Photolithography has been the main driving force for the sustained development of semiconductor integrated circuit technology. Its continuously improved resolution and pattern reproduction accuracy have successfully reduced the manufacturing linewidth of integrated circuit from 2~3 μm more than 40 years ago to the current 10~15 nm. During the course of its evolution, many advanced technologies continue to emerge, such as projection lithography, phase-shifting mask, chemically amplified photoresist, and optical proximity effect correction, which timely ensure the advancement of integrated circuit technology along the prediction of the Moore’s law. This paper uses the history of projection lithography as the clue, from 0.25 μm to today’s 5 nm, to analyze the process requirements and process window of each key technology node, including the added technologies and their respective roles,so as to provide a comprehensive presentation of the photolithography process and related technologies with the purpose to give the readers a professional and technical reference.