Patent ID: 6307682
Filing Date: 2001-10-23
Classification: G02B,G03F

Abstract:
An illumination system for photolithography, comprising:an illumination source and an optical integrator that together produce a plurality of incident source images;a condenser that receives a plurality of incident beams from the plurality of incident source images and forms an illumination field at an illumination plane using the incident beams, the condenser including a Zoom Array Integrator (ZAI) having fixed and movable lens components arranged to controllably vary a size of the illumination field throughout a zoom range of the ZAI and to maintain telecentric illumination at a substantially fixed numerical aperture at the illumination plane throughout the zoom range, whereby the illumination field is scattered by an optical element and then telecentrically imaged to a reticle with a substantially fixed reticle numerical aperture at the reticle throughout the zoom range.