Reduction of threading dislocation density in AlXGa1−XN grown on periodically grooved substrates

Mochizuki, Shingo; Detchprohm, Theeradetch; Sano, S.; Nakamura, Tetsuya; Amano, Hiroshi; Akasaki, Isamu

doi:10.1016/s0022-0248(01)02128-5

Cited by 11 publications

(11 citation statements)

References 11 publications

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“…However, these methods are not appropriate for AlGaN because the Al-alloys also nucleate on the mask materials [1,63]. Recently, growth on substrates periodically patterned into terraces and trenches has been proven successful to achieve thick, crack-free AlGaN layers [34,64,65], [66]. However this method is liable to the formation of specific micro-domains in the thick AlGaN layers, exhibiting different Al-concentrations [10,11], as will be directly visualized by cross-sectional scanning CL microscopy in the following (Fig.…”

Section: Lateral Seeding Epitaxy Of Algan On Trench Patterned Ganmentioning

confidence: 99%

Optical micro‐characterization of group‐III‐nitrides: correlation of structural, electronic and optical properties

Christen

Riemann

Bertram

et al. 2003

phys. stat. sol. (c)

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For a detailed understanding of complex semiconductor heterostructures and the physics of devices based on them, a systematic determination and correlation of the structural, chemical, electronic, and optical properties on a micro-or nano-scale is essential. Luminescence techniques belong to the most sensitive, non-destructive methods of semiconductor research. The combination of luminescence spectroscopy with the high spatial resolution of a scanning electron microscope, as realized by the technique of cathodoluminescence microscopy, provides a powerful tool for the optical nano-characterization of semiconductors, their heterostructures as well as their interfaces. Additional access to the local electronic and structural properties is provided by micro-Raman spectroscopy, e.g. giving insight into the local free carrier concentration and local stress. In this paper, the properties of group-III-nitrides are investigated by highly spatially and spectrally resolved cathodoluminescence microscopy in conjunction with micro-Raman spectroscopy. Complex phenomena of self-organization and their strong impact on the microscopic and nanoscopic properties of both binary and ternary nitrides are presented. As the ultimate measure of device performance, the microscopic properties of light emitting diodes are assessed under operation. Using microelectroluminescence mapping in the optical microscope as well as in the near field detection mode of a scanning near field optical microscope, the microscopic origin of the macroscopic spectral red shift in light emitting diodes is identified.

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Section: Lateral Seeding Epitaxy Of Algan On Trench Patterned Ganmentioning

confidence: 99%

Optical micro‐characterization of group‐III‐nitrides: correlation of structural, electronic and optical properties

Christen

Riemann

Bertram

et al. 2003

phys. stat. sol. (c)

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“…The development of an Al x Ga 1-x N material with an appropriate composition of Al as a substrate is very important to make high-performance UV region devices because the AlGaN has direct wide bandgaps ranging from 3.4 eV to 6.2 eV [1][2][3][4]. Though there have been reports on UVdevices fabricated by using of AlGaN/GaN heterostructures grown on sapphire substrates, the device performances such as life time, light output power and wavelength are still need to be improved [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Growth and doping of AlGaN and electroluminescence of SAG‐InGaN/AlGaN heterostructure by mixed‐source HVPE

Kim

Ahn

Yang

et al. 2006

Phys. Status Solidi (c)

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The AlxGa1–xN layers on GaN/Al2O3 substrates are grown by mixed‐source hydride vapor phase epitaxy (HVPE) at various temperatures of the source zone. We find source zone temperature dependence of the composition x of AlxGa1–xN layers. Te doping as a new attempt and Si doping in obtaining an n‐type AlGaN layers are performed by putting small amount of Te (or Si) into the Ga‐Al source, respectively. In case of Te‐doped AlGaN (x = 0.16), the carrier concentration is varied from 1.1 x 1018 to 8.0 x 1018/cm3, while in case of Si‐doped one, it is varied from 2.0 x 1016 to 1.1 x 1017/cm3. We find the new results that Te doping is more suitable to get a high n‐type concentration by mixed‐source HVPE. InGaN/GaN multiple quantum wells (MQWs) are grown on the selective area growth (SAG)‐Te‐doped AlGaN and SAG‐Si‐doped AlGaN cladding layer by mealorganic chemical vapour deposition (MOCVD), respectively. Furthermore, we investigate the electroluminescence (EL) properties of SAG‐LEDs of two different cladding layers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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“…However these devices are composed of AlGaN-based III-V nitrides with higher Al content and the large lattice mismatch between GaN and AlGaN degrades the crystalline quality of AlGaN layers. It is difficult that the TDs in AlGaN layers are reduced by the ELO technique because of nucleation of poly-crystals on the mask surface [11][12][13][14]. Furthermore, the AlGaN layer is susceptible to fluctuations of Al content, which lead to fluctuations of the lattice constant and generate the local stress.…”

Section: Introductionmentioning

confidence: 99%

“…In order to fabricate low TD density AlGaN layer, air-bridged structure is effective in avoiding a bad influence from the poly-crystals on the mask surface. The air-bridged AlGaN layers are fabricated on patterned sapphire, patterned GaN on SiC, and patterned GaN on sapphire [12][13][14][15]. Though the fluctuations of Al content are important issues, there are few reports about ELO AlGaN layers.…”

Section: Introductionmentioning

confidence: 99%

Spatially resolved cathodoluminescence study on AlGaN layer fabricated by air‐bridged lateral epitaxial growth

Ishibashi

Kawaguchi

Sugahara

et al. 2004

Physica Status Solidi (b)

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Structural properties of AlGaN layer on the GaN seed layer fabricated by air-bridged lateral epitaxial growth (ABLEG) have been studied by spatially resolved cathodoluminescence (CL) microscopy. The cross-sectional spatially resolved CL images of the ABLEG-AlGaN layer reveal that there are roughly three regions which have different main CL peaks. This result suggests that there are roughly three regions with the different Al contents. Before coalescence of the overgrown AlGaN wings, there are two regions of Al content, such as about 6.5, 10.6%. On the other hand, after coalescence of the wings, the Al content of the AlGaN layer becomes uniform (Al content = 8.9%). These results suggest that the facet growth of the overgrown AlGaN wings causes the modulation of Al content in the ABLEG-AlGaN layer.

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Reduction of threading dislocation density in AlXGa1−XN grown on periodically grooved substrates

Cited by 11 publications

References 11 publications

Optical micro‐characterization of group‐III‐nitrides: correlation of structural, electronic and optical properties

Optical micro‐characterization of group‐III‐nitrides: correlation of structural, electronic and optical properties

Growth and doping of AlGaN and electroluminescence of SAG‐InGaN/AlGaN heterostructure by mixed‐source HVPE

Spatially resolved cathodoluminescence study on AlGaN layer fabricated by air‐bridged lateral epitaxial growth

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