【公開日：2024.07.25】【最終更新日：2024.05.21】
課題データ / Project Data
課題番号 / Project Issue Number
23UT1149
利用課題名 / Title
ナノポア内温度測定のためのnano-RTDの製作
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）高度なデバイス機能の発現を可能とするマテリアル/Materials allowing high-level device functions to be performed
キーワード / Keywords
Solid-state nanopore, Joule heating, nanoscale resistance temperature detector （nano-RTD）, thin film deposition,センサ/ Sensor,蒸着・成膜/ Vapor deposition/film formation,スパッタリング/ Sputtering,ダイシング/ Dicing,光リソグラフィ/ Photolithgraphy,ナノワイヤー・ナノファイバー/ Nanowire/nanofiber
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
程 馨毅,PAUL SOUMYADEEP,NAG SARTHAK,王 智宇, 徐 偉倫,大宮司 啓文
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
Makoto Fujiwara,Ayako Mizushima
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-505：レーザー直接描画装置 DWL66+2018
UT-701：川崎ブランチスパッタリング装置
UT-700：4インチ高真空EB蒸着装置
UT-906：ブレードダイサー
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
Boiling heat transfer at nano to microscale is of particular interest for thermal management of next-generation electronic devices and metal heat treatment industries. In this regard, investigation of the stability of the vapor surface nanobubbles and their heat transport characteristics is vital for nanoscale boiling diagnostics. In the present work, we are developing a nanoscale resistance temperature detector (nano-RTD) for wall temperature measurement at nanosecond resolutions during solid-state nanopore boiling. The proposed design consists of gold microelectrodes and Tungsten nanoelectrode ring. The two metals are selected such that the RTD sensor has a high electric current sensitivity to nanopore wall temperature variation as shown in Fig.1.
実験 / Experimental
Fabrication process of nanoscale resistance temperature detector is as follows: 1) Dicing of 4-inch-wide Si/SiNx wafer (200 mm thick Si substrate with 100 nm silicon nitride thin film deposited on either side) into 22 mm x 22 mm square chips using DAG3650 Disco automatic dicing saw. as shown in Fig.2. 2) Organic cleaning using acetone and isopropanol followed by oxygen plasma cleaning using SAMCO FA-1 plasma etcher. 3) Spin coating of ZEP520A (0 rpm / 1 sec. - 500 rpm / 5 sec. – 4,000 rpm / 60 sec.) as EB resist and baking at 180°C. 4) Photolithography (DWL66+) of microelectrode pattern and alignment markers (Layer 1 in Fig. 1b and shown in Fig.3). 5) Development: ZND-50 60 sec., MIBK 10 sec., IPA 10 sec., dry with N2 gun. 6) Thermal evaporation deposition of 5 nm Ti adhesion layer and 95 nm Au layer using Ultra high vacuum evaporator NSP2 as shown in Fig.4. Resist liftoff using ASAP LOA34-805-09. 7) Sputtering of 20 nm thick Tungsten(with mixture of Gallium) layer using FIB. 8) Resistance testing by a resistance detector. 9) Sputtering of 100nm-thick SiNx layer on top of the electrodes using SHIBAURA CFS-4EP-LL. 10) RIE with pattern making by Photolithography DWL66+ and dry etching by ICP-RIE ULVAC CE300I and wet etching with KOH from backside to open window. 11) Focused ion beam etching of 400 nm diameter nanopore at the center of the Pt-ring nanoelectrode. (yet to be done). The SEM image of deposited Tungsten-RTD is shown in Fig.5(a), the zoomed-in SEM image Tungsten nano-RTD ring is shown in FIg. 5(b, and th optical micrograph for Tungsten microelectrode and FIB-CVD exposed zone is shown in Fig.5(c).
結果と考察 / Results and Discussion
The result of each fabrication process of nanoscale resistance temperature detector is as follows: 1) Precious Dicing using DAG3650 Disco automatic dicing saw. 2) Organic cleaning using acetone and isopropanol followed by oxygen plasma cleaning using SAMCO FA-1 plasma etcher. 3) Spin coating of JSR (0 rpm / 1 sec. - 500 rpm / 5 sec. – 3,000 rpm / 60 sec.) as EB resist and baking at 120°C.4 ) Photolithography (DWL66+) of microelectrode pattern and alignment markers. 5) Development: ZND-50 60sec., MIBK 10sec., IPA 10sec., dry with N2 gun. 6) Thermal evaporation deposition of 5 nm Ti adhesion layer and 95 nm Au layer using Ultra high vacuum evaporator NSP2. Resist liftoff using ASAP LOA34-805-09. 7) Sputtering of 20 nm thick Tungsten layer using FIB-CVD. 8) Resistance texting by resistance detector whose sensitivity up to 99.9% . 9) Sputtering of 100nm-thick SiNx layer on top of the electrodes using SHIBAURA CFS-4EP-LL and a special hard mask made by MUC21-ASE. 10) Sputtering of 100nm-thick Cr layer on top of the chip using SHIBAURA CFS-4EP-LL. 11) RIE with pattern making by Photolithography DWL66+ and dry etching by ICP-RIE ULVAC CE300I and wet etching with KOH from backside to open window. 12) Focused ion beam etching of 400 nm diameter nanopore at the center of the Pt-ring nanoelectrode. (yet to be done)
図・表・数式 / Figures, Tables and Equations
Fig. 1. (a) Schematic showing experimental setup for nanoscale boiling using resistive pulse sensing for nanobubble sensing, hydrophone for boiling acoustics and RTD sensor for boiling thermometry (b) Schematic showing RTD sensor embedded inside SiNx membrane (c) Pt-ring for nanopore wall temperature measurement.
Fig. 2 The design of dicing pattern on the special wafer.
Fig. 3(a) Alignment marker made by Photolithography DWL66+ with dose of 190 and (b) design of alignment marker.
Fig. 4 Deposition of Au by NSP2.
Fig. 5 (a) SEM image of deposited Tungsten-RTD (b) zoomed-in SEM image Tungsten nano-RTD ring and (c) optical micrograph for Tungsten microelectrode and FIB-CVD exposed zone.
Fig. 6 Resistance testing of RTD by a resistance detector.
Fig. 7 (a) Deposition of SiNx thin film and (b) Hard mask
Fig. 8 Deposition of Cr thin film.
Fig. 9 (a) Image of backside window after dry etching, (b) Wet etching process with glass tube and KOH and (c)Image of backside window after wet etching.
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
PAUL Soumyadeep, ITO Yusuke, HSU Wei-Lun, DAIGUJI Hirofumi, Thermodynamic bifurcations in solid-state nanopores, Physical Review Research, Vol. 6 (1), 013110, 2024. DOI : https://doi.org/10.1103/PhysRevResearch.6.013110
PAUL Soumyadeep, CHENG Xinyi, ITO Yusuke, HSU Wei-Lun, DAIGUJI Hirofumi, Boiling Bifurcations and Hysteresis in Solid-state Nanopores, APS March Meeting 2024, M40.00002, 2024.
CHENG Xinyi, PAUL Soumyadeep, ITO Yusuke, HSU Wei-Lun, DAIGUJI Hirofumi, 61st National Heat Transfer Symposium of Japan, 2024 (Submitted)
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