ワットクラス超高出力紫外レーザダイオードの実現

2007 Fiscal Year Annual Research Report

• Project Area: Optoelectronics Frontier by Nitride Semiconductor -Ultimate Utilization of Nitride Semiconductor Material Potential-
• Project/Area Number: 18069011
• Research Institution: Meijo University
• Principal Investigator: 天野 浩 Meijo University, 理工学部, 教授 (60202694)
• Co-Investigator(Kenkyū-buntansha): 上山 智 名城大学, 理工学部, 教授 (10340291) ; 岩谷 素顕 名城大学, 理工学部, 准教授 (40367735)
• Keywords: 紫外半導体レーザ / AIN / GaN / AlGaN / 紫外発光ダイオード / デバイスシミュレータ / 発光効率 / 低転位化

Research Abstract

本研究課題は、科学研究費補助金特定領域研究「窒化物光半導体のフロンティア-材料潜在能力の極限発現-」の計画研究として、窒化物光半導体によるワットクラスの半導体レーザ(LD)の実現を目指し研究を推進している。本研究課題のターゲットである紫外半導体レーザは、医療分野や精密加工などの工学分野において実用化が嘱望されている。このような目標を元に、平成19年度に推進した研究の概要ならびに成果を列記し概略について説明する。
1.AIN上に作製したAIGaN層の高品質化…平成18年度までに基盤技術を確立した、高品質AIN上にAlGaNを作製する技術の確立をはかった。特に、AlGaNの格子緩和/結晶性劣化ならびにその回復過程、さらにはAlGaNの組成依存性について詳細な解析を進めた。さらにAINおよびAlGaNに溝加工を施すことによって、AlGaNの結晶の高品質化を進めた。以上の検討によって、半導体レーザに必要な低転位・クラックフリーな高品質なAlGaNを実現した。
2.紫外LEDの高効率化…活性層の内部量子効率の向上、電流注入効率の向上を目指し、デバイスシミュレータ、デバイス試作および評価を進め、外部量子効率6.7%の350nm帯紫外LEDという世界最高の特性を実現した。
3.紫外LDの特性改善の検討…高性能紫外LDを実現するために必須である、AIN上に作製した高品質AlGaN上に356nmの紫外半導体レーザを試作し、室温での電流注入による発振を確認した。また電流注入による素子特性の評価を進め、ワットクラスレーザに必要な課題を明確化した。
上記の成果は、研究実施計画を遵守し進められており、ほぼ目標を達成している。今後は現状の問題点を整理し、最終目標を達成するのは当然として、紫外LEDや紫外LDの応用分野の開拓など、新機軸・新産業の構築を推進していく予定である。

Research Products

• [Journal Article] Annihiation mechanism of threading dislocations in AIN grown by growth form modification method using V/III ratio (2007)
  • Author(s): M. Imura, N. Fujimoto, N. Okada, K. Balakrishnan, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, T. Noro, T. Takagi and A. Bando
  • Journal Title: Journal of Crystal Growth 400 Pages: 136-140
  • Peer Reviewed
• [Journal Article] Epitaxial lateral overgrowth of a-AlN layer on patterned a-AlN template by HT-MOVPE (2007)
  • Author(s): N. Okada, N. Kato, S. Sato, T. Sumii, N. Fujimoto, M. Imura, K. Balak rishnan, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, T. Takagi, T. Noro and A. Bandoh
  • Journal Title: Journal of Crystal Growth 400 Pages: 141-144
  • Peer Reviewed
• [Journal Article] Influence of High Temperature in the Growth of Low Dislocation Content AIN Bridge Layers on Patterned 6H-SiC Substrates by Metalorganic Vapor Phase Epitaxy (2007)
  • Author(s): K. Balakrishnan, A. Bandoh, M. Iwaya, S. Kamiyama, H. Amano and I. Akasaki
  • Journal Title: Japanese Journal of Applied Physics 46 Pages: L307-L310
  • Peer Reviewed
• [Journal Article] Dislocations in AlN Epilayers Grown on Sapphire Substrate by High-Temperature Metal-Organic Vapor Phase Epitaxy (2007)
  • Author(s): M. Imura, K. Nakano, N. Fujimoto, N. Okada, K. Balakrishnan, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, T. Noro, T. Takagi and A. Bandoh
  • Journal Title: Japanese Journal of Applied Physics 46 Pages: 1458-1462
  • Peer Reviewed
• [Journal Article] Microstructure of a-plane AlN grown on r-plane sapphire and on patterned AlN templates by metalorganic vapor phase epitaxy (2007)
  • Author(s): N. Okada, M. Imura, T. Nagai, K. Balakrishnan, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, H. Maruyama, T. Noro, T. Takagi, A. Bandoh
  • Journal Title: physica status solidi(c) 4 Pages: 2528-2531
  • Peer Reviewed
• [Journal Article] Mg-doped high-quality Al_xGa_<1-x>N(x=0-1)grown by high-temperature metal-organic vapor phase epitaxy (2007)
  • Author(s): M. Imura, N. Kato, N. Okada, K. Balakrishnan, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, T. Noro, T. Takagi, A. Bandoh
  • Journal Title: physica status solidi(c) 4 Pages: 2502-2505
  • Peer Reviewed
• [Journal Article] Void assisted dislocation reduction in AlN and AlGaN by high temperature MOVPE (2007)
  • Author(s): K. Balakrishnan, K. Iida, A. Bandoh, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki
  • Journal Title: physica status solidi(c) 4 Pages: 2272-2276
  • Peer Reviewed
• [Journal Article] High-efficiency AlGaN based UV emitters grown on high-crystalline-quality AlGaN using grooved AlN layer on sapphire substrate (2007)
  • Author(s): K. Iida, H. Watanabe, K. Takeda, T. Nagai, T. Sumii, K. Nagamatsu, T. Kawashima, K. Balakrishnan, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, A. Bandoh
  • Journal Title: physica status solidi(a) 204 Pages: 1848-1852
  • Peer Reviewed
• [Journal Article] Optical observation of discrete well width fluctuations in wide band gap III-nitride quantum wells (2007)
  • Author(s): Optical observation of discrete well width fluctuations in wide band gap III-nitride quantum wells
  • Journal Title: physica status solidi(b) 244 Pages: 1727-1734
  • Peer Reviewed
• [Journal Article] Optical properties of GaN/AlGaN QW nanostructures with different well and barrier widths (2007)
  • Author(s): M Esmaeili, M Sabooni, H Haratizadeh, P P Paskov, B Monemar, P O Holz, S Kamiyama and M Iwaya
  • Journal Title: J. Phys.: Condens. Matter 19 Pages: 356218
  • Peer Reviewed
• [Presentation] 高温MOVPEを用いたAlN周期溝上AlGaN中の転位密度のAlNモル分率依存性 (2008)
  • Author(s): 浅井俊晶、住井隆文、加藤尚文、佐藤周夜、森 俊晶、岩谷素顕、上山 智、天野 浩、赤崎 勇
  • Organizer: 2008年春季 第55回応用物理学関係連合講演会
  • Place of Presentation: 日本大学(船橋校舎)
  • Year and Date: 20080327-20080330
• [Presentation] AlGaN中のMgの活性化エネルギー (2008)
  • Author(s): 永松謙太郎、岡田成仁、井村将隆、岩谷素顕、上山 智、天野 浩、赤崎 勇
  • Organizer: 2008年春季 第55回応用物理学関係連合講演会
  • Place of Presentation: 日本大学(船橋校舎)
  • Year and Date: 20080327-20080330
• [Presentation] ELOを用いた高温MOVPE成長AlN/サファイア基板上の高効率UV LED (2008)
  • Author(s): 都築宏俊、森 史明、市川友紀、竹田健一郎、渡邊浩崇、飯田一喜、岩谷素顕、上山 智、天野 浩、赤崎 勇、坂東 章
  • Organizer: 2008年春季 第55回応用物理学関係連合講演会
  • Place of Presentation: 日本大学(船橋校舎)
  • Year and Date: 20080327-20080330
• [Presentation] Nitride-Based UV Lasers (2007)
  • Author(s): H. Amano, N. Kato, N. Okada, T. K awashima, K. Iida, K. Nagamatsu, M. Imura, K. Balakrishnan, M. Iwaya, S. Kamiyama and I. Akasaki
  • Organizer: The 20th Annual Meeting of the IEEE Lasers & Electro-Optics Society (LEOS 2007)
  • Place of Presentation: Florida, USA
  • Year and Date: 20071021-20071025
• [Presentation] Microstructure of Threading Dislocations Caused by Grain Boundaries in AlN on Sapphire Substrate (2007)
  • Author(s): M. Imura, H. Sugimura, N. Okada, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, T. Noro, T. Takagi, A. Bandoh
  • Organizer: The 7th International Conference of Nitride Semi conductors
  • Place of Presentation: Las Vegas, Nevada, USA
  • Year and Date: 20070916-20070921
• [Presentation] Extremely Low Dislocation Content AlN Bridge Layers on Patterned 6H-SiC Substrates by High Temperature MOVPE (2007)
  • Author(s): B. Krishnan, H. Sugimura, A. Band oh, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki
  • Organizer: The 7th International Conference of Nitride Semi conductors
  • Place of Presentation: Las Vegas, Nevada, USA
  • Year and Date: 20070916-20070921
• [Presentation] Critical Issue in Growing High Quality Thick AlGaN by High-Temperature MOVPE (2007)
  • Author(s): N. Kato, T. Sumii, S. Sato, H. Sugimura, N. Okada, M. Imura, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, H. Maruyama, T. Takagi, A. B andoh
  • Organizer: The 7th International Conference of Nitride Semiconductors
  • Place of Presentation: Las Vegas, Nevada, USA
  • Year and Date: 20070916-20070921
• [Presentation] Internal Quantum Efficiency of Al_xGa_<1-x>N (0<x<1) on AlN Template (2007)
  • Author(s): N. Okada, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, H. Maruyama, T. Takagi, A. Bando, H. Murotani, Y. Yamada
  • Organizer: The 7th International Conference of Nitride Semiconductors
  • Place of Presentation: Las Vegas, Nevada, USA
  • Year and Date: 20070916-20070921
• [Presentation] Stimulated Emission from Nonpolar and Polar AlN (2007)
  • Author(s): N. Okada, K. Nagamatsu, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, H. Maruyama, T. Takagi, A. Bando, H. Murotani, Y. Yamada
  • Organizer: The 7th International Conference of Nitride Semiconductors
  • Place of Presentation: Las Vegas, Nevada, USA
  • Year and Date: 20070916-20070921
• [Presentation] UV Emitters Grown on High Crystalline Quality AlGaN on Sapphire (2007)
  • Author(s): K. Iida, F. Mori, H. Watanabe, K. Takeda, K. Nagamatsu, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, H. Maruyama. T. Takagi. A. Bandoh
  • Organizer: The 7th International Conference of Nitride Semiconductors
  • Place of Presentation: Las Vegas, Nevada, USA
  • Year and Date: 20070916-20070921
• [Presentation] Effect of sapphire mis-orientation on the growth of AlN by high temperature MOVPE (2007)
  • Author(s): K. Nagamatsu, N. Okada, N. Kato, T. Sumii, A. Bando, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki
  • Organizer: The 7th International Conference of Nitride Semiconductors
  • Place of Presentation: Las Vegas, Nevada, USA
  • Year and Date: 20070916-20070921
• [Presentation] 紫外発光素子への期待とIII族窒化物半導体を用いた紫外発光素子の高性能化 (2007)
  • Author(s): 天野 浩, 岩谷素顕, 上山 智, 赤崎 勇
  • Organizer: 第68回応用物理学会学術講演会
  • Place of Presentation: 北海道工業大学
  • Year and Date: 20070904-20070908
• [Presentation] Epitaxial lateral overgrowth of low dislocation density AlN by high temperature MOVPE and fabrication of UV optoelectronics devices (2007)
  • Author(s): K. Nagamatsu, N. Okada, F. Mori, K. Iida, M. Imura, K. Balakrishnan, A. Bandoh, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki
  • Organizer: The 13th Conference on Vapor Growth and Epitaxy
  • Place of Presentation: Salt Lake City, Utah, USA
  • Year and Date: 20070812-20070817
• [Presentation] High temperature MOVPE growth-a novel approach to grow high quality AlN layers (2007)
  • Author(s): B. Krishnan, M. Imura, S. Satoh, H. Sugimura, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki
  • Organizer: The 13th Conference on Vapor Growth and Epitaxy
  • Place of Presentation: Salt Lake City, Utah, USA
  • Year and Date: 20070812-20070817
• [Presentation] Microstructure of AlN grown on SiC by high-temperature metalorganic vapor phase epitaxy and epitaxial lateral overgrowth (2007)
  • Author(s): M. Imura, N. Okada, B. Krishnan, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, T. Noro, T. Takagi, A. Bandoh
  • Organizer: The 13th Conference on Vapor Growth and Epitaxy
  • Place of Presentation: Salt Lake City, Utah, USA
  • Year and Date: 20070812-20070817
• [Presentation] High temperature metalorganic vapor phase epitaxial growth of AlN and AlGaN for fabrication of high performance UV/DUV emitters (2007)
  • Author(s): K. Balakrishnan, Kazuyoshi Iida, H. Watanabe, H. Amano, M. Iwaya, I. Akasaki
  • Organizer: 17th International Vacuum Congress(IVC-17),
  • Place of Presentation: Stockholm, Sweden
  • Year and Date: 20070702-20070706