This paper presents a process for the fabrication of vacuum-sealed capacitive micromachined ultrasonic transducer (CMUT) arrays using glass reflow and anodic bonding techniques. The silicon through-wafer interconnects have been investigated by glass reflow process. Then, the patterned silicon-glass reflow wafer is anodically bonded to an SOI (silicon-on-insulator) wafer for the fabrication of CMUT devices. The CMUT 5 x 5 array has been successfully fabricated. The resonant frequency of the CMUT array with a one-cell radius of 100 µm and sensing gap of 3.2 um (distance between top and bottom electrodes) is observed at 2.83 MHz. The Q factor is approximately 1300 at vacuum chamber pressure of 0.01 Pa.
Journal: TechConnect Briefs
Volume: 4, Advanced Manufacturing, Electronics and Microsystems: TechConnect Briefs 2016
Published: May 22, 2016
Pages: 91 - 95
Industry sector: Sensors, MEMS, Electronics
Topics: MEMS & NEMS Devices, Modeling & Applications