Low Dislocation of Semi-Polar AlN Virtual Substrates by Multi-Step High Temperature Growth Method and Deep UV Light Emitting Diodes

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05297
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 30010:Crystal engineering-related
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Jo Masafumi 国立研究開発法人理化学研究所, 開拓研究本部, 専任研究員 (20400020)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: AlGaN / 半極性面 / PL / EL

Outline of Final Research Achievements

We have succeeded in reducing dislocation density in (11-22)AlN virtual substrates by combining a multi-step high-temperature growth method and external annealing treatment, resulting in a two-digit reduction in defect density. (11-22)AlGaN quantum wells were fabricated on high-quality AlN virtual substrates, and clear UVC emission was obtained at room temperature. Furthermore, current injection luminescence at UVB was also achieved. The (10-13) surface was also successfully improved to high quality, and quantum well luminescence in the UVB region at room temperature was achieved for both photoexcitation and current injection.

Free Research Field

半導体量子構造

Academic Significance and Societal Importance of the Research Achievements

深紫外光は殺菌をはじめとした幅広い用途を持つため、小型で堅牢、波長可変といった特性を持つLEDを用いた深紫外光源が実現できれば社会の様々な場面で役に立つことが期待される。深紫外LEDの高性能化アプローチの1つとして、半極性面を用いた結晶成長が注目されているが、従来は結晶性が低く満足な特性は得られていなかった。本研究では成長方法を工夫することにより結晶の高品質化を実現し、深紫外波長域において半極性面デバイスで初の室温動作を達成した。本結果は今後の半極性面デバイス実用化へ大きく前進したものといえる。