Journal of Computational Electronics

, Volume 14, Issue 3, pp 754–761 | Cite as

Modeling and simulation of oxide dependent 2DEG sheet charge density in AlGaN/GaN MOSHEMT

  • R. Swain
  • J. Panda
  • K. Jena
  • T. R. Lenka


Oxide dielectric present in metal oxide semiconductor high electron mobility transistor plays an important role during formation of two dimensional electron gas (2DEG). The sheet charge concentration \((\hbox {n}_{{\mathrm{s}}})\) is dependent on the Eigenenergy states present in triangular quantum well at AlGaN/GaN interface. The energy states are in fact functions of vertical electric field at the edge of the well. Therefore in this paper a model is developed to find out Electric field and flat-band voltage \((\hbox {V}_{{\mathrm{T}}})\) by adopting energy band approach to incorporate oxide parameters in it unlike the conventional method of solving Poisson’s equation, which is the uniqueness of this paper. The Eigenenergy states are dependent non-linearly on electric field. In the present case, three quantum states in the well are considered along with the Fermi–Dirac distribution function to obtain \(\hbox {n}_{\mathrm{s}}\). The dependence of 2DEG density, electric field and flat-band voltage on the oxide parameters such as thickness and electrical permittivity is analyzed. With respect to thickness in \(\hbox {SiO}_{2}\) and \(\hbox {Al}_{2}\hbox {O}_{3},\, \hbox {n}_{\mathrm{s}}\) shows inverse relationship; whereas in \(\hbox {HfO}_{2}\) it is direct due to positive charges accumulated at oxide/barrier interface. To the best of author’s knowledge the work is first of its kind and due to lack of experimental data; the obtained results are compared with TCAD results to validate the model.


2DEG AlGaN/GaN Eigenenergy MOSHEMT TCAD 



The authors acknowledge the Microelectronics Computational Lab in Department of Electronics & Communication Engineering of National Institute of Technology Silchar, India for providing all necessary facilities to carry out the research work.


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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Microelectronics and VLSI Design Group, Department of Electronics and Communication EngineeringNational Institute of TechnologySilcharIndia

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