Light mode converter in immersion lithography lighting system

The lighting mode convertor module in NA1.35 immersion lithography lighting system design has been designed and tested. The lighting mode convertor system can be realized by using diffractive optical element(DOE) in the design and analysis, including the traditional lighting mode, diode lighting mode and quadrupole lighting models. And then different lighting models of diffractive optical elements for the design results were presented. The results were simulated and the experimental results were analyzed, which proved the feasibility of the design. The research results show that when the input optical field is divided with the number of array of 2020 units, the diode lighting and quadrupole lighting models of diffractive optical elements are with numbers of 32 steps, the traditional lighting mode of 128 steps, the uniformity of diffractive optical elements as lighting mode converters and the diffraction efficiency are able to meet the design requirements. From the basis principle, the experimental validation of diffractive optical elements correctness and feasibility of the laser mode converter design can meet the requirements. The results can be applied to the immersion lithography lighting mode convertors in the immersion lithography lighting system structure, which have the great certain theoretical value and engineering significance.