Electron microscopy analysis of dislocation behavior in HVPE-AlGaN layer grown on a stripe-patterned (0001) sapphire substrate

Kuwano, Noriyuki; Kugiyama, Yuta; Nishikouri, Yutaka; Sato, Tadashige; Usui, Akira

doi:10.1016/j.jcrysgro.2009.01.049

Cited by 8 publications

(4 citation statements)

References 4 publications

(4 reference statements)

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“…5(b). 18) The Al 0:06 Ga 0:94 N/GaN SLS is more effective to block screw type of dislocations than that of edge type of dislocations as penetration of most of the screw dislocation lines are blocked at the ML/SLS interface and lower region of the SLS layer, compared to that of edge dislocations which exceeds into the middle and upper region of the SLS layer before inclination. Threading dislocation density (TDD) along the upper edge of the Al 0:06 Ga 0:94 N/GaN SLS cladding layer is estimated to be 3:4 Â 10 9 for screw and mixed component of TD under g ¼ ð0002Þ diffraction condition, and 6:5 Â 10 9 for edge and mixed component of TD under g ¼ ð11…”

Section: Resultsmentioning

confidence: 99%

Effect of Al_0.06Ga_0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer

Shuhaimi¹,

Watanabe²,

Egawa³

2010

Jpn. J. Appl. Phys.

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We report effect of the insertion of Al0.06Ga0.94N/GaN strained-layer superlattices (SLSs) cladding underlayer to InGaN-based multi-quantum well (MQW) structure grown on Si(111) substrate with AlN/GaN intermediate layer. The Al0.06Ga0.94N/GaN SLS underlayer improves emission wavelength uniformity and shows a narrower emission full-width at half-maximum (FWHM) than that of conventional GaN underlayer. A Gaussian fitting was performed to photoluminescence (PL) spectra to obtain emission wavelength behavior and integrated intensity of the peak energy. A higher MQW internal quantum efficiency (ηiqe) of 29.4% is obtained in sample with Al0.06Ga0.94N/GaN SLS underlayer than that of 20.6% in GaN underlayer. Transmission electron microscopy (TEM) analysis indicates that the Al0.06Ga0.94N/GaN SLS layer abruptly bends threading dislocation lines thus reduces threading dislocation density to the MQW. Reciprocal space mapping (RSM) suggests that compressive strain in the GaN portion of Al0.06Ga0.94N/GaN SLS forces the abrupt inclination of the threading dislocations.

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Section: Resultsmentioning

confidence: 99%

Effect of Al_0.06Ga_0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer

Shuhaimi¹,

Watanabe²,

Egawa³

2010

Jpn. J. Appl. Phys.

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“…Then the paired TDs bend to come close to each other with the growth of thin film and are finally merged to be annihilated. The bending mechanism was discussed by Speck's research group [5,6] as well as the present authors' research group [7,8]. As shown in Fig.…”

Section: Resultsmentioning

confidence: 71%

Evidence for moving of threading dislocations during the VPE growth in GaN thin layers

Kuwano

Miyake

Hiramatsu

et al. 2011

Phys. Status Solidi C

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Cross‐sectional transmission electron microscope (TEM) observation was performed in detail to analyze the morphology of threading dislocations (TDs) in GaN thin layers with various thicknesses. The GaN layers were overgrown on an Al0.28Ga0.72N layer by the metal‐organic vapor‐phase epitaxy (MOVPE) method. In a GaN layer about 50 nm in thickness, TDs running up in the AlGaN layer pass into the GaN layer and most of them reach the top surface without bending. In thicker GaN layers, on the other hand, many of TDs form a hairpin‐configuration on or above the interface of GaN and AlGaN to be annihilated. This difference in morphology of TDs indicates that the TDs have moved down inside the GaN layer. Since the formation of hairpins is attributed to a stress‐relief, there should be an extra half‐plane between the paired TDs. Therefore, the movement of TDs should be of “climb motion”. Another example of possible TD movement inside a GaN layer is also described. It is emphasized that the possibility of TD‐movements inside the thin film crystal during the growth should be taken into account in analysis of thin‐layer growth through the behavior of TDs (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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“…They also investigated the effect of the total pressure, V/III ratio, and substrate miscut direction on the growth of AlGaN on a trench-shaped PSS [ 11 , 12 ]. Kuwano et al showed that the main problem in ELOG is predominantly caused by the grain growth along different orientations on the sidewalls of the patterned substrates [ 13 ]. Richter et al discussed the growth behavior of an Al 0.3 Ga 0.7 N layer grown on a honeycomb-shaped PSS [ 14 ].…”

Section: Introductionmentioning

confidence: 99%

Reduction of Defects in AlGaN Grown on Nanoscale-Patterned Sapphire Substrates by Hydride Vapor Phase Epitaxy

et al. 2017

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In this study, a 3-μm-thick AlGaN film with an Al mole fraction of 10% was grown on a nanoscale-patterned sapphire substrate (NPSS) using hydride vapor phase epitaxy (HVPE). The growth mechanism, crystallization, and surface morphology of the epilayers were examined using X-ray diffraction, transmission electron microscopy (TEM), and scanning electron microscopy at various times in the growth process. The screw threading dislocation (TD) density of AlGaN-on-NPSS can improve to 1–2 × 109 cm−2, which is significantly lower than that of the sample grown on a conventional planar sapphire substrate (7 × 109 cm−2). TEM analysis indicated that these TDs do not subsequently propagate to the surface of the overgrown AlGaN layer, but bend or change directions in the region above the voids within the side faces of the patterned substrates, possibly because of the internal stress-relaxed morphologies of the AlGaN film. Hence, the laterally overgrown AlGaN films were obtained by HVPE, which can serve as a template for the growth of ultraviolet III-nitride optoelectronic devices.

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Electron microscopy analysis of dislocation behavior in HVPE-AlGaN layer grown on a stripe-patterned (0001) sapphire substrate

Cited by 8 publications

References 4 publications

Effect of Al_0.06Ga_0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer

Effect of Al_0.06Ga_0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer

Evidence for moving of threading dislocations during the VPE growth in GaN thin layers

Reduction of Defects in AlGaN Grown on Nanoscale-Patterned Sapphire Substrates by Hydride Vapor Phase Epitaxy

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Electron microscopy analysis of dislocation behavior in HVPE-AlGaN layer grown on a stripe-patterned (0001) sapphire substrate

Cited by 8 publications

References 4 publications

Effect of Al0.06Ga0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer

Effect of Al0.06Ga0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer

Evidence for moving of threading dislocations during the VPE growth in GaN thin layers

Reduction of Defects in AlGaN Grown on Nanoscale-Patterned Sapphire Substrates by Hydride Vapor Phase Epitaxy

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Effect of Al_0.06Ga_0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer

Effect of Al_0.06Ga_0.94N/GaN Strained-Layer Superlattices Cladding Underlayer to InGaN-Based Multi-Quantum Well Grown on Si(111) Substrate with AlN/GaN Intermediate Layer