Photoionization spectroscopy in AlGaN/GaN high electron mobility transistors

Klein, P. B.

doi:10.1063/1.1510564

Cited by 28 publications

(19 citation statements)

References 16 publications

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“…Since the conducting channel in a HEMT device is a 2DEG, this approach must be altered slightly in order to model the effect of hot carrier injection on the device output characteristics. The approach taken here follows that of [8].…”

Section: Analytical Modelmentioning

confidence: 99%

Photoionization spectroscopy of deep defects responsible for current collapse in nitride-based field effect transistors

Klein

Binari

2003

J. Phys.: Condens. Matter

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This review is concerned with the characterization and identification of the deep centres that cause current collapse in nitride-based field effect transistors. Photoionization spectroscopy is an optical technique that has been developed to probe the characteristics of these defects. Measured spectral dependences provide information on trap depth, lattice coupling and on the location of the defects in the device structure. The spectrum of an individual trap may also be regarded as a 'fingerprint' of the defect, allowing the trap to be followed in response to the variation of external parameters. The basis for these measurements is derived through a modelling procedure that accounts quantitatively for the light-induced drain current increase in the collapsed device. Applying the model to fit the measured variation of drain current increase with light illumination provides an estimate of the concentrations and photoionization cross-sections of the deep defects. The results of photoionization studies of GaN metal-semiconductor field effect transistors and AlGaN/GaN high electron mobility transistors (HEMTs) grown by metal-organic chemical vapour deposition (MOCVD) are presented and the conclusions regarding the nature of the deep traps responsible are discussed. Finally, recent photoionization studies of current collapse induced by short-term (several hours) bias stress in AlGaN/GaN HEMTs are described and analysed for devices grown by both MOCVD and molecular beam epitaxy. Contents

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Section: Analytical Modelmentioning

confidence: 99%

Photoionization spectroscopy of deep defects responsible for current collapse in nitride-based field effect transistors

Klein

Binari

2003

J. Phys.: Condens. Matter

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“…3 Photoionization spectroscopy Photoionization spectroscopy is a technique which allows to investigate the traps responsible for the current collapse process [5]. By illumination with monochromatic subband gap light trapped carriers are released and so the collapsed drain current restores partially due to optical excitation.…”

Section: Devicesmentioning

confidence: 99%

Investigation of traps in AlGaN/GaN HEMTs on silicon substrate

Wolter

Marso

Javorka

et al. 2003

phys. stat. sol. (c)

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PACS 68.55. Ln, 71.55.Eq, 73.20.Hb, 85.30.Tv Deep levels in AlGaN/GaN heterostructures are known to be responsible for trapping processes like current collapse or dispersion. In order to investigate these processes we performed different measurements on HEMTs fabricated with heterostructures grown on silicon substrate. First by photoionization spectroscopy we found three different traps with activation energies of about 2.1 eV, 2.9 eV and 3.2 eV. Secondly, the temperature dependent relaxation of the drain current was investigated by the backgating current deep level transient spectroscopy (DLTS) method. Hereby we detected majority and minority carrier traps in the GaN buffer at the energies E V + 0.41 eV and E C -0.55 eV, respectively. The latter energy can be attributed to the well known "E2" level in GaN.

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“…Additionally, novel device structures with gate field plates have also been reported to be effective in decreasing the current collapses by modifying the electric field at the gate edges [3]. Nevertheless, the current collapses have not yet been completely eliminated, and there is a strong need to investigate deep-level defects in the bulk region of AlGaN/GaN heterostructures from the viewpoint of 2DEG carrier trapping [4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 98%

Deep-level defects and turn-on capacitance recovery characteristics in AlGaN/GaN heterostructures

Nakano

Irokawa

Sumiya

2015

Philosophical Magazine Letters

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We report on turn-on capacitance recovery measurements as a simple shorttime method of evaluating carrier-trapping phenomena in a two-dimensional electron gas (2DEG) in the bulk region of AlGaN/GaN heterostructures, employing their Schottky barrier diodes. Using this technique, we have investigated an in-depth relation between deep-level defects and 2DEG carrier trapping in an AlGaN/GaN heterostructure with a GaN buffer layer containing a high C concentration. Steady-state photo-capacitance spectroscopy measurements revealed three C-related deep-level defects located at~2.07,~2.80 and 3.23 eV below the conduction band in the GaN buffer layer. Additionally, turn-on capacitance recovery measurements showed a large decrease in recovery time under white-light optical illuminations with long-pass filters between 370 and 390 nm. It is concluded that the~3.23 eV level is mainly responsible for the 2DEG carrier-trapping phenomena in the GaN buffer layer of the AlGaN/GaN heterostructure.

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Photoionization spectroscopy in AlGaN/GaN high electron mobility transistors

Cited by 28 publications

References 16 publications

Photoionization spectroscopy of deep defects responsible for current collapse in nitride-based field effect transistors

Photoionization spectroscopy of deep defects responsible for current collapse in nitride-based field effect transistors

Investigation of traps in AlGaN/GaN HEMTs on silicon substrate

Deep-level defects and turn-on capacitance recovery characteristics in AlGaN/GaN heterostructures

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