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Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers
In this work, 4H-SiC epilayers are performed on 4° off-axis substrates under low pressure condition by horizontal hot wall chemical vapor deposition (HWCVD) with a standard chemistry of silane-propane-hydrogen, which focuses on the effects of growth pressure on morphology, basal plane dislocations (...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457113/ https://www.ncbi.nlm.nih.gov/pubmed/28773864 http://dx.doi.org/10.3390/ma9090743 |
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author | Hu, Jichao Jia, Renxu Xin, Bin Peng, Bo Wang, Yuehu Zhang, Yuming |
author_facet | Hu, Jichao Jia, Renxu Xin, Bin Peng, Bo Wang, Yuehu Zhang, Yuming |
author_sort | Hu, Jichao |
collection | PubMed |
description | In this work, 4H-SiC epilayers are performed on 4° off-axis substrates under low pressure condition by horizontal hot wall chemical vapor deposition (HWCVD) with a standard chemistry of silane-propane-hydrogen, which focuses on the effects of growth pressure on morphology, basal plane dislocations (BPDs) and crystalline quality. It is found that morphological defects reduce with the decreasing of growth pressure, since the surface diffusion length of absorbed adatoms increases under low growth pressure, which suppresses the nucleation of adatoms on terraces and the formation of morphological defects. However, as the surface diffusion length increases under low growth pressure, the difference of growth velocity at steps is enhanced, which leads to the extension of the steps’ width and the formation of step-bunching. Besides variation of surface diffusion length, the phenomenon described above can be correlated with different dominate modes for the minimization of surface energy at varied growth pressure. Because of the contrary influence of increased C/Si ratio and enhanced step-flow growth on the propagation of BPDs, the dislocation densities of BPDs and threading edge dislocations (TEDs) in epilayers grown at varied pressures remain basically unchanged. The crystalline quality is almost independent of growth pressure based on high resolution X-ray diffraction (HRXRD) measurements. |
format | Online Article Text |
id | pubmed-5457113 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-54571132017-07-28 Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers Hu, Jichao Jia, Renxu Xin, Bin Peng, Bo Wang, Yuehu Zhang, Yuming Materials (Basel) Article In this work, 4H-SiC epilayers are performed on 4° off-axis substrates under low pressure condition by horizontal hot wall chemical vapor deposition (HWCVD) with a standard chemistry of silane-propane-hydrogen, which focuses on the effects of growth pressure on morphology, basal plane dislocations (BPDs) and crystalline quality. It is found that morphological defects reduce with the decreasing of growth pressure, since the surface diffusion length of absorbed adatoms increases under low growth pressure, which suppresses the nucleation of adatoms on terraces and the formation of morphological defects. However, as the surface diffusion length increases under low growth pressure, the difference of growth velocity at steps is enhanced, which leads to the extension of the steps’ width and the formation of step-bunching. Besides variation of surface diffusion length, the phenomenon described above can be correlated with different dominate modes for the minimization of surface energy at varied growth pressure. Because of the contrary influence of increased C/Si ratio and enhanced step-flow growth on the propagation of BPDs, the dislocation densities of BPDs and threading edge dislocations (TEDs) in epilayers grown at varied pressures remain basically unchanged. The crystalline quality is almost independent of growth pressure based on high resolution X-ray diffraction (HRXRD) measurements. MDPI 2016-08-31 /pmc/articles/PMC5457113/ /pubmed/28773864 http://dx.doi.org/10.3390/ma9090743 Text en © 2016 by the authors; Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Hu, Jichao Jia, Renxu Xin, Bin Peng, Bo Wang, Yuehu Zhang, Yuming Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers |
title | Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers |
title_full | Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers |
title_fullStr | Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers |
title_full_unstemmed | Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers |
title_short | Effect of Low Pressure on Surface Roughness and Morphological Defects of 4H-SiC Epitaxial Layers |
title_sort | effect of low pressure on surface roughness and morphological defects of 4h-sic epitaxial layers |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457113/ https://www.ncbi.nlm.nih.gov/pubmed/28773864 http://dx.doi.org/10.3390/ma9090743 |
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