Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers
The high crystal quality and low dislocation densities of aluminum nitride (AlN) grown on flat and nano-patterned sapphire substrate that are synthesized by the metal-organic chemical vapor deposition (MOCVD) method are essential for the realization of high-efficiency deep ultraviolet light-emitting...
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MDPI AG
2022-11-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/12/22/3937 |
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| author | Wenwang Wei Yi Peng Yanlian Yang Kai Xiao Mudassar Maraj Jia Yang Yukun Wang Wenhong Sun |
| author_facet | Wenwang Wei Yi Peng Yanlian Yang Kai Xiao Mudassar Maraj Jia Yang Yukun Wang Wenhong Sun |
| author_sort | Wenwang Wei |
| collection | DOAJ |
| description | The high crystal quality and low dislocation densities of aluminum nitride (AlN) grown on flat and nano-patterned sapphire substrate that are synthesized by the metal-organic chemical vapor deposition (MOCVD) method are essential for the realization of high-efficiency deep ultraviolet light-emitting diodes. The micro-strains of 0.18 × 10<sup>−3</sup> cm<sup>−2</sup> for flat substrate AlN and 0.11 × 10<sup>−3</sup> cm<sup>−2</sup> for nano-patterned substrate AlN are obtained by X-ray diffractometer (XRD). The screw and edge dislocation densities of samples are determined by XRD and transmission electron microscope (TEM), and the results indicate that the nano-patterned substrates are effective in reducing the threading dislocation density. The mechanism of the variation of the threading dislocation in AlN films grown on flat and nano-patterned substrates is investigated comparatively. The etch pit density (EPD) determined by preferential chemical etching is about 1.04 × 10<sup>8</sup> cm<sup>−2</sup> for AlN grown on a nano-patterned substrate, which is slightly smaller than the results obtained by XRD and TEM investigation. Three types of etch pits with different sizes are all revealed on the AlN surface using the hot KOH etching method. |
| first_indexed | 2024-03-09T18:06:12Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-09T18:06:12Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-9a1e86f62fcb4cae9ff0b558731df7182023-11-24T09:26:59ZengMDPI AGNanomaterials2079-49912022-11-011222393710.3390/nano12223937Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN EpilayersWenwang Wei0Yi Peng1Yanlian Yang2Kai Xiao3Mudassar Maraj4Jia Yang5Yukun Wang6Wenhong Sun7Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaResearch Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaResearch Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaResearch Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaResearch Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaResearch Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaResearch Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaResearch Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, ChinaThe high crystal quality and low dislocation densities of aluminum nitride (AlN) grown on flat and nano-patterned sapphire substrate that are synthesized by the metal-organic chemical vapor deposition (MOCVD) method are essential for the realization of high-efficiency deep ultraviolet light-emitting diodes. The micro-strains of 0.18 × 10<sup>−3</sup> cm<sup>−2</sup> for flat substrate AlN and 0.11 × 10<sup>−3</sup> cm<sup>−2</sup> for nano-patterned substrate AlN are obtained by X-ray diffractometer (XRD). The screw and edge dislocation densities of samples are determined by XRD and transmission electron microscope (TEM), and the results indicate that the nano-patterned substrates are effective in reducing the threading dislocation density. The mechanism of the variation of the threading dislocation in AlN films grown on flat and nano-patterned substrates is investigated comparatively. The etch pit density (EPD) determined by preferential chemical etching is about 1.04 × 10<sup>8</sup> cm<sup>−2</sup> for AlN grown on a nano-patterned substrate, which is slightly smaller than the results obtained by XRD and TEM investigation. Three types of etch pits with different sizes are all revealed on the AlN surface using the hot KOH etching method.https://www.mdpi.com/2079-4991/12/22/3937nano-patternedAlNdislocation densitiesetch pit density |
| spellingShingle | Wenwang Wei Yi Peng Yanlian Yang Kai Xiao Mudassar Maraj Jia Yang Yukun Wang Wenhong Sun Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers Nanomaterials nano-patterned AlN dislocation densities etch pit density |
| title | Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers |
| title_full | Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers |
| title_fullStr | Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers |
| title_full_unstemmed | Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers |
| title_short | Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers |
| title_sort | study of defects and nano patterned substrate regulation mechanism in aln epilayers |
| topic | nano-patterned AlN dislocation densities etch pit density |
| url | https://www.mdpi.com/2079-4991/12/22/3937 |
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