Wafer detection method and wafer detection apparatus

Abstract

The invention relates to a wafer detection method and a wafer detection apparatus. The method comprises enabling grazing incidence of two or more than two coherent light beams onto the to-be-measured wafer and forming interference fringes on the to-be-measured wafer; performing rotation and translation for the to-be-measured wafer so that the interference fringes scan the to-be-measured wafer; scattering the interference fringes by particles on the surface of the to-be-measured wafer and forming time-related scattered light signals; detecting the scattered light signals, treating the scattered light signals based on characteristic frequency corresponding to the particles at different positions of the to-be-measured wafer, and forming frequency-dependent detection information; and obtaining the distribution information of the particles on the to-be-measured wafer based on the detection information. The wafer detection method is high in precision and throughput; and the wafer detection apparatus is low in design difficulty and cost.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a wafer detection method and a wafer detection device. Background technique [0002] In the semiconductor process, the cleanliness of the wafer surface is one of the important factors affecting the reliability of semiconductor devices. How to remove contamination and foreign matter particles on the wafer surface has always been a research hotspot in the field of semiconductor technology, and how to detect the cleanliness of the wafer surface after cleaning has also become a concern of semiconductor technicians. [0003] The optical inspection method has become one of the most commonly used wafer inspection methods due to its advantages of not destroying the cleanliness of the wafer surface and being able to detect in real time. The optical detection method uses optical scattering intensity measurement technology to detect the presence or absence of particles on the wafer ...

AI Technical Summary

Problems solved by technology

The characteristics of large numerical aperture and high resolution obviously put forward high requirements on the optical part of the detection system, which also increases the production cost

[0011] In addition, since each spot is 3 microns x 9 microns in size on the wafer, that is, the spot size is 3 microns in diameter, at a wavelength of 355 nanometers, the numerical aperture of the incident light needs to be between 0.11-0.12. When the DOE is introduced at the same time, the volume of the incident light system will be relatively large and occupy a large space

Due to the limited space, the incident light system has a certain limitation on the numerical aperture of the lighting system, which prevents the lighting system from being close to the surface of the wafer to be tested

The light intensity scattered by particles is mainly concentrated in the solid angle direction of the grazing angle close to the wafer surface, and the limited numerical aperture of lighting will reduce the signal intensity of particle detection, thereby affecting the detection accuracy

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