Projection exposure methods and systems

US8917379B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventor

• Paul Graeupner · Aalen, DE

Key dates

• Filing date: Jun 12, 2009
• Grant date: Dec 23, 2014
• Expiry date: Apr 20, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70891
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Projection exposure methods, systems, sub-systems and components are disclosed. Methods can include performing a first exposure to image a first sub-pattern of the pattern, where the first sub-pattern includes a plurality of first features extending in a first direction and spaced apart essentially periodically at a predominant periodicity length P in a second direction perpendicular to the first direction. The first exposure can be performed using a multipolar illumination mode that includes at least one substantially dipolar intensity distribution having two illumination poles positioned on a pole orientation axis substantially parallel to the second direction and spaced apart from each other. The poles of the dipolar intensity distribution can each have an azimuthal width defined by a pole angle θ, and a pole area APOLE according to: 0.6<APOLE/AOPT<1.1, where AOPT is a pole area according to: AOPT=θ−sin(θ), with cos(θ/2)=λ/(2*P*NA), where λ is a nominal operation wavelength of radiation used for the first exposure and NA is an image-side numerical aperture of a projection optical system used for the first exposure.