【公開日：2024.07.25】【最終更新日：2024.05.30】

課題データ / Project Data

課題番号 / Project Issue Number

23UT1140

利用課題名 / Title

ダイヤモンドライクカーボンの超疎水性表面

利用した実施機関 / Support Institute

東京大学 / Tokyo Univ.

機関外・機関内の利用 / External or Internal Use

内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)

技術領域 / Technology Area

【横断技術領域 / Cross-Technology Area】（主 / Main）加工・デバイスプロセス/Nanofabrication（副 / Sub）-

【重要技術領域 / Important Technology Area】（主 / Main）その他/Others（副 / Sub）-

キーワード / Keywords

電子線描画,　膜加工・エッチング、撥水性,スパッタリング/ Sputtering,電子線リソグラフィ/ EB lithography,膜加工・エッチング/ Film processing/etching

利用者と利用形態 / User and Support Type

利用者名（課題申請者）/ User Name (Project Applicant)

大宮司 啓文

所属名 / Affiliation

東京大学大学院工学系研究科機械工学専攻

共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes

Shamim Jubair Ahmed,髙橋　幸成

ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes

利用形態 / Support Type

（主 / Main）機器利用/Equipment Utilization（副 / Sub）-

利用した主な設備 / Equipment Used in This Project

UT-800：クリーンドラフト潤沢超純水付
UT-703：8インチ汎用スパッタ装置
UT-500：高速大面積電子線描画装置
UT-603：汎用高品位ICPエッチング装置
UT-600：汎用ICPエッチング装置

報告書データ / Report

概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)

     In Takeda super cleanroom of U. Tokyo ARIM, we usually fabricate micropillars of various dimensions on DLC substrate to make superhydrophobic surface (SHS). In 2021, we developed the necessary recipes for various processes (details in section 2) by working together with Dr. Eric and completed necessary training to run all the related equipment independently. A schematic of the micropillars is shown in Fig. 1.
     In 2022, we made several samples having different micropillar thickness (t =3 and 25 µm), pitch (p =9, 15 and 75 µm) and height (h₁ = 3, 6 and 8 µm). These surfaces were used in the study of wetting transition (from Cassie-Baxter to Wenzel transition) of evaporating fakir droplets. One journal [1] and several conference proceedings [4-10] were published as an outcome of this study.
     In 2023-2024, we have initiated a new study on the condensation behavior of micro-droplets on SHSs with multiscale roughness. However, this time we changed the layout file only for the EB lithography step, the other process remained same as the previous fabrication method. A schematic of the latest interface design is shown in Fig. 2. The related publications (journal [2], thesis [3] and conference proceedings [8-10]) on the current study are mentioned in section 5. 

実験 / Experimental

【利用した主な装置】
クリーンドラフト潤沢超純水付、8 インチ汎用スパッタ装置、 高速大面積電子線描画装置、汎用高品位 ICP エッチン グ装置、汎用 ICP エッチング装置
【実験方法】
A schematic of the micropillar fabrication process on DLC substrate is shown in Fig. 3 and processes are described below:
i. Deposit DLC thin film (10 µm thick) on Si wafer by CVD (performed outside of Takeda-CR).
ii. Cleave the wafer into 2*2 cm chip manually.
iii. Organic cleaning using Acetone, ethanol, and water.
iv. Sputtering of Al hard mask (100 nm thick) using SIH-450 ULVAC.
v. O₂ plasma ashing to improve adhesion of surface.
vi. Spin coat of OAP (0 rpm/1sec. – 500rpm/5sec. – 3,000rpm/30sec.) and ZEP520A (0 rpm/1sec. - 500rpm/5sec. – 4,000rpm/60sec.) as EB resist.
vii. EB lithography (ADVANTEST F5112+VD01), dose: 104 µC/cm².
viii. Development: ZND-50 60sec., MIBK 10sec., IPA 10sec., dry with N₂ gun.
ix. Etching of Al hard mask (Cl₂ plasma) with ICP-RIE ULVAC NE-550 (etching time 45 sec.)
x. Etching of DLC layer (O₂ plasma) with ICPRIE-ULVAC CE-300I. (Etching rate approximately 0.38 µm per minute).
xi. Removal of Al hard mask and resist by chemical etching (Al etchant was used for 5 min) 
xii. Teflon coat of pillars with DRIE SPPT MUC21 ASE Pegasus. (Film thickness 50 nm and depo time 30 sec.)
xiii. Check the micropillar dimensions in SEM.

結果と考察 / Results and Discussion

     This time we have fabricated surfaces with two different wall (shown in Fig. 2) dimensions (200 and 400 µm) and one surface micropillars only without wall. The pitch (16 µm) and height (8 µm) of micropillars for all samples were the same. Below we show the SEM images (top and 45-degree views) of various wall-enclosed micropillar samples we made in 2023-2024 are shown in Fig. 4a-f. Due to the well-established recipe and cutting-edge equipment facility of Takeda cleanroom, we could obtain micropillars with high precision of dimensions.

図・表・数式 / Figures, Tables and Equations

Fig. 1: Key dimensions of SHS with micropillars

Fig. 2: Top view of the new layout made in 2023-2024

Fig. 3: Fabrication process of micropillars on DLC 

Fig. 4a: Top SEM image of sample without any wall

Fig. 4b: 45-degree SEM image of sample without any wall

Fig. 4c: Top SEM image of wall size of 200 μm

Fig. 4d: 45-degree SEM image of wall size of 200 μm

Fig. 4e: Top SEM image of wall size of 400 μm

Fig. 4f: 45-degree SEM image of wall size of 400 μm

その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)

・10.1038/s41598-023-29163-1・Shamim, J.A., Goswami, A., Takahashi, Y., Shaukat, N., Hsu, W.-L., Choi, J., Daiguji, H., “Suppression of wetting transition on evaporative fakir droplets by using slippery superhydrophobic surfaces with low depinning force,” JSME Thermal Engineering Conference, Oct. 9-10, 2022, Tokyo, Japan.
・髙橋 幸成 , SHAMIM A. Jubair, SHAUKAT Nadeem, MOUTERDE Timothée, 徐 偉倫, 崔 埈豪, 大宮司 啓文, “超撥水性表面の開発 Cassie-Baxter から Wenzel への転移の遅延に向けて,” 日本冷凍空 調学会年次大会, 岡山 (2022 年 9 月 8 日) ・Shamim, J.A., Goswami, A., Takahashi, Y., Shaukat, N., Hsu, W.-L., Daiguji, H., “Wetting transition of evaporating fakir drop on microstructured superhydrophobic surfaces: Model development and validation in surface evolver,” 16th International Conference on Heat Transfer, Fluid Mechanics, and Thermodynamics (HEFAT), Aug. 8-10, 2022 (virtual). ・Shamim, J.A., Takahashi, Y., Mouterde, T., Hsu, W.- L., Choi, J., Daiguji, H., “Pressure-driven wetting transition of evaporating droplets on textured Diamondlike-carbon substrates,” The 59th Japan Heat Transfer Symposium, May 18-20, 2022, Gifu, Japan.

成果発表・成果利用 / Publication and Patents

論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)

口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.

1. Shamim, J.A., Takahashi, Y., Hsu, W.-L., Harish, S., Cheng, Z., Hoque, M.J., Choi, J., Miljkovic, N., and Daiguji, H., “Slippery Superhydrophobic Surfaces to Suppress Cassie-Baxter to Wenzel Transition,” Microflow and Interfacial Phenomena Conference (μFIP), June 18-21, 2023, Evanston, Illinois, USA.
2. 髙橋 幸成, SHAMIM A. Jubair, 神代 渉, CHENG Zhizhong, SIVASANKARAN Harish, HOQUE Juhidul Muhammad, 徐偉倫 , 崔埈豪 , MILJKOVIC Nenad, 大宮司啓文, “階層粗さを有す る超撥水性表面及び滑液性表面上における水滴の凍 結遅延に関する研究,” 日本冷凍空調学会年次大会, 東京 (2023 年 9 月 7 日)
3. 髙橋 幸成 SHAMIM A. Jubair, 神代 渉, 徐 偉倫, 崔 埈豪, 大宮司 啓文, “階層粗さを有する囲い壁 付きマイクロピラーにおける凝縮水滴の自発的な跳 躍と合体現象に関する研究,” 日本機械学会熱工学コ ンファレンス 2023, 神戸 (2023 年 10 月 15 日)
4. 髙橋 幸成, SHAMIM A. Jubair, 徐 偉倫, 崔 埈豪, 大宮司 啓文 “ダイヤモンドライクカーボン製の超撥水 性表面における fakir 水滴及び 凝縮水滴の CassieBaxter 状態から Wenzel 状態への濡れ転移の抑制.” 日本冷凍空調学会論文集, 2023, 23-19NR_OA.

特許 / Patents

特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件