Manufacturability of Highly Densed Arrays of SC 20% Doped ALN Monolithic PMUT

The focus of this paper is to present a comparative study for highly dense arrays of Piezoelectric Micromachined Ultrasonic Transducers (PMUT), manufactured using a Aluminium Nitride (AlN) and emerging Aluminium Scandium Nitride (Al20%ScN) thin films. Monolithic PMUT manufacturing method is used to fabricate the devices. A 100 × 100um array of PMUT, each unit cell has 40μm cavity and the pitch is 57μm, is designed as a test vehicle to monitor the process performance of these two films.