采用几种实用ｉ线抗蚀剂，０４８ＮＡｉ线５×镜头具有０５μｍ线间对成像能力，焦深大于１μｍ。这种镜头与０４０ＮＡ的ｉ线镜头对比，０４０ＮＡ的ｉ线镜头对于≥０７μｍ的线间对图形具有较好的焦深，而０４８ＮＡｉ线镜头对于＜０７μｍ的线间对图形具有较好的焦深，并且可将截止分辨率延伸到０３５μｍ。并探讨了这种镜头吸热效应的相对不灵敏性和这种镜头内Ｈｅ气体的过压作用。假设模拟制作０５μｍ线间对图形的最佳数值孔径在０５～０５５之间，进而提出对０４μｍ线间对图形具有足够焦深，使得ｉ线光刻成为ＤＵＶ光刻技术生产６４ＭＤＲＡＭ器件时代的竞争者。 With several practical i-line resists, 0  48NAi line 5 × lens has a 05μm line-to-line imaging capability with focal depth greater than 1μm. This lens compared with 0  40NA i-line lens, 0  40NA i-line lens for ≥ 0  7μm lines between the graphics have better depth of focus, and 0  48NAi line lens for <0  7μm line Between the graphics has better depth of focus, and the cut-off resolution can be extended to 0  35μm. The relative insensitivity of the endothermic effect of this lens and the over-pressure effect of He gas in this lens were also discussed. Suppose that the optimal numerical aperture of 05μm line to the figure is between 05 ~ 055 by simulation, and then it is proposed to have enough depth of focus on the 04μm lines to make the i line photolithography become DUV lithography Technology to produce 64MDRAM device era competitors.