Method and device for improving accuracy of ultra-thin film layer measured by ellipsometer

Abstract

The invention provides a device for improving precision of measuring an ultra-thin film layer by an ellipsometer. The device comprises a right-angle prism, a plano-convex spherical lens, the ultra-thin film layer and a glass substrate. According to the method and the device, an Otto structure is introduced into the ellipsometer for exciting surface plasma resonance, a curve of elliptical polarization parameters changing along with incident wavelength, incident angle and air gap thickness is tested and analyzed by utilizing micrometer-scale light beams, a thickness of an optical constant of the ultra-thin film layer are obtained through fitting the elliptical polarization parameter curve; and the surface plasma resonance is very sensitive to the optical constant of the film layer, Psi and Delta can be obtained simultaneously by adopting the ellipsometry, and the elliptical polarization test precision can be improved by combining the Psi with the Delta.

Description

technical field [0001] The invention relates to ellipsometer measurement, in particular to a device and method for improving the precision of ellipsometer measurement of ultra-thin film layers. Background technique [0002] The thickness and optical constants of optical films will directly affect the mechanical, optical, electromagnetic and other properties of the film. Accurate determination of the thickness and optical constants of ultra-thin films is particularly important for the study of their optical and electromagnetic properties. Therefore, the precise characterization and control of the thickness and optical constants of thin films play a key role in the preparation, analysis and application of thin films. [0003] Due to the small thickness of the ultra-thin film, there is a certain difference in the optical constants of the ultra-thin film compared with the bulk material, and the current understanding of the ultra-thin film is not deep enough, it is difficult to ...

AI Technical Summary

Problems solved by technology

[0006] Ellipsometry is a general and powerful optical characterization method for non-destructive measurement of the dielectric constant and surface properties of thin films, but it is difficult to achieve high precision requirements by pure ellipsometry, especially for the characterization of ultra-thin films. The result error is large

[0007] Another thin film measurement method is the surface plasmon resonance method, which obtains the optical parameters of the thin film by measuring the light intensity information of the reflected light on the thin film surface. This method is extremely sensitive to ultra-thin thin film measurement by using the resonance effect, but this method Only the intensity information of light can be obtained, and the absolute value of light intensity needs to be measured

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