P4M-1 Design, Fabrication and Characterisation of Capacitive Micro-Machined Ultrasonic Transducers Based on a 2D-Like Architecture

In this work, we report on the design and test of a cMUT structure based on a thin silicon membrane shaped in order to comply our modeling assumptions, i.e. long 2D-like cMUT cells able to operate conformably to the simulated operation of an actual 2D structure. The device is designed to operate at a minimum of 6 MHz in air and to exhibit an operation bandwidth larger than 100% in water. The silicon membrane is about 1.5 mum thick and the leading lateral dimension is 42 mum. Tests in water are also performed, pointing out numerous parasitic contributions on the measured admittances and time-resolved signals.