Position measuring device and position measuring method

Abstract

The invention provides a position measuring device and a position measuring method. The position measuring device comprises a light source module, an illumination module, a projection aperture, a projection raster, a projection imaging module, a detection imaging module, a detection raster and a detection module, wherein after light emitted by the light source module passes through the illumination module, the projection aperture and the projection raster, the projection raster is imaged on an object to be measured by the projection imaging module so as to form a raster image; and the raster image is imaged to the detection raster so as to form a detection image by the detection imaging module; the detection image and the detection raster are overlaid to form a Moire fringe; the Moire fringe is detected by the detection module; and the projection raster is a rough raster. The invention has simple structure and higher sensitivity and measures in a direct way.

Description

technical field [0001] The invention relates to an opto-mechanical device, in particular to a position measuring device and method. Background technique [0002] The lithography apparatus is one of the important equipments for the production of large-scale integrated circuits. The lithography machine can transfer the pattern on the mask to the object to be processed (such as silicon wafer, etc.) in a certain proportion through the exposure device. Silicon wafer here refers 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, etc.) within the focal depth range of the exposure device. To this end, the lithography machine adopts a focusing and leveling measurement system for measuring the surface position information of the processed object (such as a silicon wafer, etc.). The focusing and leveling measurement system can work t...

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Problems solved by technology

[0005] Another example is the focusing and leveling measurement system in a lithography machine in a published patent (patent number: CN20071017196.5), which is another application of the object position measurement system, although the method provided by this patent is relatively The stability of the method has been improved, but in this patent, there are still the following disadvantages: the projection and detection grating adopts a coded grating detection scheme, which leads to a complex overall structure; in addition, because the method does not use the corresponding subdivision technology, Therefore, the measurement sensitivity of the measurement system is not high

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