The Design And Implementation Of The ArF Laser Beam Delivery

ArF laser beam delivery is one of the key components which connect ArF laser source and lithography equipment. ArF laser's beam shape, directionality and micro positive pressure control system are key indicators of the beam delivery. In this thesis, according to the key indicators, we put forward appropriate solutions,and we separated the beam delivery into three units: Optical shaping, optical adjusting unit and optical purification unit. Then we completed the computational simulation and testing.The impact which lens parameters and distance have on the spot shape is studied in this thesis, lens model is established for ray-tracing, analyzed if a spot in the ultimate size meets the requirements. Optical shaping unit uses two cylindrical prisms which are perpendicular and a corresponding lens to achieve the goal of optical shaping.This thesis analyzed the relationship between the requirements and the optical adjustment device-differential head's range and precision. We proposed the solution which using micrometer heads and disk spring to adjust the orientation of lens to meet the demand.In this thesis, the factors which affect the differential pressure of the chamber is analyzed, the relationship between the differential pressure change and the environment pressure change is studied, the relationship between the differential pressure change and the capillary's structural parameters(inside diameter and length) is established. Capillary is utilized to achieve slightly positive pressure control. A capillary is placed at the inlet of the chamber, and a throttle is placed at the outlet of the chamber. When the outside air pressure fluctuations, due capillary's throttling and pressure maintaining characteristics, the slightly positive pressure state can be kept stable.Based on the above solutions and principle, we discussed the detailed design of each unit's mechanical structure and the test methods. We established a set of ArF laser beam delivery, We achieved the requirements which output beam spot size is 20 mm ± 3mm, 20 mm ± 3mm; output beam direction adjustment range: +/-5mrad, adjusting accuracy: 0.5mrad; output beam position adjusting range: +/-5mm, adjusting accuracy: 0.5mm; the difference between gas supply and the outlet pressure is 100-1000 Pa ± 10%, implement micro positive pressure state in the beam delivery.