Optical Design For Arf Immersion Lithography Progection Lens

At present, industrially developed countries on behalf of Japan and Holland areable to produce lithography machine with exposure node downward25nm. The numberof the projection lens component, core component of lithography machine, is more than20.And the wave aberration excels1nm.Lithography machine have made greatcontribution to the semi-conductor industry of our nation. The ArF Immersed ProjectionLithography Machine is the most precisely designed and structurally complicatedoptical system, researches with respect to it are involved with various areas. As thecentral pivot of lithographic machine, the lithographic projection lens’s design isreferred to whole composition of lithography machine. For this reason, it is necessary toset about optimal design and imaging quality analysis of the ArF Immersed ProjectionLithography Machine with professional software to reduce dispensable design fault andprolonged design circle.This article is aimed at the optical system design facing60nm exposure node of theArF Immersed Projection Lithography Machine. In consideration of factors includingArF exposure light source’s feature, lithographic projection lens’s structure, resolutionbooster technology, optical material, coating film and component processing et al, weget an immersed lithographic projection lens with numerical aperture of1.2andworking wavelength of193nm.Besides that, we have made the tolerance analysisfocused on key components of lithographic projection lens, by analyzing what tolerancehave the biggest impact on the RMS of the optical system, the imaging quality andproper tolerance distribution are both insured.In terms of the optical design of ArF Immersed Projection Lithography Machine,this article shows main content as following:(1) Design Axiom Need vector analysis requirements are elicited through studyingimaging character of the optical system under large numerical aperture and analyzingfacula tolerance caused by vector and scalar diffraction with professional software. Onthe basis of generalized pupil function concept, evaluation methods about the imagequality of large numerical aperture projection lens are explored, and assessment methods applied to lithographic projection lens are obtained.(2) Optical Design After comprehensive analysis containing light beam character ofexcimer laser, optical materials applied to ArF wave band and its transmittance andoptical structure specificity of the refraction-reflex lithographic projection lens, the ArFImmersed Refraction-Reflex Lithography Projection Lens with a1.2numerical aperturewas designed.(3) Tolerance Analysis We proceeded the tolerance analysis of key components ofthe designed lithographic projection lens, by analyzing what tolerance have the biggestimpact on imaging quality, tolerance sensitivity of key components was gained.The simulation result indicates that the exposure node of the designed ArFImmersed Lithographic Projection Lens can reach to60nm, which fit the designrequirements.