Experimental immersed projective lithography objective lens

Abstract

The invention discloses an experimental immersed projective lithography objective lens, wherein a dioptric lens set consisting of a Schwarzschild refracting-reflecting structure with a larger relative aperture and three pieces of meniscus lenses is adopted, so that the numerical aperture of a system can be improved to 1.20, and the lithography resolution ratio can be improved; the negative petzval field curvature generated by the Schwarzschild refracting-reflecting structure is balanced by the meniscus lenses, so that an image field can be flattened and an image space view field can be enlarged; the high-level aperture positive spherical aberration and the residual negative coma aberration remained by an eighth planoconvex lens L8 correction system with a 10-order aspheric surface are adopted, so that the numerical aperture can be improved, and the imaging quality of a lithography system can be guaranteed; and the whole set of system only uses 8 lenses, so that the structure is simple and compact, the imaging quality can be guaranteed, and the production cost can be reduced.

Description

technical field [0001] The invention relates to the technical field of high-resolution projection lithography objective lens, in particular to an experimental deep ultraviolet immersion lithography objective lens. Background technique [0002] Before the successful development of complex and expensive industrial immersion ArF lithography equipment, the research and development of many key technologies needs to be carried out on micro-miniature experimental prototypes, so as to shorten the research and development cycle and cost, and more effectively support industrial lithography machine development. [0003] The ultra-high resolution experimental immersion lithography objective lens is a key component in the immersion lithography experimental platform. At present, Nikon in Japan, Corning in the United States and other companies have disclosed experimental lithography objectives, including: small field of view total refraction projection lithography objectives, Schwarzschil...

AI Technical Summary

Problems solved by technology

[0004] Among them, the total refraction lithography projection objective lens made of fused silica material is extremely sensitive to the line width of the light source; the high numerical aperture total refraction lithography projection objective lens made of fused silica material and calcium fluoride material has a complex structure. In order to ensure its working bandwidth, Using two kinds of materials to achromatize, resulting in more lenses, longer total system length and higher cost

The existing Newtonian catadioptric projection lithography objective lens has a relatively large working bandwidth, but its central obscuration is too large, resulting in a significant decrease in the low-frequency contrast of the objective image.

Existing Schwarzschild catadioptric projection lithography objectives such as figure 1 As shown, it uses fewer lenses, has a certain working bandwidth, and a smaller central obscuration, but the numerical aperture of the lithography projection objective lens is only between 0.5 and 1.05, and the resolution is limited

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