Microlithographic reduction projection catadioptric objective

US7218445B2 · kind B2 · utility

Assignee

• Carl Zeiss Stiftung · DE

Inventors

• David Shafer · Fairfield, US
• Russell Hudyma · San Ramon, US
• Wilhelm Ulrich · Aalen, DE

Key dates

• Filing date: May 13, 2003
• Grant date: May 15, 2007
• Expiry date: May 13, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70358
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A photolithographic reduction projection catadioptric objective includes a first optical group having an even number of at least four mirrors and having a positive overall magnifying power, and a second substantially refractive optical group more image forward than the first optical group having a number of lenses. The second optical group has a negative overall magnifying power for providing image reduction. The first optical group provides compensative aberrative correction for the second optical group. The objective forms an image with a numerical aperture of at least substantially 0.65, and preferably greater than 0.70 or still more preferably greater than 0.75.