Design method of catadioptric deep ultraviolet lithography objective lens system

Abstract

The invention discloses a design method of a catadioptric deep ultraviolet lithography objective lens system. According to the method, the initial structure is designed through a grouping compounding and iterative design method, so that the initial structure of the catadioptric photoetching objective lens system is quickly and efficiently obtained. The objective lens system comprises three subsystems: a first lens group G1, a second lens group G2 and a third lens group G3. The design method of the objective lens system comprises the following steps: designing initial structures of the G1 and G3 according to design requirements; setting the image plane of G1 as the object plane of G2, and the image plane of G2 as the object plane of G3; and setting G2, including two oppositely arranged reflectors, calculating a spherical initial structure of the G2 through matrix optics, and performing grouping compounding and iterative fitting design on the spherical initial structure of the G2 to complete the design of the initial structure of the lens group G2. Through subsequent optimization design, the design of the high-performance catadioptric deep ultraviolet lithography objective lens system is completed, and the overall design efficiency of the catadioptric deep ultraviolet lithography objective lens system is improved.

Description

technical field [0001] The invention relates to the technical field of optical design, in particular to a design method for a catadioptric deep ultraviolet lithography objective lens system. Background technique [0002] The photolithography machine is the core equipment for the manufacture of large-scale integrated circuits. It can project the IC pattern on the mask onto the photoresist on the surface of the silicon wafer through exposure, and then transfer the projected pattern to the silicon wafer through developing, etching and other technologies. face. Among the many components of a lithography machine, the projection lithography objective lens system is one of its core components. [0003] The theoretical resolution of the lithography system can be calculated by R=k1λ / NA, where k1 is the process factor, which is related to the process parameters of the lithography system, λ is the exposure wavelength of the system, and NA is the image square numerical aperture of the ...

AI Technical Summary

Problems solved by technology

The structure of the DUV lithography objective lens system is complex, and the initial structure design is difficult. Patent CN 105652606 A discloses a design method of catadioptric deep ultraviolet lithography objective lens, but this method only applies the concept of grouping design to catadioptric DUV lithography In the design of the initial structure of the objective lens system

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