Development of a low temperature fabrication method of insulator films applicable to next generation electronic devices by the electrochemical oxidation method

2021 Fiscal Year Final Research Report

• Project/Area Number: 17K06804
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic materials/Physical properties
• Research Institution: Tokyo University of Technology
• Principal Investigator: TAKAHASHI Masao 東京工科大学, 工学部, 教授 (00188054)
• Co-Investigator(Kenkyū-buntansha): 茂庭 昌弘 東京工科大学, 工学部, 教授 (50704623)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: 複合アニオン化合物薄膜 / 電気化学的酸化 / 低温薄膜創製 / 絶縁体薄膜 / 抵抗変化型メモリ / 価電子制御

Outline of Final Research Achievements

The new method to form mixed-anion compound layers has been developed and the formed insulator layers are found to be applicable to the resistance random access memory (ReRAM), which is one of next generation electronic devices. The formation method consists of the electrochemical oxidation in organic solutions under atmospheric pressure at ambient temperature. TaOxNy layers were formed on Ta substrates by the electrochemical oxidation method in methanol solutions of tetramethyl ammonium hydroxide with applying +5 V (vs. Pt) to Ta substrates and the prepared <Al/TaOxNy/Ta> samples showed typical current-voltage (I-V) characteristics as the ReRAM devices. It was found that water concentrations in organic solutions are able to control the anion deficiency of formed compound layers. Furthermore, the method of producing insulating layers with a high cumulative probability of bipolar-type I-V characteristics has been developed.

Free Research Field

無機材料化学

Academic Significance and Societal Importance of the Research Achievements

複合アニオン化合物を大気圧下で室温創製できる新しい合成方法の開発に成功した。有機溶液中で数Vの電圧印加の電気化学反応を用いた合成方法であり、生成する化合物中のアニオン欠損量を反応溶液の水分濃度で制御でき、生成層を絶縁膜に用いて抵抗変化型メモリ（ReRAM）デバイスを作製できることを見出した。
低消費エネルギーの次世代型メモリデバイスであるReRAMの製造工程では、高真空装置の駆動などで絶縁膜作製に多くのエネルギーが使われている。本研究の成果をReRAMの絶縁膜製造工程に応用すれば、製造時のエネルギー消費量を圧倒的に低減でき、持続可能な社会の実現に大きく貢献できる。