High NA Annular Field Catoptric Projection Optics using Zernike Polynomial Mirror Surfaces
AssigneeNikon Corporation
InventorsDavid M. Williamson, Daniel G. Smith
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Abstract
Optical structure and design concepts are provided, using a Y-Zernike polynomial, and by which optical components, optical components and optical structures, can be designed and produced, to image at extreme ultraviolet (EUV) wavelengths, at a relatively high NA (e.g. 0.35), with a relatively large field of view (e.g. 26×2 mm). Moreover, an optical structure produced according to the principles of the present invention has a small amount of asymmetry, which enables the components of the optical structure to be manufactured with current manufacturing techniques.
Claims20
An optical mirror component for a projection optics system, the optical mirror component comprising an optical surface that is described by a Y-Zernike polynomial.
An optical projection structure for a projection optics system, the optical projection structure comprising one or more projection optics, at least one of which has an optical surface described by a Y-Zernike polynomial.
A method of designing an optical structure, comprising
- a. providing a rotationally symmetric aspheric optical structure design,
- b. electronically converting the optical surface(s) of one or more of the optical components of the optical structure to a Y-Zernike description,
- c. providing a plurality of field points that are out of a plane of symmetry of the optical structure, and
- d. electronically optimizing the description of the one or more components at the plurality of field points.
Dependencies are inferred from the claim text.