Illuminating arrangement including a zoom objective incorporating two axicons

US5675401A · kind A · utility

Assignee

• Carl Zeiss Stiftung · DE

Inventors

• Johannes Wangler · Oberkochen, DE
• Gerald Richter · Aachen, DE

Key dates

• Filing date: Jun 15, 1995
• Grant date: Oct 7, 1997
• Expiry date: Jun 15, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70183
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An illumination system for an optical system such as a microlithographic projection exposure system includes a zoom lens 2 for varying the degree of coherence .sigma. and two axicons (22, 23) with an adjustable distance therebetween. The distance can preferably be reduced to zero. The illumination system provides continuous, conventional illumination with a variable degree of coherence .sigma. and annular illumination or multipole illumination with different geometries with low losses of light.