Illumination optical system used for micro-photoetching

Abstract

The invention provides an illumination optical system for microlithography. The system comprises light sources, a quartz rod, a relay lens and an illumination field, wherein the quartz rod is positioned on a light path of the light sources; light given out by the light sources enters from an incident end of the quartz rod and is emitted from an emergent end; the relay lens is positioned on an emergent light path at the emergent end of the quartz rod; the illumination field is positioned on an outlet light path of the relay lens; and the system also comprises a step motor which drives the quartz rod to rotate at an angle of 180 degrees. The illumination system for microlithography can achieve the aim of changing related factors by a simple method or achieve the aims of simplifying the structure and reducing the cost by simplifying the design complexity of a zoom lens.

Description

technical field [0001] The invention relates to the field of microlithography, and more specifically, relates to a set of illumination optical systems in microlithography equipment. Background technique [0002] In the existing photolithography method, the optical system using high-pressure mercury lamp illumination mainly exposes g (436nm) h (405nm) i (365nm) three lines, and obtains a certain photoresist pattern on the silicon wafer coated with photoresist, and then The same photoresist pattern is obtained on the silicon wafer through etching and other steps. [0003] According to different exposure requirements, different exposure fields of view, numerical apertures or coherence factors are sometimes required on the silicon wafer. [0004] The existing technology mainly replaces the condenser lens or relay lens of the illumination system with a zoom lens group, and different focal lengths correspond to different exposure fields of view, numerical apertures or coherence f...

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