Object inspection systems and methods

Abstract

Disclosed are systems and methods for object inspection, in particular for inspection of reticles used in a lithography process. The method includes interferometrically combining a reference radiation beam with a probe radiation beam, and storing their complex field images. The complex field image of one object is then compared with that of a reference object to determine the differences. The systems and methods have particular utility in the inspection of a reticle for defects.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of priority to US Provisional Application 61 / 219,158, filed June 22, 2009, which is hereby incorporated by reference in its entirety. technical field [0003] Embodiments of the invention relate generally to object inspection systems and methods, and in particular to object inspection systems and methods in the field of lithography, where the object to be inspected may be, for example, a reticle or other patterning device. Background technique [0004] Photolithography is widely recognized as one of the key steps in the fabrication of integrated circuits (ICs) and other devices and / or structures. However, as the dimensions of features formed using lithography become smaller and smaller, lithography is becoming a more critical factor for achieving miniature ICs or other devices and / or structures to be fabricated. [0005] A lithographic apparatus is a machine that applies a desired p...

AI Technical Summary

Problems solved by technology

Scanning imaging systems, such as Critical Dimension Scanning Electron Microscopy (CDSEM), can be sensitive to small defects (such as defects with feature sizes of 100nm or less, or preferably 20nm or less), but it is a slow process

However, faster optical techniques do not provide very high levels of detection sensitivity

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