Method and apparatus for aerial image improvement in projection lithography using a phase shifting aperture

US6897943B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Uwe Schroeder · Fishkill, US
• Tobias Mono · Dresden, DE

Key dates

• Filing date: Dec 21, 2000
• Grant date: May 24, 2005
• Expiry date: Dec 21, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70191
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A plate 50 for projection lithography comprising a first opaque region 54 located at the center of the plate 50 and a second opaque region 56 formed at the outer edge 52 of the plate. The first and second opaque regions define a light transmissive annular region 58. The annular region 58 comprises a first light transmissive area 60, 62 that imparts a first phase shift to light passing therethrough and a second light transmissive area 64, 66, which imparts a second phase shift to light passing therethrough.