Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering

Kuball, Martin; Demangeot, F.; Frandon, J.; Renucci, M. A.; Sands, H. S.; Batchelder, D. N.; Clur, S.; Briot, Olivier

doi:10.1063/1.123141

Cited by 27 publications

(15 citation statements)

References 13 publications

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“…Ultraviolet excitation wavelengths of 325 nm also allow the study of Al x Ga 1 x N surface properties for aluminium compositions up to x D 0.23. 20,21 Deep-UV micro-Raman spectroscopy is necessary to probe the surface layer of Al x Ga 1 x N films of higher aluminium compositions due to their larger bandgap (using, for example, a frequency-doubled Ar laser (244 nm) as excitation source 22 up to an aluminium composition of x D 0.71). Note that the Al x Ga 1 x N bandgap increases with increasing aluminium composition x.…”

Section: Methodsmentioning

confidence: 99%

Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control

Kuball

2001

Surface & Interface Analysis

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341

127

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The use of micro-Raman spectroscopy to monitor non-invasively GaN, AlGaN and AlN material parameters for process and growth monitoring/control is demonstrated. Concepts to determine the crystalline quality, the stress, the free carrier concentration, the aluminium composition and the temperature from the Raman modes are reviewed. Raman monitoring of processing and growth is illustrated on selected examples: the high-temperature processing of ion-implanted and non-implanted GaN layers, the Raman monitoring of AlGaN/GaN heterostructure field-effect transistors and the in situ Raman monitoring of GaN growth at elevated temperatures. Ultraviolet Raman spectroscopy has been employed to characterize material properties of GaN surface layers and GaN/AlGaN interfaces. Raman mapping is illustrated on bulk AlN crystals to investigate stress fields related to growth striations and defects.

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Section: Methodsmentioning

confidence: 99%

Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control

Kuball

2001

Surface & Interface Analysis

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341

127

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“…5,8,11 There have been few reports about the thermal stability of AlGaN / GaN heterostructures. 12,13 It was found that the HEMT channel temperature increases rapidly with dissipated power and, at 6 W / mm, the temperature reaches ϳ320°C for sapphire substrate. 14 Investigation into the thermal stability of AlGaN / GaN heterostructures is desirable for further device applications.…”

mentioning

confidence: 98%

Enhanced thermal stability of the two-dimensional electron gas in GaN∕AlGaN∕GaN heterostructures by Si3N4 surface-passivation-induced strain solidification

Feng

Zhou

Cai

et al. 2004

Applied Physics Letters

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The plasma-enhanced chemical-vapor-deposited Si3N4 surface passivation layers with high rf (13.56MHz) and low rf (380KHz), were investigated, using the annealing experiment at 500°C in N2 ambient, for their effectiveness in regard to the stability of the two-dimensional electron gas (2DEG) in GaN∕AlGaN∕GaN high-electron-mobility transistor structures. When the unpassivated sample was annealed, as observation using the Hall and high-resolution x-ray diffraction measurements, an irreversible degradation of the 2DEG behavior and a strain relaxation of the AlGaN epilayer occurred. The Si3N4 deposited with high frequency provided superior long-term stability for the sample and showed no change in the 2DEG conductivity and the strain state in AlGaN epilayer after 170h of aging. However, a significant degradation after deposition and a partial recovery of the 2DEG behavior after annealing due to the Si3N4 densification, was found in sample passivated by low-frequency Si3N4. The enhancement of the long-term stability can be explained as a consequence of the strain solidification of the AlGaN epilayer induced by a denser Si3N4 passivation.

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“…Therefore, use of faceted lateral growth has the potential to obtain crack-free thick AlGaN films. The thermal properties of AlGaN have been studied by Kuball et al 62 employing ultraviolet Raman scattering spectroscopy. The degradation pathway of Alo.72Gao.2sN was monitored for hightemperature treatments.…”

Section: Dislocation and Morphology Analysismentioning

confidence: 99%

GROWTH AND ELECTRICAL/OPTICAL PROPERTIES OF Al_xGa_1−xN IN THE FULL COMPOSITION RANGE

Yun

2006

III-Nitride Semiconductor Materials

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The material development of ternary alloy, AlGaN, is key to GaNbased device applications. This chapter includes a technical review of the key issues such as growth techniques suitable for AlGaN, microstructural analyses for extended defects and cracks accompanied with growth on foreign substrates, and the electrical and optical properties of AlGaN epitaxial films. Growth methods for the full range control of AI mole fraction in AlGaN have been introduced, together with a detailed discussion of bowing parameters in association with the determination of alloy band gap as a function of Al mole fraction.

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Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering

Cited by 27 publications

References 13 publications

Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control

Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control

Enhanced thermal stability of the two-dimensional electron gas in GaN∕AlGaN∕GaN heterostructures by Si3N4 surface-passivation-induced strain solidification

GROWTH AND ELECTRICAL/OPTICAL PROPERTIES OF Al_xGa_1−xN IN THE FULL COMPOSITION RANGE

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Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering

Cited by 27 publications

References 13 publications

Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control

Raman spectroscopy of GaN, AlGaN and AlN for process and growth monitoring/control

Enhanced thermal stability of the two-dimensional electron gas in GaN∕AlGaN∕GaN heterostructures by Si3N4 surface-passivation-induced strain solidification

GROWTH AND ELECTRICAL/OPTICAL PROPERTIES OF AlxGa1−xN IN THE FULL COMPOSITION RANGE

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GROWTH AND ELECTRICAL/OPTICAL PROPERTIES OF Al_xGa_1−xN IN THE FULL COMPOSITION RANGE