Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching

Joy Dorene McNamara, K. L. Phumisithikul, A. A. Baski, J. Marini, F. Shahedipour-Sandvik, S. Das, M. A. Reshchikov

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The surface photovoltage (SPV) technique was used to study the surface and electrical properties of Mg-doped, p-type AlxGa1-xN (0.06 < x < 0.17) layers. SPV measurements reveal significant deviation from previous SPV studies on p-GaN:Mg thin films and from the predictions of a thermionic model for the SPV behavior. In particular, the SPV of the p-AlGaN:Mg layers exhibited slower-than-expected transients under ultraviolet illumination and delayed restoration to the initial dark value. The slow transients and delayed restorations can be attributed to a defective surface region which interferes with normal thermionic processes. The top 45 nm of the p-AlGaN:Mg layer was etched using a reactive-ion etch which caused the SPV behavior to be substantially different. From this study, it can be concluded that a defective, near-surface region is inhibiting the change in positive surface charge by allowing tunneling or hopping conductivity of holes from the bulk to the surface, or by the trapping of electrons traveling to the surface by a high concentration of defects in the near-surface region. Etching removes the defective layer and reveals a region of presumably higher quality, as evidenced by substantial changes in the SPV behavior.

Original languageEnglish (US)
Article number155304
JournalJournal of Applied Physics
Volume120
Issue number15
DOIs
StatePublished - Oct 21 2016

Fingerprint

photovoltages
etching
ions
thermionics
restoration
surface properties
illumination
trapping
electrical properties

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

McNamara, J. D., Phumisithikul, K. L., Baski, A. A., Marini, J., Shahedipour-Sandvik, F., Das, S., & Reshchikov, M. A. (2016). Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching. Journal of Applied Physics, 120(15), [155304]. https://doi.org/10.1063/1.4964805

Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching. / McNamara, Joy Dorene; Phumisithikul, K. L.; Baski, A. A.; Marini, J.; Shahedipour-Sandvik, F.; Das, S.; Reshchikov, M. A.

In: Journal of Applied Physics, Vol. 120, No. 15, 155304, 21.10.2016.

Research output: Contribution to journalArticle

McNamara, JD, Phumisithikul, KL, Baski, AA, Marini, J, Shahedipour-Sandvik, F, Das, S & Reshchikov, MA 2016, 'Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching', Journal of Applied Physics, vol. 120, no. 15, 155304. https://doi.org/10.1063/1.4964805
McNamara JD, Phumisithikul KL, Baski AA, Marini J, Shahedipour-Sandvik F, Das S et al. Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching. Journal of Applied Physics. 2016 Oct 21;120(15). 155304. https://doi.org/10.1063/1.4964805
McNamara, Joy Dorene ; Phumisithikul, K. L. ; Baski, A. A. ; Marini, J. ; Shahedipour-Sandvik, F. ; Das, S. ; Reshchikov, M. A. / Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching. In: Journal of Applied Physics. 2016 ; Vol. 120, No. 15.
@article{9d3754cd86d647f081674243cf986666,
title = "Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching",
abstract = "The surface photovoltage (SPV) technique was used to study the surface and electrical properties of Mg-doped, p-type AlxGa1-xN (0.06 < x < 0.17) layers. SPV measurements reveal significant deviation from previous SPV studies on p-GaN:Mg thin films and from the predictions of a thermionic model for the SPV behavior. In particular, the SPV of the p-AlGaN:Mg layers exhibited slower-than-expected transients under ultraviolet illumination and delayed restoration to the initial dark value. The slow transients and delayed restorations can be attributed to a defective surface region which interferes with normal thermionic processes. The top 45 nm of the p-AlGaN:Mg layer was etched using a reactive-ion etch which caused the SPV behavior to be substantially different. From this study, it can be concluded that a defective, near-surface region is inhibiting the change in positive surface charge by allowing tunneling or hopping conductivity of holes from the bulk to the surface, or by the trapping of electrons traveling to the surface by a high concentration of defects in the near-surface region. Etching removes the defective layer and reveals a region of presumably higher quality, as evidenced by substantial changes in the SPV behavior.",
author = "McNamara, {Joy Dorene} and Phumisithikul, {K. L.} and Baski, {A. A.} and J. Marini and F. Shahedipour-Sandvik and S. Das and Reshchikov, {M. A.}",
year = "2016",
month = "10",
day = "21",
doi = "10.1063/1.4964805",
language = "English (US)",
volume = "120",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "15",

}

TY - JOUR

T1 - Surface photovoltage studies of p -type AlGaN layers after reactive-ion etching

AU - McNamara, Joy Dorene

AU - Phumisithikul, K. L.

AU - Baski, A. A.

AU - Marini, J.

AU - Shahedipour-Sandvik, F.

AU - Das, S.

AU - Reshchikov, M. A.

PY - 2016/10/21

Y1 - 2016/10/21

N2 - The surface photovoltage (SPV) technique was used to study the surface and electrical properties of Mg-doped, p-type AlxGa1-xN (0.06 < x < 0.17) layers. SPV measurements reveal significant deviation from previous SPV studies on p-GaN:Mg thin films and from the predictions of a thermionic model for the SPV behavior. In particular, the SPV of the p-AlGaN:Mg layers exhibited slower-than-expected transients under ultraviolet illumination and delayed restoration to the initial dark value. The slow transients and delayed restorations can be attributed to a defective surface region which interferes with normal thermionic processes. The top 45 nm of the p-AlGaN:Mg layer was etched using a reactive-ion etch which caused the SPV behavior to be substantially different. From this study, it can be concluded that a defective, near-surface region is inhibiting the change in positive surface charge by allowing tunneling or hopping conductivity of holes from the bulk to the surface, or by the trapping of electrons traveling to the surface by a high concentration of defects in the near-surface region. Etching removes the defective layer and reveals a region of presumably higher quality, as evidenced by substantial changes in the SPV behavior.

AB - The surface photovoltage (SPV) technique was used to study the surface and electrical properties of Mg-doped, p-type AlxGa1-xN (0.06 < x < 0.17) layers. SPV measurements reveal significant deviation from previous SPV studies on p-GaN:Mg thin films and from the predictions of a thermionic model for the SPV behavior. In particular, the SPV of the p-AlGaN:Mg layers exhibited slower-than-expected transients under ultraviolet illumination and delayed restoration to the initial dark value. The slow transients and delayed restorations can be attributed to a defective surface region which interferes with normal thermionic processes. The top 45 nm of the p-AlGaN:Mg layer was etched using a reactive-ion etch which caused the SPV behavior to be substantially different. From this study, it can be concluded that a defective, near-surface region is inhibiting the change in positive surface charge by allowing tunneling or hopping conductivity of holes from the bulk to the surface, or by the trapping of electrons traveling to the surface by a high concentration of defects in the near-surface region. Etching removes the defective layer and reveals a region of presumably higher quality, as evidenced by substantial changes in the SPV behavior.

UR - http://www.scopus.com/inward/record.url?scp=84992415774&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84992415774&partnerID=8YFLogxK

U2 - 10.1063/1.4964805

DO - 10.1063/1.4964805

M3 - Article

VL - 120

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 15

M1 - 155304

ER -