Abstract
This work presents the fabrication process of anodically bonded 192+192 2D row-column addressed (RCA) capacitive micromachined ultrasonic transducer (CMUT) arrays. Four large 2.1 by 2.1 cm2 arrays with a resonance frequency of 7.5 MHz in water and ⋋/2 element pitch at 95 µm are shown successfully fabricated. The arrays exhibit a 100% bond yield by anodically bonding an SOI wafer to a borosilicate glass wafer structured with CMUT cavities. A silicon nitride layer has been used at the wafer bonding interface to insulate the top and bottom electrodes for high voltage operation to at least ±200V DC bias. Electrical measurements have been performed on 192+192 RCA arrays and smaller 16+16 RCA arrays. These showed a resonance frequency of approximately 18 MHz in air at a bias of -200 V, corresponding to 80% of the pull-in voltage and 50 mV AC, with a coupling coefficient of 26.8 %.
Original language | English |
---|---|
Title of host publication | 2020 IEEE International Ultrasonics Symposium (IUS) |
Number of pages | 4 |
Publisher | IEEE |
Publication date | 2020 |
ISBN (Print) | 978-1-7281-5449-7 |
ISBN (Electronic) | 978-1-7281-5448-0 |
DOIs | |
Publication status | Published - 2020 |
Event | 2020 IEEE International Ultrasonics Symposium - Virtual symposium, Las Vegas, United States Duration: 6 Sept 2020 → 11 Sept 2020 https://2020.ieee-ius.org/ |
Conference
Conference | 2020 IEEE International Ultrasonics Symposium |
---|---|
Location | Virtual symposium |
Country/Territory | United States |
City | Las Vegas |
Period | 06/09/2020 → 11/09/2020 |
Internet address |