An analytic current-voltage model for quasi-ballistic III-nitride high electron mobility transistors

Kexin Li, Shaloo Rakheja

Research output: Contribution to journalArticle

Abstract

We present an analytic model to describe the DC current-voltage (I-V) relationship in scaled III-nitride high electron mobility transistors (HEMTs) in which transport within the channel is quasi-ballistic in nature. Following Landauer's transport theory and charge calculation based on two-dimensional electrostatics that incorporates negative momenta states from the drain terminal, an analytic expression for current as a function of terminal voltages is developed. The model interprets the non-linearity of access regions in non-self-aligned HEMTs. Effects of Joule heating with temperature-dependent thermal conductivity are incorporated in the model in a self-consistent manner. With a total of 26 input parameters, the analytic model offers reduced empiricism compared to existing GaN HEMT models. To verify the model, experimental I-V data of InAlN/GaN with InGaN back-barrier HEMTs with channel lengths of 42 and 105 nm are considered. Additionally, the model is validated against numerical I-V data obtained from DC hydrodynamic simulations of an unintentionally doped AlGaN-on-GaN HEMT with 50-nm gate length. The model is also verified against pulsed I-V measurements of a 150-nm T-gate GaN HEMT. Excellent agreement between the model and experimental and numerical results for output current, transconductance, and output conductance is demonstrated over a broad range of bias and temperature conditions.

Original languageEnglish (US)
Article number184501
JournalJournal of Applied Physics
Volume123
Issue number18
DOIs
StatePublished - May 14 2018

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high electron mobility transistors
ballistics
nitrides
electric potential
direct current
transport theory
output
Joule heating
transconductance
thermal conductivity
nonlinearity
hydrodynamics
electrostatics
momentum
temperature

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

An analytic current-voltage model for quasi-ballistic III-nitride high electron mobility transistors. / Li, Kexin; Rakheja, Shaloo.

In: Journal of Applied Physics, Vol. 123, No. 18, 184501, 14.05.2018.

Research output: Contribution to journalArticle

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