Synthesis of zinc oxynitride thin films by atmospheric pressure radical-assisted mist CVD and elucidation of the radical reaction mechanism

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03526
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 14030:Applied plasma science-related
• Research Institution: Meijo University
• Principal Investigator: Takeda Keigo 名城大学, 理工学部, 教授 (00377863)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ラジカル / ミストCVD / 大気圧プラズマ / 酸化亜鉛 / 酸窒化物

Outline of Final Research Achievements

In this study, a radical-assisted mist chemical vapor deposition (CVD) device based on an atmospheric pressure plasma source has been constructed to realize a process technology for synthesizing thin films of metal oxynitrides as well as to further reduce the temperature of the metal oxide thin film deposition process in the mist CVD. We have analyzed the effects of the supplied radical species on the growth of zinc oxide thin films in the mist CVD and on the synthesized thin films. The NH radical irradiation was significant in the etching reaction of the film, while NO radical irradiation was effective in promoting film growth with a decrease in the substrate temperature. Moreover, in the radical-assisted mist CVD using an ethanol solution with a zinc acetate as a mist raw material, the thin film was synthesized by controlling the surface reactions of NH radicals. As results, we succeeded in confirming a small amount of nitrogen in the thin films from the results of X-ray analysis.

Free Research Field

プラズマ理工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、ミスト化学気相堆積（CVD）の更なる低温化に加え、酸窒化物の薄膜合成技術の実現を目指し、大気圧プラズマをベースとしたラジカル支援ミストCVD装置を構築した。本装置では、分光技術による分析結果をもとに、NHおよびNOラジカルの供給制御技術を実現し、供給するラジカル種に応じて表面反応を制御することで、薄膜の合成温度の低温化、合成速度の向上などを実現した。以上の結果は、ミストCVD技術の高度化のみならず、大気圧下のラジカル生成反応の理解とその制御といった学術基盤の強靭化に加え、大気圧プラズマを用いた材料プロセスの発展に繋がり、学術・産業の両面に与える影響は極めて大きいといえる。