Temperature Dependent Vertical Conduction of GaN HEMT Structures on Silicon and Bulk GaN Substrates

Lars Heuken, Muhammad Alshahed, Alessandro Ottaviani, Mohammed Alomari, Michael Heuken, Clemens Wächter, Thomas Bergunde, Ildikó Cora, Lajos Tóth, Béla Pécz, Joachim N. Burghartz

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1 Citation (Scopus)

Abstract

The vertical leakage current mechanisms of high electron mobility transistors (HEMT) grown by metalorganic chemical vapor deposition (MOCVD) on Si and GaN substrate under forward and reverse bias are analyzed at ambient temperatures from 25 °C to 200 °C. For the GaN/Si case, a thermally activated vertical conduction with two temperature regimes and activation energies of 0.06 eV and 0.43 eV is found. In contrast to that, the GaN/GaN case shows a single activation energy of 0.67 eV for the rate-limited vertical conduction. For forward vertical bias, Poole–Frenkel (PF) conduction is identified as the dominant conduction mechanism at higher fields for both substrates. In reverse bias, space charge limited and PF conduction are identified as dominant conduction mechanism for GaN/Si and GaN/GaN, respectively. The deviation in vertical conduction mechanism is related to a significant reduction in the dislocation density by three orders of magnitude and homoepitaxially lattice matched growth for the GaN/GaN HEMT.

Original languageEnglish
Article number1800482
JournalPhysica Status Solidi (A) Applications and Materials Science
Volume216
Issue number1
DOIs
Publication statusPublished - Jan 9 2019

Keywords

  • GaN HEMT
  • GaN substrates
  • Poole–Frenkel conduction
  • space charge limited current
  • temperature dependent vertical current
  • vertical conduction mechanisms

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering
  • Materials Chemistry

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  • Cite this

    Heuken, L., Alshahed, M., Ottaviani, A., Alomari, M., Heuken, M., Wächter, C., Bergunde, T., Cora, I., Tóth, L., Pécz, B., & Burghartz, J. N. (2019). Temperature Dependent Vertical Conduction of GaN HEMT Structures on Silicon and Bulk GaN Substrates. Physica Status Solidi (A) Applications and Materials Science, 216(1), [1800482]. https://doi.org/10.1002/pssa.201800482