Tailoring diffraction-induced light distribution toward controllable fabrication of suspended C-MEMS

A simple and controllable method is proposed to fabricate suspended three-dimensional carbon microelectromechanical systems (C-MEMS) structures by tailoring diffraction-induced light distribution in photolithography process. An optical model is set up and the corresponding affecting parameters are analyzed to interpret and predict the formation of suspended structures based on Fresnel diffraction theory. It is identified that mask pattern dimensions, gap distance between the photomask and photoresist, and the exposure time are critical to the final suspended structures, which have also been verified through experimental demonstrations. The fabricated biocompatible suspended C-MEMS structures could find wide applications in electrochemical and biological areas. (C) 2012 Optical Society of America