Study on nitrogen-polar InGaAs-channel high electron mobility transistors

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04341
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Electron device/Electronic equipment
• Research Institution: Tohoku University
• Principal Investigator: Suemitsu Tetsuya 東北大学, 国際集積エレクトロニクス研究開発センター, 教授 (90447186)
• Co-Investigator(Kenkyū-buntansha): 松岡 隆志 東北大学, 金属材料研究所, 教授 (40393730)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: トランジスタ / 窒化物半導体 / マイクロ波・ミリ波

Outline of Final Research Achievements

Growth and fabrication of (In)GaN/AlGaN high electron mobility transistors (HEMTs) using N-polar GaN materials were studied. Flat surface and two-dimensional electron gas were realized by substrates with an off-cut angle of as small as 0.8 degree. This enables to achieve isotropic electrical characteristics in N-polar GaN HEMTs. To reduce the deep levels at the gate insulator interface, reverse bias annealing was carried out and the reduction of the interface trap density was confirmed in N-polar HEMTs as it was reported for gallium-polar HEMTs.

Free Research Field

半導体デバイス工学

Academic Significance and Societal Importance of the Research Achievements

窒素極性窒化物半導体材料を用いた高電子移動度トランジスタ（HEMT）を国内では初めて実現した。また、世界的にも、先行研究と比較してオフ角が小さい基板上に平坦なエピタキシャル結晶を成長させることに成功し、これまで確認されていたウエハ面内での素子特性の異方性を抑えることが出来た。また、ゲート絶縁膜界面の品質向上に逆バイアスアニール処理が効果的であることを窒素極性HEMTで初めて確認した。