Study on ultra-thin NEMS cantilevers - high yield fabrication and size-effect on Young´s modulus of silicon

Presented is a study on ultra-thin silicon cantilevers for nanoelectromechanical systems (NEMS). A single-sided processed fabrication technique is developed for high-yield formation of so thin silicon cantilevers as 12nm, the thinnest single-crystalline-silicon cantilevers reported by now. Attribute to the newly developed fabrication process, during which no any plasma damage is introduced into the silicon thin-film, the ultra-thin cantilevers show ideal mechanical properties including high quality-factor. More important, obvious specimen size effect on Young´s modulus of ultra thin (12-170nm) single-crystalline-silicon film is experimentally obtained by measuring resonant frequency of cantilever-shaped resonators that is constructed with so thin silicon film. Young´s modulus of the cantilevers decreases significantly along with thinning the cantilevers, while surface effect become to play an important role besides bulk effect.