Abstract: Immersion lithography machine is the only new equipment used at present for the IC production line below 45 nm. Immersion control system is one of the key components of immersion lithography machine, and its main function is to provide a highly clean and stable immersion liquid between the last one projection lens and wafer. As the refraction index of the liquid is higher than air, the resolution of lithography can be improved. In this paper, the technology background, composition and characteristics of immersion control system are introduced. The foreign research results of key technologies about liquid fill method, dynamic seal, flow detection and control, exposure thermal effect and air bubble control are discussed, and the progress of domestic research on the immersion control system is given. Finally, it is pointed out that there are some challenges and key technologies of immersion control system necessarily to be solved in future. The immersion control system will continue to play an important role in the developing process of immersion lithography machine.

Key words: Immersion control system, Immersion fluid, Immersion lithography machine