Investigation of ‘surface donors’ in Al2O3/AlGaN/GaN metal-oxide-semiconductor heterostructures: Correlation of electrical, structural, and chemical properties

M. Ťapajna, R. Stoklas, D. Gregušová, F. Gucmann, K. Hušeková, Haščík, K. Fröhlich, L. Tóth, B. Pécz, F. Brunner, J. Kuzmík

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

III-N surface polarization compensating charge referred here to as ‘surface donors’ (SD) was analyzed in Al2O3/AlGaN/GaN metal-oxide-semiconductor (MOS) heterojunctions using scaled oxide films grown by metal-organic chemical vapor deposition at 600 °C. We systematically investigated impact of HCl pre-treatment prior to oxide deposition and post-deposition annealing (PDA) at 700 °C. SD density was reduced down to 1.9 × 1013 cm−2 by skipping HCl pre-treatment step as compared to 3.3 × 1013 cm−2 for structures with HCl pre-treatment followed by PDA. The nature and origin of SD was then analyzed based on the correlation between electrical, micro-structural, and chemical properties of the Al2O3/GaN interfaces with different SD density (NSD). From the comparison between distributions of interface traps of MOS heterojunction with different NSD, it is demonstrated that SD cannot be attributed to interface trapped charge. Instead, variation in the integrity of the GaOx interlayer confirmed by X-ray photoelectron spectroscopy is well correlated with NSD, indicating SD may be formed by border traps at the Al2O3/GaOx interface.

Original languageEnglish
Pages (from-to)656-661
Number of pages6
JournalApplied Surface Science
Volume426
DOIs
Publication statusPublished - Dec 31 2017

Fingerprint

Chemical properties
Heterojunctions
Structural properties
Electric properties
Metals
Annealing
Organic Chemicals
Organic chemicals
Oxide semiconductors
aluminum gallium nitride
Oxides
Oxide films
Chemical vapor deposition
X ray photoelectron spectroscopy
Polarization

Keywords

  • AlGaN/GaN
  • Interface states
  • MOS-HEMT
  • Surface donors

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

Cite this

Investigation of ‘surface donors’ in Al2O3/AlGaN/GaN metal-oxide-semiconductor heterostructures : Correlation of electrical, structural, and chemical properties. / Ťapajna, M.; Stoklas, R.; Gregušová, D.; Gucmann, F.; Hušeková, K.; Haščík; Fröhlich, K.; Tóth, L.; Pécz, B.; Brunner, F.; Kuzmík, J.

In: Applied Surface Science, Vol. 426, 31.12.2017, p. 656-661.

Research output: Contribution to journalArticle

Ťapajna, M, Stoklas, R, Gregušová, D, Gucmann, F, Hušeková, K, Haščík, Fröhlich, K, Tóth, L, Pécz, B, Brunner, F & Kuzmík, J 2017, 'Investigation of ‘surface donors’ in Al2O3/AlGaN/GaN metal-oxide-semiconductor heterostructures: Correlation of electrical, structural, and chemical properties', Applied Surface Science, vol. 426, pp. 656-661. https://doi.org/10.1016/j.apsusc.2017.07.195
Ťapajna, M. ; Stoklas, R. ; Gregušová, D. ; Gucmann, F. ; Hušeková, K. ; Haščík ; Fröhlich, K. ; Tóth, L. ; Pécz, B. ; Brunner, F. ; Kuzmík, J. / Investigation of ‘surface donors’ in Al2O3/AlGaN/GaN metal-oxide-semiconductor heterostructures : Correlation of electrical, structural, and chemical properties. In: Applied Surface Science. 2017 ; Vol. 426. pp. 656-661.
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