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Smalc-Koziorowska J, Moneta J, Muzioł G, Chromiński W, Kernke R, Albrecht M, Schulz T, Belabbas I. The dissociation of (a+c) misfit dislocations at the InGaN/GaN interface. J Microsc 2024; 293:146-152. [PMID: 37846455 DOI: 10.1111/jmi.13234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 10/18/2023]
Abstract
In hexagonal materials, (a+c) dislocations are typically observed to dissociate into partial dislocations. Edge (a+c) dislocations are introduced into (0001) nitride semiconductor layers by the process of plastic relaxation. As there is an increasing interest in obtaining relaxed InGaN buffer layers for the deposition of high In content structures, the study of the dissociation mechanism of misfit (a+c) dislocations laying at the InGaN/GaN interface is then crucial for understanding their nucleation and glide mechanisms. In the case of the presented plastically relaxed InGaN layers deposited on GaN substrates, we observe a trigonal network of (a+c) dislocations extending at the interface with a rotation of 3° from <11 ¯ $\bar 1$ 00> directions. High-resolution microscopy studies show that these dislocations are dissociated into two Frank-Shockley 1/6<22 ¯ $\bar 2$ 03> partial dislocations with the I1 BSF spreading between them. Atomistic simulations of a dissociated edge (a+c) dislocation revealed a 3/5-atom ring structure for the cores of both partial dislocations. The observed separation between two partial dislocations must result from the climb of at least one of the dislocations during the dissociation process, possibly induced by the mismatch stress in the InGaN layer.
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Affiliation(s)
- J Smalc-Koziorowska
- Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw, Poland
| | - J Moneta
- Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw, Poland
| | - G Muzioł
- Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw, Poland
| | - W Chromiński
- Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland
| | - R Kernke
- Lebniz Institute for Crystal Growth, Berlin, Germany
| | - M Albrecht
- Lebniz Institute for Crystal Growth, Berlin, Germany
| | - T Schulz
- Lebniz Institute for Crystal Growth, Berlin, Germany
| | - I Belabbas
- Equipe de Cristallographie et de Simulation des Matériaux, Laboratoire de Physico-Chimie des Matériaux et Catalyse, Faculté des Sciences Exactes, Université de Bejaia, Bejaia, Algeria
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2
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Yamaguchi Y, Kanitani Y, Kudo Y, Uzuhashi J, Ohkubo T, Hono K, Tomiya S. Atomic Diffusion of Indium through Threading Dislocations in InGaN Quantum Wells. Nano Lett 2022; 22:6930-6935. [PMID: 36048741 PMCID: PMC9480092 DOI: 10.1021/acs.nanolett.2c01479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 08/01/2022] [Indexed: 06/15/2023]
Abstract
The compositional and structural investigations of threading dislocations (TDs) in InGaN/GaN multiple quantum wells were carried out using correlative transmission electron microscopy (TEM) and atom probe tomography (APT). The correlative TEM/APT analysis on the same TD reveals that the indium atoms are diffused along the TD and its concentration decreases with distance from the InGaN layer. On the basis of the results, we directly observed that the indium atoms originating from the InGaN layer diffuse toward the epitaxial GaN surface through the TD, and it is considered to have occurred via the pipe diffusion mechanism induced by strain energy relaxation.
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Affiliation(s)
- Yudai Yamaguchi
- R&D
Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014, Japan
| | - Yuya Kanitani
- R&D
Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014, Japan
| | - Yoshihiro Kudo
- R&D
Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014, Japan
| | - Jun Uzuhashi
- National
Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Tadakatsu Ohkubo
- National
Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Kazuhiro Hono
- National
Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Shigetaka Tomiya
- R&D
Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014, Japan
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3
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Jiang Y, Tan H, Zhao Y. Improving Optical and Electrical Properties of GaN Epitaxial Wafers and Enhancing Luminescent Properties of GaN-Based Light-Emitting-Diode with Excimer Laser Irradiation. Symmetry (Basel) 2021; 13:1935. [DOI: 10.3390/sym13101935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The effect of KrF excimer laser irradiation on the optical and electrical properties of epitaxial wafers with a p-GaN surface were investigated at different laser energy densities and pulse numbers. The laser-irradiated samples were annealed in oxygen. The laser irradiation-induced changes in optical and electrical properties of GaN epitaxial wafers were examined using PL, I–V, XPS, SIMS, and Hall effect measurements. Experimental results show that under an appropriate laser-irradiated condition, optical and electrical properties of the samples were improved to different degrees. The samples which were annealed after laser irradiation have better electrical properties such as the hole concentration and sheet resistance than those without annealing. We hypothesize that the pulsed KrF excimer laser irradiation dissociates the Mg–H complexes and annealing treatment allows the hydrogen to diffuse out more completely under the oxygen atmosphere at a proper temperature, by which the crystalline symmetry of GaN is improved. Under appropriate laser conditions and O2-activated annealing, the light output of the laser-irradiated GaN-based LED sample is about 1.44 times that of a conventional LED at 20 mA. It is found that the wall-plug efficiency is 10% higher at 20 mA and the reverse leakage current is 80% lower at 5 V.
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Yun H, Prakash A, Birol T, Jalan B, Mkhoyan KA. Dopant Segregation Inside and Outside Dislocation Cores in Perovskite BaSnO 3 and Reconstruction of the Local Atomic and Electronic Structures. Nano Lett 2021; 21:4357-4364. [PMID: 33973791 DOI: 10.1021/acs.nanolett.1c00966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Distinct dopant behaviors inside and outside dislocation cores are identified by atomic-resolution electron microscopy in perovskite BaSnO3 with considerable consequences on local atomic and electronic structures. Driven by elastic strain, when A-site designated La dopants segregate near a dislocation core, the dopant atoms accumulate at the Ba sites in compressively strained regions. This triggers formation of Ba vacancies adjacent to the core atomic sites resulting in reconstruction of the core. Notwithstanding the presence of extremely large tensile strain fields, when La atoms segregate inside the dislocation core, they become B-site dopants, replacing Sn atoms and compensating the positive charge of the core oxygen vacancies. Electron energy-loss spectroscopy shows that the local electronic structure of these dislocations changes dramatically due to segregation of the dopants inside and around the core ranging from formation of strong La-O hybridized electronic states near the conduction band minimum to insulator-to-metal transition.
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Affiliation(s)
- Hwanhui Yun
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Abhinav Prakash
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Turan Birol
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Bharat Jalan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - K Andre Mkhoyan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Amichi L, Mouton I, Boureau V, Di Russo E, Vennéguès P, De Mierry P, Grenier A, Jouneau PH, Bougerol C, Cooper D. Correlative investigation of Mg doping in GaN layers grown at different temperatures by atom probe tomography and off-axis electron holography. Nanotechnology 2020; 31:045702. [PMID: 31577995 DOI: 10.1088/1361-6528/ab4a46] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Correlation between off-axis electron holography and atom probe tomography (APT) provides morphological, chemical and electrical information about Mg doping (p-type) in gallium nitride (GaN) layers that have been grown at different temperatures at a nanometric scale. APT allows access to the three-dimensional distribution of atoms and their chemical nature. In particular, this technique allows visualisation of the Mg-rich clusters observed in p-doped GaN layers grown by metal-organic chemical vapour deposition. As the layer growth temperature increases, the cluster density decreases but their size indicted by the number of atoms increases. Moreover, APT reveals that threading dislocations are decorated with Mg atoms. Off-axis electron holography provides complementary information about the electrical activity of the Mg doping. As only a small fraction of dopant atoms are ionised at room temperature, this fraction is increased by annealing the specimen to 400 °C in situ in a transmission electron microscope (TEM). A strong reduction of the dopant electrical activity is observed for increases in the layer growth temperature. The correlation of APT with TEM-based techniques was shown to be a unique approach in order to investigate how the growth temperature affects both the chemical distribution and electrical activity of Mg dopant atoms.
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Affiliation(s)
- Lynda Amichi
- Univ. Grenoble Alpes, CEA, INAC, F-38000 Grenoble, France
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Li S, Lei H, Wang Y, Ullah MB, Chen J, Avrutin V, Özgür Ü, Morkoç H, Ruterana P. Polarity Control within One Monolayer at ZnO/GaN Heterointerface: (0001) Plane Inversion Domain Boundary. ACS Appl Mater Interfaces 2018; 10:37651-37660. [PMID: 30280560 DOI: 10.1021/acsami.8b12202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In semiconductor heterojunction, polarity critically governs the physical properties, with an impact on electronic or optoelectronic devices through the presence of pyroelectric and piezoelectric fields at the active heteropolar interface. In the present work, the abrupt O-polar ZnO/Ga-polar GaN heterointerface was successfully achieved by using high O/Zn ratio flux during the ZnO nucleation growth. Atomic-resolution high-angle annular dark-field and bright-field transmission electron microscopy observation revealed that this polarity inversion confines within one monolayer by forming the (0001) plane inversion domain boundary (IDB) at the ZnO/GaN heterointerface. Through theoretical calculation and topology analysis, the geometry of this IDB was determined to possess an octahedral Ga atomic layer in the interface, with one O/N layer symmetrically bonded at the tetrahedral site. The computed electronic structure of all considered IDBs revealed a metallic character at the heterointerface. More interestingly, the presence of two-dimensional (2D) hole gas (2DHG) or 2D electron gas (2DEG) is uncovered by investigating the chemical bonding and charge transfer at the heterointerface. This work not only clarifies the polarity control and interfacial configuration of the O-polar ZnO/Ga-polar GaN heterojunction but, more importantly, also gives insight into their further application on heterojunction field-effect transistors as well as hybrid ZnO/GaN optoelectronic devices. Moreover, such polarity control at the monolayer scale might have practical implications for heterojunction devices based on other polar semiconductors.
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Affiliation(s)
- Siqian Li
- CIMAP, UMR 6252 CNRS, ENSICAEN, UCBN, CEA , 6 Boulevard du Maréchal Juin , 14050 Caen Cedex, France
| | - Huaping Lei
- Key Laboratory of Materials Physics, Institute of Solid State Physics , Chinese Academy of Sciences , Hefei 230031 , China
| | - Yi Wang
- Max Planck Institute for Solid State Research , Heisenbergstrasse 1 , 70569 Stuttgart , Germany
| | - Md Barkat Ullah
- Department of Electrical and Computer Engineering , Virginia Commonwealth University , Richmond , Virginia 23284 , United States
| | - Jun Chen
- CIMAP, UMR 6252 CNRS, ENSICAEN, UCBN, CEA , 6 Boulevard du Maréchal Juin , 14050 Caen Cedex, France
| | - Vitaliy Avrutin
- Department of Electrical and Computer Engineering , Virginia Commonwealth University , Richmond , Virginia 23284 , United States
| | - Ümit Özgür
- Department of Electrical and Computer Engineering , Virginia Commonwealth University , Richmond , Virginia 23284 , United States
| | - Hadis Morkoç
- Department of Electrical and Computer Engineering , Virginia Commonwealth University , Richmond , Virginia 23284 , United States
| | - Pierre Ruterana
- CIMAP, UMR 6252 CNRS, ENSICAEN, UCBN, CEA , 6 Boulevard du Maréchal Juin , 14050 Caen Cedex, France
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TOKUNAGA T, SAITO K, KUNO K, HIGUCHI K, YAMAMOTO Y, YAMAMOTO T. Removal of carbon contamination in ETEM by introducing Ar during electron beam irradiation. J Microsc 2018; 273:46-52. [DOI: 10.1111/jmi.12759] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 08/02/2018] [Accepted: 09/06/2018] [Indexed: 11/27/2022]
Affiliation(s)
- T. TOKUNAGA
- Department of Quantum EngineeringNagoya University, Furo‐cho chikusa‐ku, Nagoya Aichi Japan
| | - K. SAITO
- Department of Material EngineeringNagoya University, Furo‐cho chikusa‐ku, Nagoya Aichi Japan
| | - K. KUNO
- Department of Quantum EngineeringNagoya University, Furo‐cho chikusa‐ku, Nagoya Aichi Japan
| | - K. HIGUCHI
- Institute of Materials and Systems for SustainabilityNagoya University, Furo‐cho chikusa‐ku, Nagoya Aichi Japan
| | - Y. YAMAMOTO
- Institute of Materials and Systems for SustainabilityNagoya University, Furo‐cho chikusa‐ku, Nagoya Aichi Japan
| | - T. YAMAMOTO
- Department of Quantum EngineeringNagoya University, Furo‐cho chikusa‐ku, Nagoya Aichi Japan
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8
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Abstract
We report the existence of latent order during core relaxation in the high-angle grain boundaries (GBs) of GaN films using atomic-resolution scanning transmission electron microscopy and ab initio density functional theory calculations. Core structures in the high-angle GBs are characterized by two pairs of Ga-N bonds located next to each other. The core type correlates strongly with the bond angle differences. We identify an order of core relaxation hidden in the high-angle GBs by further classifying the 5/7 atom cores into a stable 5/7 core (5/7(S)) and a metastable 5/7 core (5/7(M)). This core-type classification indicates that metastable cores can exist at real high-angle GBs under certain circumstances. Interestingly, 5/7(M) exhibits distinct defect states compared to 5/7(S), despite their similar atomic configurations. We investigate the reconstruction of defect states observed in 5/7(M) by analyzing the real-space wave functions. An inversion occurred between two localized states during the transition from 5/7(S) to 5/7(M). We suggest an inversion mechanism to explain the formation of new defect states in 5/7(M).
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Affiliation(s)
- Sangmoon Yoon
- Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Korea.,Department of Physics and Research Institute for Basic Sciences, Kyung Hee University, Seoul, 02447, Korea
| | - Hyobin Yoo
- Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Korea
| | - Seoung-Hun Kang
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University, Seoul, 02447, Korea.,Korea Institute for Advanced Study (KIAS), Seoul, 02455, Korea
| | - Miyoung Kim
- Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Korea.
| | - Young-Kyun Kwon
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University, Seoul, 02447, Korea. .,Korea Institute for Advanced Study (KIAS), Seoul, 02455, Korea.
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9
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Massabuau FCP, Rhode SL, Horton MK, O'Hanlon TJ, Kovács A, Zielinski MS, Kappers MJ, Dunin-Borkowski RE, Humphreys CJ, Oliver RA. Dislocations in AlGaN: Core Structure, Atom Segregation, and Optical Properties. Nano Lett 2017; 17:4846-4852. [PMID: 28707893 DOI: 10.1021/acs.nanolett.7b01697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We conducted a comprehensive investigation of dislocations in Al0.46Ga0.54N. Using aberration-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy, the atomic structure and atom distribution at the dislocation core have been examined. We report that the core configuration of dislocations in AlGaN is consistent with that of other materials in the III-Nitride system. However, we observed that the dissociation of mixed-type dislocations is impeded by alloying GaN with AlN, which is confirmed by our experimental observation of Ga and Al atom segregation in the tensile and compressive parts of the dislocations, respectively. Investigation of the optical properties of the dislocations shows that the atom segregation at dislocations has no significant effect on the intensity recorded by cathodoluminescence in the vicinity of the dislocations. These results are in contrast with the case of dislocations in In0.09Ga0.91N where segregation of In and Ga atoms also occurs but results in carrier localization limiting non-radiative recombination at the dislocation. This study therefore sheds light on why InGaN-based devices are generally more resilient to dislocations than their AlGaN-based counterparts.
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Affiliation(s)
- Fabien C-P Massabuau
- Department of Materials Science and Metallurgy, University of Cambridge , Cambridge CB3 0FS, United Kingdom
| | - Sneha L Rhode
- Department of Materials, Imperial College London , London SW7 2AZ, United Kingdom
| | - Matthew K Horton
- Materials Science and Engineering, University of California Berkeley , Berkeley, California 94720, United States
| | - Thomas J O'Hanlon
- Department of Materials Science and Metallurgy, University of Cambridge , Cambridge CB3 0FS, United Kingdom
| | - András Kovács
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH , D-52425 Jülich, Germany
| | | | - Menno J Kappers
- Department of Materials Science and Metallurgy, University of Cambridge , Cambridge CB3 0FS, United Kingdom
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH , D-52425 Jülich, Germany
| | - Colin J Humphreys
- Department of Materials Science and Metallurgy, University of Cambridge , Cambridge CB3 0FS, United Kingdom
| | - Rachel A Oliver
- Department of Materials Science and Metallurgy, University of Cambridge , Cambridge CB3 0FS, United Kingdom
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10
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Yang H, Lozano JG, Pennycook TJ, Jones L, Hirsch PB, Nellist PD. Imaging screw dislocations at atomic resolution by aberration-corrected electron optical sectioning. Nat Commun 2015; 6:7266. [PMID: 26041257 PMCID: PMC4468905 DOI: 10.1038/ncomms8266] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 04/23/2015] [Indexed: 11/10/2022] Open
Abstract
Screw dislocations play an important role in materials' mechanical, electrical and optical properties. However, imaging the atomic displacements in screw dislocations remains challenging. Although advanced electron microscopy techniques have allowed atomic-scale characterization of edge dislocations from the conventional end-on view, for screw dislocations, the atoms are predominantly displaced parallel to the dislocation line, and therefore the screw displacements are parallel to the electron beam and become invisible when viewed end-on. Here we show that screw displacements can be imaged directly with the dislocation lying in a plane transverse to the electron beam by optical sectioning using annular dark field imaging in a scanning transmission electron microscope. Applying this technique to a mixed [a+c] dislocation in GaN allows direct imaging of a screw dissociation with a 1.65-nm dissociation distance, thereby demonstrating a new method for characterizing dislocation core structures.
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Affiliation(s)
- H Yang
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - J G Lozano
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - T J Pennycook
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK.,EPSRC SuperSTEM Facility, STFC Daresbury, WA4 4AD, UK
| | - L Jones
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - P B Hirsch
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK
| | - P D Nellist
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, UK.,EPSRC SuperSTEM Facility, STFC Daresbury, WA4 4AD, UK
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11
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Tang F, Moody MP, Martin TL, Bagot PAJ, Kappers MJ, Oliver RA. Practical Issues for Atom Probe Tomography Analysis of III-Nitride Semiconductor Materials. Microsc Microanal 2015; 21:544-556. [PMID: 25926083 DOI: 10.1017/s1431927615000422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Various practical issues affecting atom probe tomography (APT) analysis of III-nitride semiconductors have been studied as part of an investigation using a c-plane InAlN/GaN heterostructure. Specimen preparation was undertaken using a focused ion beam microscope with a mono-isotopic Ga source. This enabled the unambiguous observation of implantation damage induced by sample preparation. In the reconstructed InAlN layer Ga implantation was demonstrated for the standard "clean-up" voltage (5 kV), but this was significantly reduced by using a lower voltage (e.g., 1 kV). The characteristics of APT data from the desorption maps to the mass spectra and measured chemical compositions were examined within the GaN buffer layer underlying the InAlN layer in both pulsed laser and pulsed voltage modes. The measured Ga content increased monotonically with increasing laser pulse energy and voltage pulse fraction within the examined ranges. The best results were obtained at very low laser energy, with the Ga content close to the expected stoichiometric value for GaN and the associated desorption map showing a clear crystallographic pole structure.
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Affiliation(s)
- Fengzai Tang
- 1Department of Materials Science and Metallurgy,University of Cambridge,27 Charles Babbage Road,Cambridge CB3 0FS,UK
| | - Michael P Moody
- 2Departments of Materials,University of Oxford,Parks Road,Oxford OX1 3PH,UK
| | - Tomas L Martin
- 2Departments of Materials,University of Oxford,Parks Road,Oxford OX1 3PH,UK
| | - Paul A J Bagot
- 2Departments of Materials,University of Oxford,Parks Road,Oxford OX1 3PH,UK
| | - Menno J Kappers
- 1Department of Materials Science and Metallurgy,University of Cambridge,27 Charles Babbage Road,Cambridge CB3 0FS,UK
| | - Rachel A Oliver
- 1Department of Materials Science and Metallurgy,University of Cambridge,27 Charles Babbage Road,Cambridge CB3 0FS,UK
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12
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Horton MK, Rhode S, Sahonta SL, Kappers MJ, Haigh SJ, Pennycook TJ, Humphreys CJ, Dusane RO, Moram MA. Segregation of In to dislocations in InGaN. Nano Lett 2015; 15:923-930. [PMID: 25594363 DOI: 10.1021/nl5036513] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Dislocations are one-dimensional topological defects that occur frequently in functional thin film materials and that are known to degrade the performance of InxGa1-xN-based optoelectronic devices. Here, we show that large local deviations in alloy composition and atomic structure are expected to occur in and around dislocation cores in InxGa(1-x)N alloy thin films. We present energy-dispersive X-ray spectroscopy data supporting this result. The methods presented here are also widely applicable for predicting composition fluctuations associated with strain fields in other inorganic functional material thin films.
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Affiliation(s)
- Matthew K Horton
- Department of Materials, Imperial College London , Exhibition Road, London SW7 2AZ, United Kingdom
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13
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Puchtler TJ, Woolf A, Zhu T, Gachet D, Hu EL, Oliver RA. Effect of Threading Dislocations on the Quality Factor of InGaN/GaN Microdisk Cavities. ACS Photonics 2015; 2:137-143. [PMID: 25839048 PMCID: PMC4372119 DOI: 10.1021/ph500426g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Indexed: 06/04/2023]
Abstract
In spite of the theoretical advantages associated with nitride microcavities, the quality factors of devices with embedded indium gallium nitride (InGaN) or gallium nitride (GaN) optical emitters still remain low. In this work we identify threading dislocations (TDs) as a major limitation to the fabrication of high quality factor devices in the nitrides. We report on the use of cathodoluminescence (CL) to identify individual TD positions within microdisk lasers containing either InGaN quantum wells or quantum dots. Using CL to accurately count the number, and map the position, of dislocations within several individual cavities, we have found a clear correlation between the density of defects in the high-field region of a microdisk and its corresponding quality factor (Q). We discuss possible mechanisms associated with defects, photon scattering, and absorption, which could be responsible for degraded device performance.
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Affiliation(s)
- Tim J. Puchtler
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, U.K.
| | - Alexander Woolf
- School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Tongtong Zhu
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, U.K.
| | - David Gachet
- Attolight AG, EPFL Innovation Park - Bâtiment D, CH-1015 Lausanne, Switzerland
| | - Evelyn L. Hu
- School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Rachel A. Oliver
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, U.K.
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14
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Cao D, Cheng X, Xie Y, Li X, Wang Z, Xia C, Zheng L, Xu D, Shen L, Yu Y. Properties of HfO2/La2O3nanolaminate films grown on an AlGaN/GaN heterostructure by plasma enhanced atomic layer deposition. RSC Adv 2014. [DOI: 10.1039/c4ra06542e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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