Development of novel AlN crystal growth method using Al vapor generated from heated Ga-Al soluiton

• Project/Area Number: 17K19067
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Applied physics and engineering and related fields
• Research Institution: Tohoku University
• Principal Investigator: Adachi Masayoshi 東北大学, 多元物質科学研究所, 助教 (90598913)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2019: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2017: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: 気相成長 / 蒸発 / 窒化アルミニウム / エピタキシャル成長 / Ga-Alフラックス / 結晶成長 / 電子・電気材料

Outline of Final Research Achievements

AlGaN-based LEDs have a wide ultraviolet light emission range between 3.4 and 6.0 eV; therefore, they have potential in many applications such as sterilization, white light illumination, water or air purification equipment. AlN is a promising substrate material for AlGaN-based LEDs. In this study, authors have developed a new AlN vapor phase growth method using evaporation of Al from Ga-Al flux.

Academic Significance and Societal Importance of the Research Achievements

AlNは高温で高い解離圧を示すため，常圧下では融解する前に解離する．そのため，シリコンのように自身の融液から単結晶を作製することが困難であり，その量産技術が確立していない．そこで，本研究課題では，AlN結晶の量産技術となり得る手法の開発を目指した研究を行った．本研究課題の成果を元に，本技術の実用化へ向けた研究を継続し，AlN結晶の量産技術の確立を目指す．

Research Products

• [Journal Article] In‐situ observation of AlN formation from Ni‐Al solution using an electromagnetic levitation technique (2020)
  • Author(s): Adachi Masayoshi、Hamaya Sonoko、Yamagata Yuji、Loach Andrew J.、Fada Justin S.、Wilson Laura G.、French Roger H.、Carter Jennifer L. W.、Fukuyama Hiroyuki
  • Journal Title: Journal of the American Ceramic Society Volume: 103 Issue: 4 Pages: 2389-2398
  • DOI: 10.1111/jace.16960
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Compositiondependence of normal spectral emissivity of liquid Ni-Al alloys measured by electromagnetic levitation technique (2019)
  • Author(s): Masayoshi Adachi, Yuji Yamagata, Makoto Ohtsuka, Hiroyuki Fukuyama
  • Organizer: The 12th Interntional Workshop on Subsecond Thermophysics (IWSSTP-2019)
  • Int'l Joint Research
• [Presentation] AlN Growth Behavior on Ni-Al Liquid Solution (2019)
  • Author(s): M. Adachi, S. Sonoko, A. Kanbara, L.G. Wilson, B.G. Pierce, A.M. Karimi, R.H. French, J.L.W. Carter, H. Fukuyama
  • Organizer: 4th International Workshop on Ultraviolet Materials and Devices (IWUMD4)
  • Int'l Joint Research / Invited
• [Presentation] In-Situ observation of liquid phase epitaxial growth of an AlN layer by optical microscopy (2018)
  • Author(s): Masayoshi Adachi, Keigo Fujiwara, Hidekazu Kobatake, Makoto Ohtsuka, and Hiroyuki Fukuyama
  • Organizer: Twentieth Symposium on Thermophysical Properties
  • Int'l Joint Research
• [Presentation] AlN Crystal Growth Using Vaporized Al from Ga-Al flux with Nitrogen Injection (2017)
  • Author(s): Keigo Takahashi, Masayoshi Adachi, Hiroyuki Fukuyama
  • Organizer: 12th International Conference on Nitride Semiconductors (ICNS-12)
  • Int'l Joint Research
• [Presentation] Ga-Al融液を用いたAlN結晶気相成長法における炉内圧力が結晶成長に及ぼす影響 (2017)
  • Author(s): 高橋慧伍，安達正芳，福山博之
  • Organizer: 日本金属学会