Projection objective of a microlithographic projection exposure apparatus

US9372411B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Johannes Zellner · Aalen, DE
• Boris Bittner · Roth, DE
• Norbert Wabra · Werneck, DE
• Martin von Hodenberg · Oberkochen, DE
• Sonja Schneider · Lehrberg, DE
• Ricarda Schoemer · Zusmarshausen, DE
• Arne Schob · Jena, DE
• Guenter Rudolph · Jena, DE
• Alexander Gratzke · Jena, DE
• Bryce Anton Moffat · Jena, DE

Key dates

• Filing date: Mar 6, 2014
• Grant date: Jun 21, 2016
• Expiry date: Jan 31, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S5/4025
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A projection objective of a microlithographic projection exposure apparatus includes a wavefront correction device including a refractive optical element that has two opposite optical surfaces, through which projection light passes, and a circumferential rim surface extending between the two optical surfaces. A first and a second optical system are configured to direct first and second heating light to different portions of the rim surface such that at least a portion of the first and second heating light enters the refractive optical element. A temperature distribution caused by a partial absorption of the heating light results in a refractive index distribution inside the refractive optical element that corrects a wavefront error. At least the first optical system includes a focusing optical element that focuses the first heating light in a focal area such that the first heating light emerging from the focal area impinges on the rim surface.