Multi-range double probe device for measuring thickness of metal film

Abstract

The invention discloses a multi-range double probe device for measuring the thickness of a metal film. The device includes an excitation source, a double probe, a collection module and a central processing module, wherein the excitation source is used for providing an oscillating source, the double probe has a first coil channel and a second coil channel and correspondingly includes a first coil and a second coil, the penetration depth of the second coil being larger than that of the first coil, the collection module is used for generating magnetic field right below the probe and collecting the equivalent impedance of the probe when generating induced magnetic field on the surface of a to-be-measured metal film right below the probe, and the central processing module is used for switchingthe coil channels to make the first coil or the second coil work, obtaining the changing values of coil impedance according to the equivalent impedance, and obtaining the thickness of the to-be-measured metal film according to the changing values of the coil impedance. The device can measure the thickness of the metal films through a non-contact manner, and therefore, fixed point coordinate measurement can be performed, film edge measurement can be performed, and the resolution and stability of the probe can be effectively enhanced.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing, in particular to a multi-range dual-probe device for metal film thickness measurement. Background technique [0002] In the related art, the probe method is used to measure the metal thin film, and four probes are used to measure the resistance in a rectangular area, and then the thickness is calculated according to the resistance value and the resistivity of the measured metal thin film, so as to complete the measurement of the metal thin film; The non-contact measurement uses the eddy current principle to calibrate the metal film, so as to deduce the relationship between the eddy current signal and the film thickness, so as to achieve the purpose of measuring the film thickness. [0003] However, the probe contact measurement will cause slight damage to the metal film to be tested, and cannot measure the thickness of the metal film to be tested in real time, such as in the CMP (...

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Problems solved by technology

[0003] However, the probe contact measurement will cause slight damage to the measured metal film, and cannot measure the thickness of the measured metal film in real time, such as in the CMP (Chemical Mechanical polishing, chemical mechanical polishing) process

The area corresponding to the eddy current measurement is too large, and it is impossible to measure at a fixed point, and it is impossible to measure the edge of the metal film, such as the edge of the wafer. Maintain high resolution in a large range

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