| Project/Area Number |
22K20410
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| Research Category |
Grant-in-Aid for Research Activity Start-up
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| Allocation Type | Multi-year Fund |
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| Review Section |
0301:Mechanics of materials, production engineering, design engineering, fluid engineering, thermal engineering, mechanical dynamics, robotics, aerospace engineering, marine and maritime engineering, and related fields
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| Research Institution | Osaka University |
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Principal Investigator |
SUN RONGYAN 大阪大学, 大学院工学研究科, 助教 (50963451)
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| Project Period (FY) |
2022-08-31 – 2024-03-31
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| Project Status |
Completed (Fiscal Year 2023)
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| Budget Amount *help |
¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2023: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2022: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Keywords | プラズマ援用研磨 / 窒化ガリウム（GaN） |
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| Outline of Research at the Start |
本研究では、GaN基板に対するスラリーを用いない革新的な高能率無歪研磨を実現できる「プラズマ援用研磨プロセス」を実現するとともにその学理を探究する。
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| Outline of Final Research Achievements |
To reduce the processing cost of GaN wafers and improve processing quality and efficiency, vacuum PAP (Plasma-Assisted Polishing) process was proposed. The plasma generation conditions such as gas species, chamber pressure, reaction gas concentration, and power density to enhance the surface modification rate, which is limiting the PAP polishing rate, were optimized. Using the optimal plasma modification conditions, vacuum PAP experiments were conducted on GaN wafers. Before PAP, the GaN wafers were polished by CMP (Chemical Mechanical Polishing), but numerous etch pits were present in the crystal defect regions due to the alkaline components in the slurry. In contrast, after 1 hour of PAP, a pit-free GaN surface with a surface roughness of Sa 0.2 nm was obtained.
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| Academic Significance and Societal Importance of the Research Achievements |
GaNは高硬度ゆえに粗加工にはダイヤモンド工具を用いた機械加工が適用され、最終仕上げにはスラリーと呼ばれるアルカリ等の薬液と砥粒を含む懸濁液を用いたCMPプロセスが一般的に用いられる。しかし、材料の表面欠陥がアルカリ成分によって浸食されてエッチピットが形成されるために表面粗さが悪化する、凝集による砥粒の粗大化によりスクラッチが形成される、スラリーの購入コストと環境負荷が大きい等、多数の問題点を有している。本研究では、スラリーを用いない完全ドライな減圧プラズマ援用研磨法の開発により、GaNウエハの加工コストの低減とGaNデバイスの社会実装に貢献できる。
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