SILICON ETCHING TECHNIQUES AND APPLICATION TO MECHANICAL DEVICES

Silicon is being increasingly employed in a variety of new devices, not only because of its well known electrical properties, but also because of its excelent mechanical properties. The microelectronics methodology rapidly appeared as the right answer to the challenge of the batch-fabrication of inexpensive and high-performance sensors and actuators which are easily interfaced with electronics. These mechanical devices often include a flexible beam (or membrane) which can be realized by several selective etching techniques. As an illustration of this methodology, we present the fabrication processes of some silicon mechanical structures which have been used as the sensing parts of a microphone and a magnetic field sensor. On the other hand, we present a simple measurement method of mechanical properties (flexibility, built-in stress). This method has been set for the microphone characterization.