Interferometric measuring device and projection exposure installation comprising such measuring device

Abstract

A measuring device for interferometric measurement of an optical imaging system that is provided for projecting a useful pattern, provided on a mask, into the image plane of the imaging system, includes a wavefront source for generating at least one wavefront traversing the imaging system; a diffraction grating, arrangeable downstream of the imaging system, for interacting with the wavefront reshaped by the imaging system; and a spatially resolving detector, assigned to the diffraction grating, for acquiring interferometric information. The wavefront source has at least one measuring pattern that is formed on the mask in addition to the useful pattern. The useful pattern may represent the structure of a layer of a semiconductor component in a specific fabrication step. The measuring pattern may be formed as a coherence-forming structure periodic in one or two dimensions.

Description

[0001] This application is a divisional of application Ser. No. 10 / 964,868 filed Oct. 15, 2004, the entire disclosure of which is incorporated herein by reference. Priority is claimed from German Patent Application 102 17 242.0 filed Apr. 15, 2002. The disclosure of International Application PCT / EP03 / 03566 is incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates to a measuring device for interferometric measurement of an optical imaging system and to a microlithographic projection exposure installation in which such a measuring device is integrated. [0004] 2. Discussion of the Related Art [0005] Higher and higher requirements are being placed on the imaging quality of optical imaging systems. One example of this is projection objectives for microlithographic production of semiconductor components and other finely structured components which are intended to produce structures in the sub-micrometer range largely free...

AI Technical Summary

Benefits of technology

This solution enables rapid and fault-free measurements of projection objectives during operation, reducing machine downtimes and increasing productivity by integrating the measurement structures directly into the reticle used for chip production, allowing for timely detection and correction of imaging quality issues.

Problems solved by technology

Since, on account of the complicated optical structure, it is as a rule impossible to derive the optical properties of the objectives from theoretical calculations, the optical properties have to be measured reliably, at least during the assembly and the adjustment of the optical imaging systems.

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