Immersion lithography is a crucial technology for the exposure process in the production of high-performance very large-scale integrated circuits with line widths greater than 5 nm. Compared to the traditional dry lithography, the immersion liquid fills the space between the last projective objective and the wafer of immersion lithography. The immersion liquid could improve the numerical aperture and exposure resolution due to its high refractive index; however, it poses a challenge to immersion lithography contamination control. To reduce the exposure defects and increase the manufacturing yield, high-precision detection and the control of various contaminants in the immersion system, i.e., achieving the ultra-clean flow control, must be implemented. This paper discusses the development of immersion lithographic equipment by introducing the principles of immersion lithographic technology and comparing dry and immersion lithography. The focus is on the review of the contaminants for the immersion system of immersion lithography, including their generation mechanism, detection methods, and control techniques. It will serve as a theoretical basis for further improving the chip yield after exposure.