Abstract

AlGaN/GaN high-electron mobility transistors (HEMTs) are a very promising technology for switching and radio frequency power applications due to the high saturation velocity and large breakdown field of the GaN material. However, the electrical reliability of this material system in both the on and the off-state operation regimes is still a fundamental problem to be solved before the widespread use of this technology can be made. In the present work, an electro-thermal particle based device simulator has been developed for a GaN HEMT structure. It consists of a Monte Carlo-Poisson solver which is self consistently coupled with an energy balance solver for both the acoustic and optical phonons. We observe that for a given drain bias, the lattice temperature increases to its steady state value after several iterations (Gummel cycles), whereas the electron temperature starts reducing. This implies that the velocity of the carriers is degrading with the temperature increase which, in turn, degrades the on-current. It is also observed that the lattice temperature and electron temperature are highest near the gate to drain transition region as the carrier velocity is highest in this region. The incorporation of self-heating effects in the model leads to higher electric fields at the gate-drain extension which, in turn, can contribute towards larger charge trapping at the surface and a possibility of formation of pits and cracks, thus leading to reliability concerns.

Original languageEnglish (US)
Pages (from-to)129-136
Number of pages8
JournalJournal of Computational Electronics
Volume11
Issue number1
DOIs
StatePublished - Mar 2012

Fingerprint

High electron mobility transistors
high electron mobility transistors
Heating
Electron temperature
Electron
heating
Charge trapping
electron energy
Phonons
Energy balance
Temperature
temperature
AlGaN
Simulators
Acoustics
Electric fields
simulators
Energy Balance
Cracks
iteration

Keywords

  • Bias polarization
  • Current collapse
  • GaN HEMTs
  • Self-heating

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Modeling and Simulation

Cite this

Is self-heating responsible for the current collapse in GaN HEMTs? / Padmanabhan, Balaji; Vasileska, Dragica; Goodnick, Stephen.

In: Journal of Computational Electronics, Vol. 11, No. 1, 03.2012, p. 129-136.

Research output: Contribution to journalArticle

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