Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-Wafers
The integration of thick homoepitaxial layers on silicon carbide (SiC) substrates is critical for enabling high-voltage power devices, yet it remains challenged by substrate surface quality and wafer geometry evolution. This study investigates the relationship between substrate preparation—particula...
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2025-06-01
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| author | Chi-Hsiang Hsieh Chiao-Yang Cheng Yi-Kai Hsiao Zi-Hao Wang Chang-Ching Tu Chao-Chang Arthur Chen Po-Tsung Lee Hao-Chung Kuo |
| author_facet | Chi-Hsiang Hsieh Chiao-Yang Cheng Yi-Kai Hsiao Zi-Hao Wang Chang-Ching Tu Chao-Chang Arthur Chen Po-Tsung Lee Hao-Chung Kuo |
| author_sort | Chi-Hsiang Hsieh |
| collection | DOAJ |
| description | The integration of thick homoepitaxial layers on silicon carbide (SiC) substrates is critical for enabling high-voltage power devices, yet it remains challenged by substrate surface quality and wafer geometry evolution. This study investigates the relationship between substrate preparation—particularly chemical mechanical planarization (CMP)—and the impact on wafer bow, total thickness variation (TTV), local thickness variation (LTV), and defect propagation during epitaxial growth. Seven 150 mm, 4° off-axis, prime-grade 4H-SiC substrates from a single ingot were processed under high-volume manufacturing (HVM) conditions and grown with epitaxial layers ranging from 12 μm to 100 μm. Metrology revealed a strong correlation between increasing epitaxial thickness and geometric deformation, especially beyond 31 μm. Despite initial surface scratches from CMP, hydrogen etching and buffer layer deposition significantly mitigated scratch propagation, as confirmed through defect mapping and SEM/FIB analysis. These findings provide a deeper understanding of the substrate-to-epitaxy integration process and offer pathways to improve manufacturability and yield in thick-epilayer SiC device fabrication. |
| format | Article |
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| institution | Kabale University |
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| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
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| series | Micromachines |
| spelling | doaj-art-516f00e5c97042ff85f695c436e73cfd2025-08-20T03:29:40ZengMDPI AGMicromachines2072-666X2025-06-0116671010.3390/mi16060710Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-WafersChi-Hsiang Hsieh0Chiao-Yang Cheng1Yi-Kai Hsiao2Zi-Hao Wang3Chang-Ching Tu4Chao-Chang Arthur Chen5Po-Tsung Lee6Hao-Chung Kuo7Department of Photonics, Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 300093, TaiwanWafer Technology Division, HuaHsu Silicon Materials Corporation, Taichung 407019, TaiwanSemiconductor Research Center, Hon Hai Research Institute, Taipei 114699, TaiwanAcademy of Innovative Semiconductor and Sustainable Manufacturing, National Cheng Kung University, Tainan 701401, TaiwanSemiconductor Research Center, Hon Hai Research Institute, Taipei 114699, TaiwanDepartment of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei 106335, TaiwanDepartment of Photonics, Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 300093, TaiwanDepartment of Photonics, Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 300093, TaiwanThe integration of thick homoepitaxial layers on silicon carbide (SiC) substrates is critical for enabling high-voltage power devices, yet it remains challenged by substrate surface quality and wafer geometry evolution. This study investigates the relationship between substrate preparation—particularly chemical mechanical planarization (CMP)—and the impact on wafer bow, total thickness variation (TTV), local thickness variation (LTV), and defect propagation during epitaxial growth. Seven 150 mm, 4° off-axis, prime-grade 4H-SiC substrates from a single ingot were processed under high-volume manufacturing (HVM) conditions and grown with epitaxial layers ranging from 12 μm to 100 μm. Metrology revealed a strong correlation between increasing epitaxial thickness and geometric deformation, especially beyond 31 μm. Despite initial surface scratches from CMP, hydrogen etching and buffer layer deposition significantly mitigated scratch propagation, as confirmed through defect mapping and SEM/FIB analysis. These findings provide a deeper understanding of the substrate-to-epitaxy integration process and offer pathways to improve manufacturability and yield in thick-epilayer SiC device fabrication.https://www.mdpi.com/2072-666X/16/6/710SiC thick epitaxialSiC defect propagationSiC wafer geometry |
| spellingShingle | Chi-Hsiang Hsieh Chiao-Yang Cheng Yi-Kai Hsiao Zi-Hao Wang Chang-Ching Tu Chao-Chang Arthur Chen Po-Tsung Lee Hao-Chung Kuo Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-Wafers Micromachines SiC thick epitaxial SiC defect propagation SiC wafer geometry |
| title | Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-Wafers |
| title_full | Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-Wafers |
| title_fullStr | Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-Wafers |
| title_full_unstemmed | Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-Wafers |
| title_short | Influence of Homoepitaxial Layer Thickness on Flatness and Chemical Mechanical Planarization Induced Scratches of 4H-Silicon Carbide Epi-Wafers |
| title_sort | influence of homoepitaxial layer thickness on flatness and chemical mechanical planarization induced scratches of 4h silicon carbide epi wafers |
| topic | SiC thick epitaxial SiC defect propagation SiC wafer geometry |
| url | https://www.mdpi.com/2072-666X/16/6/710 |
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