2-D Theoretical Model for Current–Voltage Characteristics in AlGaN/GaN HEMT’s

Manel Charfeddine, Hafedh Belmabrouk, Mohamed Ali Zaidi, Hassen Maaref

Laboratoire d’électronique et de microélectronique, Département de Physique, Faculté des Sciences de Monastir, Monastir, Tunisia.
Laboratoire de micro-optoélectronique et nanostructures, Département de Physique, Faculté des Sciences de Monastir, Monastir, Tunisia.

DOI: 10.4236/jmp.2012.38115                

Abstract

A threshold-voltage-based 2-D theoretical model for the Current–Voltage characteristics of the AlGaN/GaN high electron mobility transistors (HEMT’s) is developed. The present work proposes an improved charge-control model by employing the Robin boundary condition when introduced the solution of the 2-D Poisson’s equation in the density of charge depleted in the AlGaN layer. The dependence of 2-DEG sheet carrier concentration on the aluminum composition and AlGaN layer thickness has been investigated in detail. Current–voltage characteristics developed from the 2-DEG model in order to take into account the impact of gate lengths. The relation between the kink effect and existing deep centers has also been confirmed by using an electrical approach, which can allow to adjust some of electron transport parameters in order to optimize the output current.

Keywords

AlGaN/GaN; High Electron Mobility Transistors; Two-Dimensional Electron Gas Sheet Charge Density; Current–Voltage Characteristics; Kink Effect

Conflicts of Interest

The authors declare no conflicts of interest.

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