Wafer inspection method and wafer inspection device

Abstract

A wafer inspection method and a wafer inspection apparatus. The method comprises: allowing a grazing incidence of the two paths or more than two paths of coherent beams into a wafer-to-be-tested, forming on the wafer-to-be-tested a light spot having interference fringes; rotating and translating the wafer-to-be-tested, allowing the light spot having the interference fringes to scan the wafer-to-be-tested; particles on a surface of the wafer-to-be-tested scattering the interference fringes, forming a time-related scattered light signal; detecting and processing the scattered light signal, forming frequency-related inspection information, and allowing for acquisition from the inspection information, on the basis of a system-configured parameter and corresponding locations of the particles on the wafer-to-be-tested, of a characteristic frequency signal corresponding to the particle scattering, and for acquisition of distribution and size information of the particles on the wafer-to-be-tested on the basis of the inspection information. The wafer inspection method of the present invention has increased precision and increased throughput, while the wafer inspection apparatus is of reduced difficulty in design and of reduced costs.

Description

Technical field [0001] The present invention relates to the field of semiconductor technology, 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 contamination and foreign particles on the surface of the wafer has always been a research hotspot in the field of semiconductor technology, and how to detect the cleanliness of the surface of the wafer after cleaning has also become a concern for semiconductor body 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 real-time inspection. The optical detection method uses optical scattering intensity measurement technology to detect the presence of particles on the wafer surface,...

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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