Design And Research Of The Ultrapure Water Treatment System For Immersion Lithography Machine

Integrated circuit is the foundation of manufacturing industry, especially information technology. The ability of lithography technology plays a key role in the development of integrated circuits. Lithography is the use of photochemical reaction characteristics, under ultraviolet light or laser irradiation, copies designed circuit graphics onto silicon wafers. It is one of the most important technologies in the manufacturing industry of integrated circuits. Immersion lithography is based on the dry lithography technology. A layer of immersion liquid that meets the requirements of the optical properties is filled between the surface of the projection lens and the photoresist layer on the silicon wafer. In the integrated circuit industry, as the feature size is reduced, the water quality of ultra pure water used in the production process is higher and higher. The presence of ions, dissolved oxygen, TOC, and particles in the submerged liquid reduces the yield of the integrated circuit, therefore the developing ultrapure water treatment system for immersion lithography machine is particularly important.In this paper, we designed ultrapure water treatment system which used in the immersion lithography. The main works of this paper is shown below.(1) We analysed the water quality index requirements and functional requirements of immersion lithography for ultrapure water treatment. Based on this, the overall design scheme of ultrapure water treatment system was completed. The process principle of the system was designed, and the selection of the corresponding process components was determined according to the requirement of each water quality index.(2) According to the system’s flow and pressure characteristics of the power supply system, we designed and ultimately determined the type and quantity of the centrifugal pump. Based on the system of water quality detection and flow pressure measurement requirements, we determined each kind of sensor selection. Eventually all parts according to its features were divided into sensor module, process module and manual operation module, according to the idea of modular design.(3) We designed the control system of ultrapure water treatment system. With S7-1200 as the lower computer and Advantech IPC as the host computer, PLC finished the data acquisition of the measuring instrument and the order of the actuator. We designed the HMI with real-time monitoring, alarm message, data storage and other functions.(4) The water quality model was constructed by using neural network. We choosed the best network structure according to the error analysis. The prediction of water producing TOC in ultrapure water treatment system was realized by the model. We made implementation of Matlab/Simulink software and monitoring software Kingview communication by using OPC technology. In turn, the predictive value of the Simulink module could be transmitted to the warning information of the configuration interface.