A correction method for self-alignment process window of dark field defect detection equipment

Abstract

The invention provides a correction method for a self-aligned process window of dark field defect detection equipment. The method comprises the following steps of: (S1) providing a test wafer which comprises test areas with different functional film thicknesses and areas; (S2) testing different test areas and collecting different reflected light signal intensities; (S3) fitting the reflected light signal intensities Y to obtain a fitting formula Y=alphax<n>+betay<n>+gamma; and (S4) calculating the required self-aligned light intensity value by combining the thicknesses and the areas of the functional films in actual technology production according to the fitting formula to achieve parameter adjustment on the dark field defect detection equipment. The fitting formula is obtained through a multi-observation point test on the test areas with different functional film thicknesses and areas, and the required self-aligned light intensity value can be calculated, so that the self-alignment failure caused by over-dark or over-bright functional films is effectively avoided; parameters of the dark field defect detection equipment can be adjusted in real time; and the condition that the light intensity value of the dark field defect detection equipment meets an effective range of self-alignment correction is ensured.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for correcting a self-alignment process window of a dark field defect detection device. Background technique [0002] The dark field defect detection equipment needs to perform real-time self-alignment correction during the scanning process to adjust the distance between the wafer and the light source to achieve the best self-alignment effect. With the development of integrated circuit technology and the scaling down of key dimensions, as well as the increase in the complexity of semiconductor manufacturing, the materials and thickness of the films that need to be filled also have more diverse changes. [0003] The self-alignment system of dark-field defect scanning equipment usually uses a single light source for self-alignment calibration for all thin-film materials, and the following defects will obviously appear: for particularly dark thin-film ma...

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Problems solved by technology

[0006] The present invention is aimed at the self-alignment system of the traditional dark field defect scanning equipment in the prior art, which is very prone to self-alignment failure on the surface of a particularly dark or bright film material, and how to determine the self-alignment system of the machine There is currently no clear method for self-alignment correction on the wafer surface of which brightness

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