Wafer detecting method and wafer detecting device

Abstract

The invention provides a wafer detecting method and a wafer detecting device. The wafer detecting method provided by the invention comprises the following steps: measuring light is produced; a detecting light spot is formed by the measuring light on a wafer to be detected; the wafer to be detected is scanned by the detecting light spot; the measuring light is scattered by particles positioned within the range of the detecting light spot, so as to form scattered light; the scattered light is detected, and a corresponding time-related scattered light signal is formed; and distribution information of the particles on the wafer to be detected is obtained on the basis of the time-related scattered light signal. The wafer detecting device comprises a light source for providing the measuring light, a moving and rotating platform for bearing the wafer to be detected and enabling the wafer to move or rotate, a photoelectric detector for detecting the scattered light at a certain frequency, and a data processing unit for obtaining the distribution information of the particles on the wafer to be detected according to the time-related scattered light signal detected by the photoelectric detector. The wafer detecting method provided by the invention has the advantage of relatively high efficiency, and the wafer detecting device provided by the invention has the advantage of relatively low design difficulty.

Description

technical field [0001] The present invention relates to the technical field of semiconductors, and in particular, to a wafer inspection method and a wafer inspection 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 the 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 capable of real-time inspection. The optical detection method uses the optical scattering intensity measurement technology to detect the presence or absence...

AI Technical Summary

Problems solved by technology

[0007] First, the beam splitting component in the patent is a diffractive optical element (DOE). Since the light transmission efficiency of the DOE is between 60% and 70%, the detection light will lose about 1 / 3 of the light intensity when passing through the DOE. , while DOE increases the difficulty for the design of the wafer inspection device;

[0008] Secondly, in order to make the scattered light enter the corresponding photodetector channel instead of entering the photodetector channel corresponding to the adjacent scattered light, the lighting assembly needs a high-resolution imaging system, which requires the lighting assembly to be a large-aperture optical devices, which increases the difficulty of designing lighting components;

[0009] In addition, since the DOE has a larger volume and occupies a larger space, the space of the lighting assembly is reduced, so the numerical aperture (Numerical Aperture, NA) of the lighting assembly is limited, and the lighting assembly cannot be very close to the wafer. On the surface, since the light intensity of the scattered light generated by the particles is mainly concentrated in the solid angle direction close to the wafer surface, the light intensity of the scattered light collected by the lighting assembly with a limited numerical aperture will decrease, correspondingly, this makes the photodetector The detected signal strength is reduced, which affects the detection accuracy

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