OPTICAL ASSEMBLY

• US 20160091798A1
• Filed: 12/08/2015
• Published: 03/31/2016
• Est. Priority Date: 07/17/2013
• Status: Active Grant

• Current Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Original Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Inventors: Pauls, Walter, Wagner, Hendrik, Wald, Christian, Fritzsche, Steffen, Wabra, Norbert, Bittner, Boris, Schneider, Sonja, Schneider, Ricarda, Ahles, Florian
• Granted Patent: US 9,939,730 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G03F 7/70058 Mask illumination systems
• CPC Class Codes: G03F 7/70258 Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
• CPC Class Codes: G03F 7/7085 Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load

Abstract

An optical assembly, in particular for a lithography system for imaging lithographic micro- or nanostructures, includes at least two optical elements arranged successively in a beam path of the optical assembly, an acquisition device designed to acquire radiation signals from marking elements on or at the at least two optical elements, and a control device coupled to the acquisition device and which is designed to determine the plurality of properties of the optically active surface of the at least two optical elements as a function of the information contained in the radiation signals originating from the marking elements. The disclosure also relates to a method for operating the optical assembly.

Claims

18-1. The optical assembly of claim 19, wherein:

the at least two marking elements comprise a jointly used scattering structure and a jointly used diffractive structure;

each of the at least two marking elements comprises an individually used diffractive structure;

the optical assembly is configured so that radiation signals are transferred from the jointly used scattering structure to the jointly used diffractive structure;

the jointly used diffractive structure is configured to transfer the radiation signals in each case to one of the individually used diffractive structures.

19-1. The optical assembly of claim 1, wherein each of the marking elements comprises a scattering structure and a diffractive structure, the scattering structure is on an underside of the respective optical element, the diffractive structure is on that side of the optically used region of the optical element which is situated opposite the underside, and the optical assembly is configured so that radiation signals are transferred from the scattering structure to the diffractive structure through the optical element.