High Frequency Topography Compensation Method of White Light Scanning Interferometry Based on Transfer Function

A white light scanning and transfer function technology, which is applied in the field of white light scanning interferometry, can solve the problems of limited measurement accuracy and accuracy comparison, different surface space band restrictions, and difficulty in affecting the transfer function of the interferometer. Simple and effective compensation method

Active Publication Date: 2021-11-05
DALIAN UNIV OF TECH
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AI Technical Summary

Problems solved by technology

It is difficult to calculate the influence of each part on the transfer function of the interferometer in the actual measurement compensation
Affected by the interferometer itself and various other factors, the transfer function response at some spatial frequencies is different from the calibrated transfer function, so there will be problems in correcting the power spectral density measurement value only by relying on the transfer function curve given by the merchant
[0005] In summary, the existing white light scanning interferometer and other measuring instruments have different technical principles and different surface space band restrictions, and the roughness measurement results cannot be directly compared, which limits the comparison of measurement accuracy and accuracy

Method used

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  • High Frequency Topography Compensation Method of White Light Scanning Interferometry Based on Transfer Function
  • High Frequency Topography Compensation Method of White Light Scanning Interferometry Based on Transfer Function
  • High Frequency Topography Compensation Method of White Light Scanning Interferometry Based on Transfer Function

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Effect test

Embodiment 1

[0058] Such as figure 1 As shown, the high-frequency shape compensation method of the white light scanning interferometry method based on the transfer function of the present invention, the specific compensation steps are: the initial shape measured by the white light interferometer, and the Fourier transform of the shape is solved to obtain the phase frequency curve and amplitude-frequency curve, solve the PSD of the power spectral density curve for the amplitude-frequency curve, use the transfer function to obtain the corrected PSD, and combine the corrected PSD and the phase-frequency curve to obtain the compensation shape by using the inverse periodogram method.

[0059] The present invention adopts software to carry out measurement process simulation simulation and compensation, and concrete method is as follows:

[0060] S1: Given the triangular wave signal to simulate the shape, use mathematical software combined with the white light interferometry process to simulate t...

Embodiment 2

[0064] The New view 9000 white light scanning interferometer of ZYGO Company was used to measure the morphology of No. 3000 ultra-precision ground silicon wafers, such as Image 6 As shown in (a), use mathematical software to randomly extract k groups (k=20) of two-dimensional profile curves with a length of 20 μm from the vertical wear scar direction, and use mathematical software to extract the power spectral density curve PSD of the above-mentioned shape Ci , wherein i=1, 2, 3, ..., k, adopt the XE-200 atomic force microscope of Park Systems Company to measure the morphology of the same No. 3000 ground silicon wafer sample, as Image 6 As shown in (b), use mathematical software to randomly extract k groups (k=20) of two-dimensional profile curves with a length of 20 μm from the vertical wear scar direction, and use mathematical software to extract the power spectral density curve PSD of the above-mentioned shape Ai , to calculate the average power spectral density curves me...

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Abstract

The invention discloses a transfer function-based white light scanning interferometry high-frequency profile compensation method, comprising the following steps: calculating the Fourier spectrum of the profile measurement result of the white light scanning interferometer; calculating the power spectral density by using the amplitude-frequency curve Curve; the power spectral density curve and the square of the transfer function are corrected to obtain the corrected power spectral density curve; the reverse periodogram method is used to restore the shape. The invention utilizes the transfer function of the white light interferometer to directly compensate the spectral information of the shape directly measured by the white light interferometer, and simulates the measured shape of the white light interferometer with part of the high-frequency information. The invention uses the transfer function to directly compensate the measured topography without changing the software and hardware of the measuring instrument, and the compensation method is simple and effective; at the same time, the precision and accuracy of white light scanning interferometry for ultra-precise surface topography are improved, especially for topography. The surface profile and surface roughness lay the foundation for the measurement of ultra-precision machining.

Description

technical field [0001] The invention relates to the field of white light scanning interferometry, in particular to a transfer function-based white light scanning interferometry high-frequency profile compensation method, which is used to realize compensation of white light scanning interferometry profile results and improve measurement accuracy. Background technique [0002] The white light scanning interferometer is based on the principle of white light interference, and determines the surface topography by scanning and positioning the interference fringes. Its measurement accuracy is as high as nanometer or even sub-nanometer, and it will not damage the surface of the workpiece. It is widely used in ultra-precision machining surface topography measuring. However, due to the different measurement principles of each measuring instrument, it is difficult to obtain an accurate and uniform topography when different instruments measure the same surface. Intercomparisons of inst...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01B9/02G01B11/24G01B11/30
CPCG01B9/02043G01B9/02048G01B9/02055G01B9/02084G01B9/0209G01B11/2441G01B11/30
Inventor 闫英李萍周平安奕同马锦伟
Owner DALIAN UNIV OF TECH
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