thicknesses of about 3 nm. This model demonstrates how the triangular quantum well is formed around the AlGaN/GaN interface and varies as a function of gate voltages. Using the proposed electrostatic analysis and the treatment proposed by the EPFL HEMT model, the DC current-voltage characteristics are obtained by this model. The results predicted by the model are validated with TCAD simulations and in part with the EPFL HEMT model. The proposed model facilitates the following steps toward obtaining a complete model for small signal and large signal analysis of GaN HEMT.


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