【公開日：2025.06.10】【最終更新日：2025.04.08】
課題データ / Project Data
課題番号 / Project Issue Number
24TU0004
利用課題名 / Title
メタマテリアルデバイスの作製/Fabrication of Mtamaterial Dvices
利用した実施機関 / Support Institute
東北大学 / Tohoku Univ.
機関外・機関内の利用 / External or Internal Use
外部利用/External Use
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）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（副 / Sub）-
キーワード / Keywords
フォトニクスデバイス/ Nanophotonics device,メタマテリアル/ Metamaterial,光リソグラフィ/ Photolithgraphy,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)
佐々木 玲子
所属名 / Affiliation
理化学研究所
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
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
TU-201：DeepRIE装置#1
TU-307：金属顕微鏡
TU-310：レーザ／白色共焦点顕微鏡
TU-058：マスクレスアライナ
TU-060：現像ドラフト
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
This study proposes a silicon pillar-based terahertz metasurface for polarization space-division multiplexing. By optimizing pillar geometry and spatial arrangement, it enables multi-polarization generation, modulation, and analysis. The M-4D device converts a linearly polarized wave into four beams with distinct polarization angles, while M-2B and M-4B generate vector Bessel beams. Fabricated on a high-resistivity silicon substrate using photolithography and deep silicon etching, the design is validated through simulations and experiments. This approach advances metasurface-based polarization control with potential applications in imaging, sensing, communication, and beyond.
実験 / Experimental
(1) Mask Fabrication: First, the mask pattern was
exposed onto a Cr-coated quartz substrate coated with AZ1350 positive
photoresist using the Maskless Aligner TU-058. Development was carried out in
the Draft Chamber for Development TU-060, followed by Cr pattern transfer using
a Cr etchant. The remaining photoresist was removed in the Draft Chamber TU-001
using a H2SO4:H2O2 = 5:1 solution, yielding the final mask. This mask can be used in
subsequent traditional photolithography processes, as shown in the figure 1 Photos and
Microscopic Images of the Mask.
(2) Photolithography Process: A high-resistivity silicon substrate (1 mm thick)
was used. An adhesion promoter (OPA) was spin-coated using the Mikasa Spin
Coater TU-051 and baked on the Hot Plate TU-054. PR800-200cp positive
photoresist was then spin-coated using the Spin Coater TU-052 and baked on the
Hot Plate TU-054. The mask was mounted on the Double-Side Aligner TU-056 for
exposure. After exposure, development was performed in the Draft Chamber for
Development TU-060, resulting in a patterned photoresist on the silicon
substrate （Figure 2).
(3)Deep Silicon Etching Process:
Deep silicon etching was conducted using DeepRIE #1 TU-201, with etching depth
monitored and measured using the Laser/White Light Confocal Microscope TU-310.
After processing, the final sample was inspected using the Microscope TU-307.
The final results are shown in the figure Photos and
Microscopic Images of the Etched Sample.
結果と考察 / Results and Discussion
The required etching depth is 200 µm. The actual etching depths measured at different positions using the Laser/White Light Confocal Microscope TU-310 are shown in the picture below （Figure 3). The results indicate that the central region has a shallower etching depth compared to the edges, exhibiting a certain degree of non-uniformity. Optimization may be achieved by adjusting etching parameters such as etching time, passivation time, and gas pressure.
図・表・数式 / Figures, Tables and Equations
Figure 1. Photos and Microscopic Images of the Mask
Figure 2. Photos and Microscopic Images of the Etched Sample
Figure 3. Etching Depth Measurement Results
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
Reference: Yuehong
Xu, Yuma Takida, Tetsu Suzuki, Hiroaki
Minamide, Terahertz-Wave Polarization Space-Division Multiplexing
Meta-Devices based on Spin-Decoupled Phase Control. Advanced Science. 2025, 12,
2412688. https://doi.org/10.1002/advs.202412688
Acknowledgements: This
work was supported (in part) by RIKEN Incentive Research Project and (in part)
by Innovative Science and Technology Initiative for Security Grant Number
JPJ004596, ATLA, Japan. We thank Prof. Hiroaki Minamida in RIKEN, Prof.
Hiromasa ITO in RIKEN and Tohoku University, Prof.
Masahiro Henmi and Masaaki Moriyama in Tohoku University, previous and present
researchers in RIKEN RAP, and researchers in collaboration works for effective
support and discussion.
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)
-
Yuehong Xu, Terahertz‐Wave Polarization Space‐Division Multiplexing Meta‐Devices based on Spin‐Decoupled Phase Control, Advanced Science, 12, (2024).
DOI: https://doi.org/10.1002/advs.202412688
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- Yuehong Xu, Yuma Takida, Tetsu Suzuki, Hiroaki Minamide, “Enhanced control of multi-beam THz-wave polarization using spin-decoupled phase engineering in metasurfaces,” the 45th Annual Meeting of the Laser Society of Japan, Hiroshima, Japan (Jan. 21-23, 2025)
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