ULTRASONIC TRANSDUCER AND METHOD FOR MAKING SAME

摘要

An ultrasonic transducer (38) including a 0.1-0.5 mu m-thick silicon nitride membrane (4a) with an intrinsic mechanical stress of 100 MPa to 1.3 GPa, and a fixed electrode (15) made of a non-metallic rigid material and provided with a plurality of holes (25) with a small average diameter, said fixed electrode defining with said membrane an inner space 1-5 mu m thick. A method for making said ultrasonic transducer is also disclosed.