Wet release technology for bulk-silicon resonators fabrication on silicon-on-insulator substrate

Stiction occurring in the release phase is a severe problem in many MEMS devices. This phenomenon is due to capillary forces and solid–solid adhesion, which develops during drying after a wet etching process. The possibilities and the limits of the use of a solvent with low surface tension is investigated in the case of MEMS resonators fabricated on silicon-on-insulator substrate. It is shown as in this case it is possible to obtain stiction-free structures without the necessity of more expensive and complicated techniques such as supercritical drying or hydrofluoric acid (HF) vapor etching. The fabrication and design limit of this solution are also investigated.