Detection of edge component of threading dislocations in GaN by Raman spectroscopy

Kokubo, Nobuhiko; Tsunooka, Yosuke; Fujie, Fumihiro; Ohara, Junji; Hara, Kimiko; Onda, Shoichi; Yamada, Hisashi; Shimizu, Mitsuaki; Harada, Shunta; Tagawa, Miho; Ujihara, Toru

doi:10.7567/apex.11.061002

Cited by 17 publications

(34 citation statements)

References 30 publications

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“…No contrast can be seen at the location (circled by dashed lines) where the TD‐A and TD‐B were observed via XRT. The contrast in the Raman peak shift mapping image was induced by the edge component of the strain field (TEDs or TMDs) . When isotropic strain is applied to the crystal, the E 2 H peak shifts to a higher wavenumber side due to compressive strain and shifts to a lower wavenumber side due to tensile strain.…”

Section: Resultsmentioning

confidence: 99%

“…Raman scattering spectroscopy measurements were obtained using the inVia Raman system (Renishaw plc). Raman mapping was performed by shifting the focal point in 0.5 μm steps to obtain the peak shift of the E 2 H mode in the GaN crystal within 0.1 cm −1 . The laser intensity was maximized at ≈150 mW to reduce the influence of noise.…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, in this study, peak shift mapping by Raman spectroscopy was used as an alternative evaluation method. Our research group succeeded in identifying the edge component of the strain field caused by TEDs and TMDs using Raman spectroscopy . The direction of b in the c ‐plane of GaN can then be determined via an analysis of the strain field of the edge component; because of the compressive and tensile strains that can increase the positives and negatives of the peak shifts in Raman spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

“…The direction of b in the c ‐plane of GaN can then be determined via an analysis of the strain field of the edge component; because of the compressive and tensile strains that can increase the positives and negatives of the peak shifts in Raman spectroscopy. These Raman mapping images can then be compared with the XRT images previously described, allowing nondestructive classification of TDs in GaN crystals …”

Section: Introductionmentioning

confidence: 99%

“…Methods for evaluating TDs in GaN include potassium hydroxide (KOH) etching, transmission electron microscope (TEM), X‐ray topography (XRT), peak shift mapping using Raman spectroscopy, photoluminescence (PL) imaging, cathodoluminescence (CL) mapping, scanning electron microscope (SEM), and multiphoton photoluminescence (MPPL) . Any one of these methods can be used, depending on its advantages and disadvantages for a given research problem.…”

Section: Introductionmentioning

confidence: 99%

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Behavior of Threading Dislocations from GaN Substrate to Epitaxial Layer

Inotsume

Kokubo

Yamada

et al. 2020

Physica Status Solidi (b)

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Threading dislocations (TDs) in the GaN substrate and homoepitaxial layer are nondestructively evaluated using X‐ray topography (XRT), Raman spectroscopy, and multiphoton photoluminescence (MPPL) imaging. When the XRT and Raman mapping images are compared, TDs in the GaN substrate are identified as threading edge dislocations (TEDs), threading mixed dislocations (TMDs), and threading screw dislocations (TSDs). TDs are observed to propagate from the GaN substrate to the epitaxial layer. From MPPL imaging, the TEDs are found to be inclined in the [1true1¯00] direction, which is at 90° from the Burgers vector. The TMD studied in detail is found to be inclined in the [true1¯2true1¯0] direction, which is parallel to the Burgers vector. The feasibility of identifying TDs via analysis of the inclined direction of the dislocations in the GaN epitaxial layer is suggested.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Behavior of Threading Dislocations from GaN Substrate to Epitaxial Layer

Inotsume

Kokubo

Yamada

et al. 2020

Physica Status Solidi (b)

Self Cite

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Identifying threading dislocation types in ammonothermally grown bulkα-GaN by confocal Raman 3-D imaging of volumetric stress distribution

Holmi

Bairamov

Suihkonen

et al. 2018

Journal of Crystal Growth

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Study of High-Quality GaN Growth and Fracture Mechanisms: Insights from Molecular Dynamics

Li,

Gao,

Gao

et al. 2023

Crystal Growth & Design

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Most materials exhibit polymorphism; i.e., their crystallization capacity and behavior are different in different crystal structures. Thus, understanding the material microstructure, particularly the growth behavior of the crystal nucleus, is essential for generating highperformance gallium nitride (GaN) devices. In this study, the inhomogeneity of spontaneous nucleation in the pure liquid system and the growth patterns of GaN crystal nuclei with different structures were studied by a molecular dynamics method. The formation mechanisms of voids and lamellar structures which also appeared in the experimental preparation were analyzed. The lamellar structure formation was largely attributed to the diversity of the nucleus in the early crystallization stage. Introducing crystal nuclei to reduce the structural complexity is beneficial in improving the crystal quality. The morphology and growth rate of the zinc blende and wurtzite crystal nuclei were in great difference. Compared with defects, the dislocation of the pure liquid system was in continuous increase, while the dislocation of the crystal core system was in three states: rapid increase, slow decrease, and dynamic equilibrium. In the mechanical processing, unlike the fracture mechanism of a pure liquid system dominated by voids, continuous grain boundaries or the dislocation entanglement surface were the main reasons for the fracture of the crystal nuclei system. This study further investigated GaN spontaneous nucleation, growth patterns of the crystal nuclei, defect evolution, and the fracture mechanisms on the atomic scale, contributing to the preparation and mechanical processing of high-quality GaN.

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Detection of edge component of threading dislocations in GaN by Raman spectroscopy

Cited by 17 publications

References 30 publications

Behavior of Threading Dislocations from GaN Substrate to Epitaxial Layer

Behavior of Threading Dislocations from GaN Substrate to Epitaxial Layer

Identifying threading dislocation types in ammonothermally grown bulkα-GaN by confocal Raman 3-D imaging of volumetric stress distribution

Study of High-Quality GaN Growth and Fracture Mechanisms: Insights from Molecular Dynamics

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