Method and device for correcting uneven thickness-induced depolarization effect in spectral ellipsometry

Abstract

The invention provides a spectral ellipsometry thickness non-uniform source depolarization effect correction modeling method and device, and the method comprises the steps: carrying out the measurement through a Mueller matrix ellipsometer, obtaining all Mueller matrix elements of a to-be-measured sample at a time, and obtaining the depolarization information of the sample. Then, by reasonable assumption of a distribution function with non-uniform thickness and full consideration of the non-uniformity of the thickness of each layer, reasonable nodes are selected and weight accumulation is performed to obtain a forward modeling average Mueller matrix of the sample; when the thickness distribution of each layer of the sample is random, Gaussian distribution nodes and weights are adopted, multi-dimensional calculation is simplified into one-dimensional calculation, and the calculation efficiency is greatly improved. Finally, fitting and information extraction such as optical constants andthickness values of parameters of the to-be-measured sample are carried out through a nonlinear regression algorithm. According to the invention, correction of a non-uniform thickness depolarizationeffect of spectral ellipsometry can be realized, rapid data analysis of on-line measurement in various optical thin film devices and various nanometer manufacturing processes can be realized, and optical and set parameters of the nanometer material can be extracted.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of ellipsometry, and in particular to a modeling method and device for correcting the depolarization effect of a source of non-uniform thickness in spectral ellipsometry. Background technique [0002] Ellipsometry is a method of measuring nanometer parameters using the polarization characteristics of light. The measurement process is simple and fast, and can effectively characterize the geometric and optical parameters of thin film materials. It has the advantages of fast, accurate and non-destructive. Indispensable technical means for industries such as flat panel display and solar cells. The basic principle is that a beam of known polarization state is incident on the surface of the sample to be tested, and the optical constant and thickness of the film are obtained through the change of the polarization state (amplitude ratio and phase difference) before and after the reflection ...

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Problems solved by technology

[0005] The embodiment of the present invention provides a spectral ellipsometric measurement thickness non-uniformity source depolarization effect correction modeling method and device, which is used to solve the existing ellipsometric analysis method to analyze the special case of wedge-shaped thickness non-uniformity, in complex In the case of uneven thickness and rapid industrial large-area measurement, it is unreasonable to use the above special assumptions

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