【公開日：2023.07.28】【最終更新日：2023.04.17】
課題データ / Project Data
課題番号 / Project Issue Number
22TU0069
利用課題名 / Title
圧電薄膜MEMSデバイス開発 / Development of thin film piezoelectric MEMS devices
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
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）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
マイクロミラー/Micromirror, ピエゾ抵抗センサー/Piezoresistor, フィードバック制御/Feedback control,蒸着・成膜/Evaporation and Deposition,ALD,スパッタリング/Sputtering,リソグラフィ/Lithography,膜加工・エッチング/Film processing and Etching,アクチュエーター,MEMSデバイス
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)
Vergara Andrea
所属名 / Affiliation
東北大学大学院工学研究院
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
Qi Xuanmeng, 関口拓真, 福士海伊
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
森山雅昭
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-105：中電流イオン注入装置
TU-058：マスクレスアライナ
TU-170：ゾルゲル自動成膜装置
TU-206：アルバックICP-RIE#2
TU-164：酸素加圧RTA付高温スパッタ装置
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
The facilities in Tohoku University (Nishizawa Center) were used to develop piezoelectric MEMS devices based on PZT thin film. A MEMS micromirror for quasi-static laser scanning with PZT actuation and piezoresistive sensing for feedback control, and test devices to investigate the feasibility of simultaneous poling of several piezoelectric devices were made using equipment for microfabrication such as automatic sol-gel PZT deposition machine, RTA sputter, Ion Implantation, Furnaces for thermal oxidation and annealing, Maskless Aligner, etc.
実験 / Experimental
The micromirror device was fabricated in the following manner: an SOI wafer was prepared by thermal oxidation (XL-7), then the sensors were fabricated by B and P ion implantation (NH-20SR), with an intermediate annealing (XL-7) and rapid thermal annealing (AG410). Then, the PZT actuator was fabricated by Pt/Ti sputtering (21-0604) and PZT solgel deposition (PZ-604). Later, the device was released by ICP-RIE (CE-300I). The cantilevers for studying poling of multiple devices were similarly processed for release.
The mirror’s dynamic response was evaluated for derivation of a PID control system using the built-in sensors. The system’s performance was estimated by simulation.
The cantilevers were poled on a hot plate simultaneously by having connected top electrodes. The P-E hysteresis curve and tip displacement were measured before and after poling (after cutting the connection).
結果と考察 / Results and Discussion
From previous sensor measurements and FEM simulation, it was found that the output signal of the sensors located in the actuators (longitudinal) of the micromirror is about 300 times higher than in the torsion bar (transverse). This difference resulted in significant signal-to-noise ratio (SNR) reduction compared to the typical sensor position at the torsion bar. Fig. 1A and B shows the SEM pictures of both types of sensor location, and Fig. 1C shows the simulated scanning performance of the feedback-controlled micromirrors at 50 Hz. The scan on the mirror with transverse sensors is noisier.
For the study on simultaneous poling of multiple devices, Fig. 2A shows the devices and Fig. 2B and C show the main results. After being poled together, the devices were separated by cutting the connecting wire with laser and measured again. Both the increase in displacement and the P-E curves look uniform for the devices. The results suggest that poling several devices at the same time could be a viable process.
図・表・数式 / Figures, Tables and Equations
Fig. 1 Micromirror results. A) SEM picture of mirror with sensors on the actuator. B) SEM picture of mirror with sensors on the torsion bar. C) Simulated performance of feedback-controlled slow scan (50 Hz sawtooth).
Fig. 2 Simultaneous multiple poling results. A) Microscope picture of devices. Connection cut by laser for individual evaluation (inset). B) Effects of simultaneous poling in the displacement and C) P-E curve.
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
・参考文献 A. Vergara et al., J. Micromech. Microeng., 30 (2020) 115020, A. Vergara et al, Sens. Actuators A, 332 (2021) 113131.
・本研究の一部は東北大学男女共同参画推進センター（TUMUG）が実施するTUMUG支援事業（男女共同参画・女性研究者支援事業）の支援を受けたものである。
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)
-
Andrea Vergara, Design and fabrication of non-resonant PZT MEMS micromirror with buried piezoresistors for closed loop position control, Journal of Micromechanics and Microengineering, 33, 014001(2022).
DOI: 10.1088/1361-6439/aca101
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- Andrea Vergara，Samuel Hsieh, 田中秀治, “Simultaneous poling of multiple piezoelectric devices” 第39回「センサ・マイクロマシンと応用システム」シンポジウム （ポスター発表）, 令和4年11月16日．
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