カテゴリ: 論文誌(論文単位)グループ名: 【E】センサ・マイクロマシン部門発行日: 2018/02/01タイトル(英語): Evaluation of Capacitance Changes of Capacitive Micromachined Ultrasonic Transducers for Ultrasonic Diagnoses by Charge-Injection著者名: 青野 宇紀（（株）日立製作所 研究開発グループ 機械イノベーションセンタ），吉村 保廣（（株）日立製作所 研究開発グループ 機械イノベーションセンタ），町田 俊太郎（（株）日立製作所 研究開発グループ エレクロトニクスイノベーションセンタ）著者名(英語): Takanori Aono (Research and Development Group, Center for Technology Innovation - Mechanical Engineering, Hitachi, Ltd.), Yasuhiro Yoshimura (Research and Development Group, Center for Technology Innovation - Mechanical Engineering, Hitachi, Ltd.), Shuntaキーワード: 超音波探触子，CMUT，絶縁膜，電荷注入 Ultrasonic probe，Capacitive micromachined ultrasonic transducers，Insulating film，Charge-injection要約(英語): This research reports capacitance-voltage (CV) changes of capacitive micromachined ultrasonic transducers (CMUT) for ultrasonic diagnoses. The CMUT constitutes an electrostatically vibrating film, which is fabricated by deposition processes of SiO2 and SiN films as insulator and TiN and Al films as top electrode on an Si substrate. The ultrasonic waves are transmitted by addition of AC voltage between the top electrode and the Si substrate, whereas the reflective ultrasonic wave are received with the vibrating film and converted to the electrical signals for ultrasonic diagnostic images. There is a problem that the CV changes of CMUT occur due to charge-injection into the insulator, since a high AC and DC voltages are applied for driving the vibrating film. Thus, it is necessary to suppress the change in CV characteristics of the CMUT due to charge-injection. It is clarified that the CV drift due to charge-injection can be decreased by forming the top electrode so as to cover the vibrating film. Also, the CV drift is able to be suppressed by setting the driving voltage to be equal to or less than the collapse voltage.本誌: 電気学会論文誌E（センサ・マイクロマシン部門誌） Vol.138 No.2 （2018）本誌掲載ページ: 59-65 p原稿種別: 論文／日本語電子版へのリンク: https://www.jstage.jst.go.jp/article/ieejsmas/138/2/138_59/_article/-char/ja/
