Atmospheric pressure thermal plasma jet generation by MEMS integration

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K20911
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 14:Plasma science and related fields
• Research Institution: Hiroshima University
• Principal Investigator: Higashi Seiichiro 広島大学, 先進理工系科学研究科(先), 教授 (30363047)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 大気圧プラズマ / MEMS

Outline of Final Research Achievements

In this study, we focus on the formation of micrometer-scale atmospheric pressure thermal plasma jet (TPJ) on the basis of Micro Electro Mechanical Systems (MEMS) technique, and development of integration technology for multiple nozzle TPJ. 500-nm-thick SiO2 layer was formed on silicon (100) wafer by pyrogenic oxidation as the hard mask and wet etching was performed to form cone-shaped structure for cathode and inverse-cone structure for anode.
SiO2 hard mask and TMAH etching under various mask shape, size, and etching conditions, a 135-um-high smooth cone shape was successfully formed using 15% TMAH and 20% IPA for 285 min. On the other hand, inverse-cone shape with 188 um depth was formed by applying 20% TMAH etching for 240 min. W film was deposited on cone shape cathode and heated by flowing DC current to observe radiation from the W cathode. We have successfully developed the basic techniques for TPJ generation by miniaturized electrodes based on MEMS technology.

Free Research Field

半導体工学

Academic Significance and Societal Importance of the Research Achievements

本研究では大気圧熱プラズマ発生にMEMS技術を応用するという従来にない発想に基づき実験をおこなった。これまでMEMSは加速度センサや振動発電といった機械的機能の発現に着目されていたが、本研究では極微細プラズマの発生にも応用可能であることを示した。この様な異種技術の融合により新たな研究領域を開拓することは学術的意義と同時に、従来実現できなかった新たな応用分野の開拓や産業上の応用への発展の可能性を有することから、社会的意義を有するものと考えられる。