Three-dimensional shape measurement method of coated devices based on white light scanning interference

Abstract

The invention relates to a coated device three-dimensional topography measurement method based on white-light scanning interference. According to the method, a corresponding substrate part interference signal zero-optical-path-difference position extraction process is converted to a problem of calculating relative displacement of an interference signal between different pixels through a generalized related time delay estimation method, thereby accurately calculating substrate part three-dimensional topography information. Furthermore, the surface film thickness of a to-be-measured coated device can be obtained by means of the measurement method. The coated device three-dimensional topography measurement method has advantages of high calculation precision and high noise resistance. Central wavelength calibration of a light source is not required. Furthermore no requirement for envelope shape of a white-light interference signal is realized. High convenience is application is obtained.

Description

technical field [0001] The invention relates to the field of measurement, in particular to a method for measuring the three-dimensional shape of a coating device based on white light scanning interference. Background technique [0002] At present, the development of process technology has promoted the development of thin film technology, and the theory, process and measurement of thin film technology have formed a complete system. With the rapid development of micro-electro-mechanical system (Micro-Electro-Mechanical System, MEMS) devices and semiconductor devices, surface coating technology has been more applied. [0003] Due to the increasing importance of optical thin films, various technologies for detecting thin films have also developed rapidly. The measurement of thin films includes optical, mechanical, and electrical performance measurements. The measurement of optical properties includes macroscopic measurement of thin film, thin film thickness measurement and refr...

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Problems solved by technology

Compared with the photometric method, the ellipsometry has the advantage of high sensitivity, but the test results are greatly affected by the outside world, and a complex mathematical model is required to solve the thickness

Moreover, the ellipsometry has limitations in measuring film thickness, because it has periodic problems, and is not suitable for the measurement of too thick film layers. When the actual film thickness exceeds 1 μm, it is already difficult to measure accurately.

[0007] It can be seen that both photometry and ellipsometry have certain limitations. These two methods can only perform single-point measurement. If you want to obtain film thickness information within a certain range, you must perform horizontal two-dimensional scanning. The spot has a certain size, which limits the lateral resolution of the measurement

[0008] In summary, the above two methods can only measure the thickness of the film, but cannot measure the morphology of the substrate.

In practical applications, it is necessary to obtain film thickness information within a certain range and measure the three-dimensional shape of the substrate, which cannot be solved by traditional measurement methods.

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