Deep dry etching of SOI for silicon micromachined structures

This paper reports on preliminary results in the production of novel silicon micromachined structures in thick Silicon On Insulator (SOI) at DERA (Malvern). Significant interest in SOI for micromachining has existed for several years, however, until recently the quality of SOI material was not sufficiently high to make it a viable alternative to mainstream bulk silicon technology. Specially designed thick SOI layers have been deep dry etched and structures released to demonstrate the applicability of the material and etch technique to micromachining. An exciting combination of the advantages of both surface and bulk micromachining is offered by SOI. The process used is fully compatible with CMOS and it is thought that the SOI material will become of major importance in many areas of micromachining, particularly micro-inertial components