Development of high rate glancing angle deposition techniques with oxygen radical source for the fabrication of titanium oxide films with excellent photo-catalytic properties

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K04682
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Tokyo Polytechnic University
• Principal Investigator: HOSHI Yoichi 東京工芸大学, 工学部, 名誉教授 (20108228)
• Research Collaborator: KOBAYASHI shin-ichi ; YASUDA yoji
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 斜め入射堆積 / 酸素ラジカル源 / 酸素イオン / 高速スパッタ / 光触媒材料 / ポーラス膜 / 酸化チタン膜 / 酸化タングステン膜

Outline of Final Research Achievements

Oxygen radical assisted glancing angle reactive deposition technique with an ECR oxygen plasma source was developed and deposition rate above 30 nm/min was realized at an incidence angle above 60°. Furthermore, high rate reactive sputter-deposition technique with two sputtering sources (Ti supply sputtering source and oxygen radical supply sputtering source) was also developed for the fabrication of the TiO2 films. We found that sputtering rate was increased significantly by the increase of sputtering voltage in reactive sputtering of WO3 and developed a high rate sputter-deposition technique above 100 nm/min. In addition, suppression of the incidence to negative oxygen ions emitted from the target surface during sputtering was necessary to obtain a porous WO3 film with an excellent gasochromic properties and porous WO3 film with excellent operties was realized by the sputtering in off axis substrate arrangement and sputtering at a high gas pressure.

Free Research Field

電気電子材料

Academic Significance and Societal Importance of the Research Achievements

ポーラスで表面積が大きく、かつ結晶性も良好な酸化物膜を高堆積速度で得る方法を確立することは、光触媒など物質の表面で起こる現象を利用するためには極めて重要である。本研究で開発した斜め入射堆積法を用いれば、容易に表面積が極めて大きく特性も良好な光触媒用の酸化チタン膜が作製できる。
また従来のマグネトロンスパッタ法などで酸化物を反応スパッタ法で膜を作製しようとすると、金属のスパッタと比較して堆積速度が急減して作製が困難であったWO3膜や酸化チタン膜の作製で、堆積速度を容易に百倍以上に増加させることができる方法を見出したことは極めて重要で、酸化物のみならず様々な化合物のスパッタで利用できる方法である。