Illumination system of a microlithographic projection exposure apparatus

US9213244B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Michael Patra · Oberkochen, DE
• Markus Schwab · Aalen, DE

Key dates

• Filing date: Dec 27, 2012
• Grant date: Dec 15, 2015
• Expiry date: Feb 7, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70116
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An illumination system of a microlithographic projection exposure apparatus includes an optical integrator that includes an array of optical raster elements. A condenser superimposes the light beams associated with the optical raster elements in a common field plane. A modulator modifies a field dependency of an angular irradiance distribution in an illuminated field. Units of the modulator are associated with one of the light beams and are arranged at a position in front of the condenser such that only the associated light beam impinges on a single modulator unit. The units are configured to variably redistribute, without blocking any light, a spatial and/or an angular irradiance distribution of the associated light beams. A control device controls the modulator units if it receives an input command that the field dependency of the angular irradiance distribution in the mask plane shall be modified.