【公開日：2025.06.10】【最終更新日：2025.05.26】

課題データ / Project Data

課題番号 / Project Issue Number

24UT1192

利用課題名 / Title

Frabrication of a nanopore device

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）次世代ナノスケールマテリアル/Next-generation nanoscale materials（副 / Sub）-

キーワード / Keywords

nanopore, STEM, FIB,原子層薄膜/ Atomic layer thin film,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

HSU Chien,OU Che-Wei,HSU Wei-Lun

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-606：汎用平行平板RIE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)

For nanopore fabrication of two-dimensional materials, the electromagnetic lens focuses the electron beam in a high-vacuum system under STEM with an acceleration voltage of up to several hundred kV to penetrate the suspended samples. The pore size could be adjusted by the irradiation time. However, due to the local defects and orientation of molecules, the control of the pore shape was extremely challenging. Our group previously developed a multi-drilling method to create nanopore with sub-nanometer spatial resolution, enabling reproducible pore size and shape for commercialization. However, STEM drilling is costly and requires advanced operational skills. More importantly, the multiple drilling process takes extra time for fabrication, prohibiting the mass production for nanopore arrays. In this project, we aim to develop a lithography-based pore fabrication method for nanopore arrays on monolayer molybdenum disulfide: MoS₂.

実験 / Experimental

The sample prepared after E-beam process can be loaded into RIE-10NR (UT-606) for dry etching process. It is possible to adjust the recipe by inputting the information into the device by using the control panel. There are five different gases that can be chosen: Ar, O₂, CF₄, SF₆, and CHF₃. It is possible to make any combination of these gases into the recipe. After the dry etching process, the MoS₂ monolayer should be etched down, and a pore array can be created. The chip purchased is first milled by FIB to create a 1 μm diameter window. The prepared MoS₂ monolayer is then transferred to the chip to cover it. Before E-beam, the sample is cleaned by ozone plasma for 5 min to make sure the PMMA photoresist can attach well over the target position. After E-beam process, it is developed and goes through the dry etching process. The sample prepared is examined by using STEM to check the current recipe is feasible.

結果と考察 / Results and Discussion

The proposed membrane fabrication process, starting from a blank chip, a 1 μm diameter window was created by FIB. A dry transfer method was applied for transferring MoS₂ monolayer over a FIB milled chip. After coating a 50 nm thickness PMMA over the MoS₂ monolayer, a dry etching process was conducted with the recipe obtained from the testing run. The result was scrutinized by STEM. A 60 nm fully etched pore was found, several partially etched pores were observed. The 200 nm pore spacing matches well with the pattern designed. However, an additional process is suggested to remove PMMA. The current results proved that the proposed E-bean fabrication process is applicable for creating a 60 nm pore array with 200 nm pore spacing on a MoS₂ monolayer with 1 μm in diameter FIB milled pore. 

図・表・数式 / Figures, Tables and Equations

Fig. 1 The specified pore array pattern can be observed near the FIB milled window with a pore spacing of ca. 200 nm. 

Fig. 2 Pore array pattern on a free-standing MoS2 monolayer covering a FIB milled window with a diameter of 1 μm. The size of each pore is ca. 60 nm, and the pore spacing ca. 200 nm. 

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

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.

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