Comparison of Si3N4-SiO2 and SiO2 Insulation Layer for Zero-Bias CMUT Operation Using Dielectric Charging Effects
In this letter, we report the characteristics of zero-bias capacitive micromachined ultrasonic transducers (CMUTs) in various aspects, considering the transmission and reception sensitivity and evaluation of the long-term stability with ac transmission in immersion. The main idea of the zero-bias CM...
| Veröffentlicht in: | IEEE transactions on ultrasonics, ferroelectrics, and frequency control. - 1986. - 67(2020), 4 vom: 05. Apr., Seite 879-882 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2020
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| Zugriff auf das übergeordnete Werk: | IEEE transactions on ultrasonics, ferroelectrics, and frequency control |
| Schlagworte: | Journal Article |
| Zusammenfassung: | In this letter, we report the characteristics of zero-bias capacitive micromachined ultrasonic transducers (CMUTs) in various aspects, considering the transmission and reception sensitivity and evaluation of the long-term stability with ac transmission in immersion. The main idea of the zero-bias CMUT implementation is that the charge is injected by the dielectric charging effects in an insulation layer in the pull-in state. The CMUT was fabricated by a local oxidation of silicon (LOCOS) process, and the insulation layer consists of Si3 N4 -SiO2 and SiO2, which have been commonly used in previous studies. A study on the charging effects is reported to quantitatively observe the voltage shift by charge transfer with time dependence at different temperatures and collapsing time dependence. Therefore, we successfully implemented a zero-bias CMUT with a transmission efficiency of 4.62 kPa/V at a center frequency of 7.53 MHz in Si3 N4-SiO2 and a transmission efficiency of 6.78 kPa/V at a center frequency of 7.86 MHz in SiO2 immersion |
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| Beschreibung: | Date Revised 30.03.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1525-8955 |
| DOI: | 10.1109/TUFFC.2019.2950902 |