Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrate

Diamond has the highest thermal conductivity among all materials and can be applied to overcome the heat dissipation problem in radio frequency devices based on the heterojunction of gallium nitride (GaN) and 4H silicon carbide (4H-SiC). However, growing high-quality diamond films on 4H-SiC substrat...

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Main Authors: Hanchang Hu, Yuhao Zheng, Pan Deng, Tianqi Deng, Deren Yang, Xiaodong Pi
Format: Article
Language:English
Published: Taylor & Francis Group 2025-12-01
Series:Functional Diamond
Subjects:
Online Access:http://dx.doi.org/10.1080/26941112.2025.2529858
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author Hanchang Hu
Yuhao Zheng
Pan Deng
Tianqi Deng
Deren Yang
Xiaodong Pi
author_facet Hanchang Hu
Yuhao Zheng
Pan Deng
Tianqi Deng
Deren Yang
Xiaodong Pi
author_sort Hanchang Hu
collection DOAJ
description Diamond has the highest thermal conductivity among all materials and can be applied to overcome the heat dissipation problem in radio frequency devices based on the heterojunction of gallium nitride (GaN) and 4H silicon carbide (4H-SiC). However, growing high-quality diamond films on 4H-SiC substrates is quite difficult due to the very low nucleation density of diamond on their surfaces. In this study, the thermodynamic models of diamond nucleation on 4H-SiC substrates were carefully analyzed to investigate the effect of different surface states on diamond nucleation. The results indicated that although a 4H-SiC substrate with a smooth surface can significantly reduce the formation energy of diamond nucleation, it remains challenging for diamond to nucleate on the substrate. Fortunately, increasing the surface roughness can further decrease the formation energy of diamond nucleation and significantly increase the nucleation density on the 4H-SiC substrate, enabling the formation of a continuous high-quality film. Additionally, the rough surface of 4H-SiC substrates lapped by abrasives with small particle size contained numerous nanoscale defects and dense scratches, which serve as active sites for diamond nucleation. The smaller the particle size of the abrasives, the higher the nucleation density of diamond, which is also beneficial for the epitaxial growth of diamond on 4H-SiC substrates. Finally, crack-free diamond films on 4H-SiC substrates were successfully fabricated using an MPCVD system, and their properties were characterized by scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD), respectively.
format Article
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institution Kabale University
issn 2694-1120
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publishDate 2025-12-01
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series Functional Diamond
spelling doaj-art-2272fc77af5341c2bcae80e99b084e0b2025-08-20T03:27:48ZengTaylor & Francis GroupFunctional Diamond2694-11202025-12-015110.1080/26941112.2025.25298582529858Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrateHanchang Hu0Yuhao Zheng1Pan Deng2Tianqi Deng3Deren Yang4Xiaodong Pi5State Key Laboratory of Silicon and Advanced Semiconductor Materials & School of Materials Science and Engineering, Zhejiang UniversityState Key Laboratory of Silicon and Advanced Semiconductor Materials & School of Materials Science and Engineering, Zhejiang UniversityState Key Laboratory of Silicon and Advanced Semiconductor Materials & School of Materials Science and Engineering, Zhejiang UniversityState Key Laboratory of Silicon and Advanced Semiconductor Materials & School of Materials Science and Engineering, Zhejiang UniversityState Key Laboratory of Silicon and Advanced Semiconductor Materials & School of Materials Science and Engineering, Zhejiang UniversityState Key Laboratory of Silicon and Advanced Semiconductor Materials & School of Materials Science and Engineering, Zhejiang UniversityDiamond has the highest thermal conductivity among all materials and can be applied to overcome the heat dissipation problem in radio frequency devices based on the heterojunction of gallium nitride (GaN) and 4H silicon carbide (4H-SiC). However, growing high-quality diamond films on 4H-SiC substrates is quite difficult due to the very low nucleation density of diamond on their surfaces. In this study, the thermodynamic models of diamond nucleation on 4H-SiC substrates were carefully analyzed to investigate the effect of different surface states on diamond nucleation. The results indicated that although a 4H-SiC substrate with a smooth surface can significantly reduce the formation energy of diamond nucleation, it remains challenging for diamond to nucleate on the substrate. Fortunately, increasing the surface roughness can further decrease the formation energy of diamond nucleation and significantly increase the nucleation density on the 4H-SiC substrate, enabling the formation of a continuous high-quality film. Additionally, the rough surface of 4H-SiC substrates lapped by abrasives with small particle size contained numerous nanoscale defects and dense scratches, which serve as active sites for diamond nucleation. The smaller the particle size of the abrasives, the higher the nucleation density of diamond, which is also beneficial for the epitaxial growth of diamond on 4H-SiC substrates. Finally, crack-free diamond films on 4H-SiC substrates were successfully fabricated using an MPCVD system, and their properties were characterized by scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD), respectively.http://dx.doi.org/10.1080/26941112.2025.2529858diamond4h-sicthermodynamicsnucleationthermal
spellingShingle Hanchang Hu
Yuhao Zheng
Pan Deng
Tianqi Deng
Deren Yang
Xiaodong Pi
Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrate
Functional Diamond
diamond
4h-sic
thermodynamics
nucleation
thermal
title Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrate
title_full Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrate
title_fullStr Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrate
title_full_unstemmed Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrate
title_short Effect of surface roughness on the nucleation of diamond on a 4H-SiC substrate
title_sort effect of surface roughness on the nucleation of diamond on a 4h sic substrate
topic diamond
4h-sic
thermodynamics
nucleation
thermal
url http://dx.doi.org/10.1080/26941112.2025.2529858
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