BULK SILICON MICROELECTROMECHANICAL DEVICES FABRICATED FROM COMMERCIAL BONDED AND ETCHED-BACK SILICON-ON-INSULATOR SUBSTRATES

In this work a new and simple technology for the fabrication of bulk s ilicon microelectromechanical devices is presented. The microstructure s are defined in the silicon active layer of commercially available bo nded and etched-back silicon-on-insulator (BESOI) substrates by a sing le photolithographic step and anisotropic dry etching. The thickness o f the structures is only limited by the performance of the dry-etching process. In this work a thickness of 20 mu m is used. Various devices have been fabricated, including electrostatic micromotors, microturbi nes and electrostatically actuated microrelays. An interesting feature of this technology is that the use of BESOI substrates allows the int egration of electronic circuits on the substrate used to fabricate the microelectromechanical devices.