Focusing and leveling measuring system and its measuring method

Abstract

The invention discloses a focusing leveling measuring system and a measuring method thereof. The measuring system comprises an object grating, a first image-forming system, a second image-forming system, a detecting grating, and a detecting die block, wherein the first image-forming system can lead the object grating to image on a tested object to form a first grating image through laser illuminating, and the second image-forming system can lead the first grating image to image on the detecting grating to form a first detecting image, and the first detecting image and the detecting grating are overlapped to form a first Moire fringe which is detected by the detecting die block, position information of the detecting die block is fixed, and position information of the tested object is expressed on the first Moire fringe relative to the position information of the detecting die block.

Description

technical field [0001] The invention relates to an optical electromechanical device, in particular to a focusing and leveling measuring system and a measuring method thereof in a projection photolithography system. Background technique [0002] Photolithography device (lithography machine) is one of the important equipment for the production of large-scale integrated circuits. The photolithography machine can transfer the pattern on the mask plate to the object to be processed (such as silicon wafer, etc.) in a certain proportion through the exposure device. Silicon wafers here generally refer to all exposed objects, including substrates, coatings and photoresists. During the exposure process, it is necessary to keep the corresponding surface of the processing object (such as a silicon wafer) within the focal depth range of the exposure device. For this reason, the lithography machine adopts a focusing and leveling measurement system for measuring surface position informat...

AI Technical Summary

Problems solved by technology

[0005] In addition, due to its own flaws in principle, the photoelectric detection method based on slit and four-quadrant detectors (US Patent US 6765647B1) not only has poor system stability, but also has low measurement accuracy

If the photoelectric detection method based on slits and four-quadrant detectors (US Patent US 6765647B1) achieves the same accuracy as other focusing and leveling measurement systems, the structure of the focusing and leveling measurement system will become quite complicated

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