Mikromechanische Ultraschallwandler aus Silizium

This paper discusses basic issues of micromachined ultrasonic transducers, including their design and fabrication. First, the acoustic fundamentals of ultrasonic transducers are introduced, and relevant simulation methods are illustrated. Following these topics, important aspects of silicon micromachining are presented. Based on this knowledge, two distinctive micromachining processes for transducer fabrication are proposed. One of them, the bulk process, has been proved to be successful, whereas for the second one, a surface process, some improvements are still needed. Besides these works, an innovative direct bonding technology is also developed. This technology constitutes the basis of the bulk process. Of course, it can also be used for the packaging of other MEMS devices.