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.