An angular momentum-based wafer defect detection method and system

By employing a wafer defect detection method based on angular momentum, which utilizes vortex beams and wafer rotation scanning, the problem of large field of view and high resolution detection is solved, and efficient defect depth and type determination is achieved.

CN122409690APending Publication Date: 2026-07-17QINGSOFT MICROVISION (HANGZHOU) TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
QINGSOFT MICROVISION (HANGZHOU) TECH CO LTD
Filing Date
2026-06-12
Publication Date
2026-07-17

AI Technical Summary

Technical Problem

In existing technologies, wafer defect detection cannot simultaneously meet the imaging requirements of a large field of view and high resolution, and determining the location of defects, especially their depth, requires multiple movements of the objective lens or wafer, resulting in low detection efficiency.

Method used

A wafer defect detection method based on angular momentum is adopted. By converting laser into vortex beams carrying different topological charge values ​​I, a ring pupil is formed by using a spiral phase plate and a central blocking aperture. Combined with the rotational scanning of the wafer, multiple detection beams are obtained for interference signal processing to invert the axial depth and three-dimensional position of the defect.

Benefits of technology

It achieves large field of view and high resolution detection without increasing the physical diameter of the objective lens or complex freeform surface correction, and can simultaneously determine the depth and type of defects, thus improving detection efficiency.

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Abstract

The application relates to a wafer defect detection method and system based on angular momentum. The wafer defect detection method comprises the following steps: acquiring a multilayer detection light beam; calculating an angular position coordinate; dividing a plurality of concentric annular zones on a wafer surface; focusing the multilayer detection light beam on different concentric annular zones according to a topological charge value I and rotating the wafer to enable the multilayer detection light beam to circumferentially scan the corresponding concentric annular zones; collecting the detection light beam reflected by the wafer surface as signal light; performing interference on the signal light and laser to obtain a frequency domain modulation image; performing phase-locked demodulation on the frequency domain modulation image to obtain a phase signal corresponding to each topological charge value I; inversely calculating the axial depth Z of a defect according to the phase signal; and determining the three-dimensional space position of the defect on the wafer according to the axial depth Z. The wafer defect detection system comprises an illumination module, a lens module, a wafer stage and a detection module. The application can meet the imaging requirements of a large field of view and high resolution and can determine the defect position.
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