Abstract: Micro/nano fabrication is the dominant factor in increasing the number of components per chip and further shrinking the size of devices. Until now, optical lithography has been the mainstream technology for the integrated circuit industry. For dimensions smaller than 45nm it is still undecided what is the best exposure method. Options include electron beam direct writing and projection, and extreme ultraviolet (EUV) exposure. Recent progress in top-down nano-fabrication processes such as optical, electron beam and EUV lithography, and their applications in manufacturing nano-devices are reviewed.