Realization of n-type AlN by clarifying the mechanism of point defect formation in bulk AlN crystal

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03555
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Crystal engineering
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Kumagai Yoshinao 東京農工大学, 工学(系)研究科(研究院), 卓越教授 (20313306)
• Co-Investigator(Kenkyū-buntansha): 村上 尚 東京農工大学, 工学(系)研究科(研究院), 准教授 (90401455) ; 富樫 理恵 東京農工大学, 工学(系)研究科(研究院), 助教 (50444112)
• Research Collaborator: SITAR Zlatko ; KINOSHITA Toru ; TUOMISTO Filip
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 窒化アルミニウム / 点欠陥 / n形導電性 / 不純物 / ドーピング / HVPE法 / ショットキーバリアダイオード

Outline of Final Research Achievements

Realization of AlN substrates with n-type conductivity was investigated by high-speed growth of thick AlN layers using hydride vapor phase epitaxy (HVPE) on low-dislocation-density bulk AlN substrates prepared by physical vapor transport. Mechanism of unintentionally accumulated high concentration of Si impurity on the HVPE-AlN surface was clarified, which made it possible to eliminate the Si accumulation and investigate intentional Si doping for AlN. Control of Si concentration in AlN could be achieved by using silicon tetrachloride as a doping gas. Bulk AlN substrates with n-type conductivity were successfully prepared by the intentional Si doping. World first vertical Schottky barrier diodes fabricated using the n-type AlN substrates showed high rectification and high reverse breakdown voltage.

Free Research Field

結晶成長