Hydrogen Terminated Diamond MOSFETs by Hydrogen Containing Aluminum Oxide Thin Film

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K13804
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Kindai University (2021); Nara Institute of Science and Technology (2018-2020)
• Principal Investigator: Fujii Mami 近畿大学, 理工学部, 准教授 (30731913)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: ダイヤモンド / 界面 / 欠陥 / トランジスタ

Outline of Final Research Achievements

In this study, we focused on the modification of the interface state between diamond and insulating film, and investigated the effect of insulating film deposition conditions on the interface defect state of transistor devices.
Aluminum oxide thin films were deposited as insulating films by atomic layer deposition, using trimethylaluminum (TMA) and dimethylaluminum hydride (DMAH) as raw material gases as the source gas. Compared to TMA, DMAH is composed of hydrogen bonded instead of methyl groups. To investigate the change in interfacial state between these two insulating films, capacitors with metal/insulating film/hydrogen-terminated diamond/metal structures were fabricated, and the capacitance-voltage characteristics were used to calculate the density of interfacial defect levels using the high-low method. The results show that the defect density decreases in the case of DMAH.

Free Research Field

半導体素子

Academic Significance and Societal Importance of the Research Achievements

ダイヤモンドパワー半導体素子は，高温環境に耐え，高耐圧，高周波数動作が可能であると期待され次世代の電力変換素子と位置づけられているが，その材料の性能を十分に発揮できていない．本研究では特に素子の特性を左右するダイヤモンドと絶縁膜界面状態の改質に着目し，トランジスタ素子性能の向上を目的とした．結果，素子に用いられる絶縁膜の成膜原料を変更することで，素子界面に形成される電気的な欠陥を50%以下に低減することに成功した．これにより素子の電力損失低減が期待できる．この手法は装置の変更など大掛かりな改善を必要としないため，比較的普及しやすい手法であると言える，