Method for improving alignment signal processing precision based on self-adapting correction treatment

Abstract

The invention discloses a method for improving alignment signal processing accuracy based on adaptive correction processing. The method uses an elliptical side lobe filter to achieve better filtering effect; and uses a method for checking whether the alignment position is within the capture range , adaptively update the scan center and scan range, improve the adaptability of the alignment scan to the size of the spatial image, thereby improving the repeatability and scanning efficiency of the alignment scan; provide adaptive update threshold constant value and threshold filtering The processing method improves the adaptability of the alignment scan and the accuracy of the alignment scan.

Description

technical field [0001] The invention relates to a method for improving alignment signal processing accuracy based on adaptive correction processing, in particular to a method for improving alignment signal processing accuracy based on adaptive correction processing in an alignment system of a lithography equipment. Background technique [0002] In industrial devices, due to the need for high precision and high productivity, a large number of detection devices and control systems for high-speed real-time measurement, signal sampling, data acquisition, data exchange, communication transmission and signal processing are distributed. These systems require us to use various methods to realize the control of detection, signal sampling control, data acquisition control, data exchange control, data transmission communication and signal processing. Devices that require detection signal processing and control include: integrated circuit manufacturing lithography equipment, flat panel ...

AI Technical Summary

Problems solved by technology

[0005] In some cases, the maximum normalized optical information value of a single scan of the alignment system of a lithography device may deviate far from the preset threshold constant value, which will have a great impact on the alignment signal processing results

Because of the side lobe caused by the attenuation PSM (phase shift mask: a kind of patterning component) with high light transmittance, sometimes the side lobe signal is enough to exceed the threshold constant value, and it is adopted and processed by the signal processing program, which is inevitable It will lead to a large deviation in the signal processing results, and the correlation of the results will be greatly reduced, thereby greatly reducing the reproducibility accuracy of the alignment signal processing

[0006] Theoretically, the scanning center of each alignment scan of the alignment system of a lithography device should be near the alignment position, otherwise, if the distance between these two positions is large, it may cause the peak of the desired optical information to vary with the scanning position. In the case of alignment within the scan range, that is, the capture range requirements are not met, so the sampling data will also have a greater impact on the signal processing results, and will greatly reduce the repeatability of the alignment

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