Study on Temperature Control Model and Algorithm for the Discharge Cavity of Excimer Laser

ABSTRACT: Aiming at the characteristics of multiple time delays and multiple disturbances in the long-distance indirect water-cooling temperature control loop of the ArF excimer laser discharge cavity with a dual-cavity structure, the foundation of a double closed-loop control structure composed of the discharge cavity temperature and the remote cooling water temperature is established In the above, the parallel cascade control structure of the cooling water flow of the proximal discharge cavity and the discharge cavity temperature is introduced, forming a multi-closed-loop control model of the discharge cavity temperature of the ArF excimer laser; a dual-input dual-output nonlinear PI algorithm is established to further increase the temperature convergence speed and steady-state accuracy of flow control; transfer function analysis and comparative experiments show that the system has better decoupling effect on multiple time delays, better suppression and adaptability to multiple disturbances, and has been successful Applied to the temperature control of the discharge cavity of the 193nm dual-cavity ArF excimer laser, it realizes the rapid convergence of the discharge cavity temperature and the stability of ±0.1℃, as well as a faster flow rate optimization speed and adaptability to pressure fluctuations; The method is also applicable to other complex objects that use liquid circulation to control temperature.