Application Of Negative-pressure Collecting Structure For The Flow Field’s Non-contact Seal

Immersion lithography is the only large-scale application for lithography technology under 45nm IC production line currently. Dynamic sealing device is the core component of immersion lithography machine, placed between the projection lens and silicon wafer, and keep the gap of 0.1mm. Gap flow field is formed between the dynamic sealing device and wafer, no liquid loss has to be ensured by the collecting structure during the scanning process. Optimizing the collecting structure of dynamic sealing device, and realization of the non-contact sealing for the immersion liquid are the key problems, which immersion lithography technology confronts with.In this thesis, the collecting structure of dynamic sealing device is studied, the main contents are briefly stated as the followings:Firstly, a numerical model is built to simulate the internal flow field of the dynamic sealing device’s collecting structure.The law of the gap flow field sealing performance is obtained by numerical simulation, considering different parameters of the pore in collecting structure, different fluid injecting velocity and liquid collecting pressure.Secondly, an equivalent model simulating the dynamic sealing device is designed and also the test-bench system. The testing models with different collecting structures are investigated. Comparing experimental results with simulation results, the effect of collecting pores on the non-contact sealing is analysed and the configuration model that describes collecting structure’s parameters is obtained.Finally, a dynamic sealing device for immersion lithography machine is designed based on the research result, implementing the concept of negative-pressure collecting for non-contact sealing.Through the numerical simulation and experiment method, the critical scanning velocity under different working conditions are obtained. After performance testing, the dynamic sealing ability of sealing device is proved, with the critical velocity increasing by 50%. It proves that the research result on the collecting structures with varing pores parameters is correct, and it presents support for the design and optimization of dynamic sealing device.