Lithographic objective having a first lens group including only lenses having a positive refractive power

US6788387B2 · kind B2 · utility

Assignee

• Carl Zeiss Semiconductor Manufacturing Technologies AG · DE

Inventors

• Karl-Heinz Schuster · Oberkochen, DE
• Alexander Epple · Aalen, DE

Key dates

• Filing date: Dec 26, 2001
• Grant date: Sep 7, 2004
• Expiry date: Apr 4, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B27/0043
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A projection objective includes a first lens group (G1) of positive refractive power, a second lens group (G2) of negative refractive power and at least one further lens group of positive refractive power in which a diaphragm is mounted. The first lens group (G1) includes exclusively lenses of positive refractive power. The number of lenses of positive refractive power (L101 to L103; L201, L202) of the first lens group (G1) is less than the number of lenses of positive refractive power (L116 to L119; L215 to L217) which are mounted forward of the diaphragm of the further lens group (G5).