Chromatically corrected objective with specifically structured and arranged dioptric optical elements and projection exposure apparatus including the same

US8345350B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Alexander Epple · Aalen, DE
• Heiko Feldmann · Aalen, DE
• Hans-Juergen Rostalski · Oberkochen, DE

Key dates

• Filing date: Nov 18, 2009
• Grant date: Jan 1, 2013
• Expiry date: May 7, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/706
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An objective having a plurality of optical elements arranged to image a pattern from an object field to an image field at an image-side numerical aperture NA>0.8 with electromagnetic radiation from a wavelength band around a wavelength λ includes a number N of dioptric optical elements, each dioptric optical element i made from a transparent material having a normalized optical dispersionΔni=ni(λ0)−ni(λ0+1 pm)for a wavelength variation of 1 pm from a wavelength λ0. The objective satisfies the relationfor any ray of an axial ray bundle originating from a field point on an optical axis in the object field, where si is a geometrical path length of a ray in an ith dioptric optical element having axial thickness di and the sum extends on all dioptric optical elements of the objective. Where A=0.2 or below, spherochromatism is sufficiently corrected.