Microtopography rapid measurement method suitable for white light scanning interference

Abstract

The invention discloses a microstructure rapid measurement method suitable for white light scanning interference, and the algorithm comprises the steps: controlling piezoelectric ceramics to carry out time sequence vertical scanning within a certain scanning length according to a micro step pitch through a software program of an upper computer, and collecting and storing one interferogram in a computer when each step is moved; carrying out adaptive median filtering processing on the stored time sequence interferogram; finding out the position of the maximum light intensity value of each pixel point in the time sequence interferogram by adopting a hypersymmetric search method, recording the frame number of the interferogram where the position is located, and preliminarily calculating the height information of the morphology according to a related formula; and extracting phase information of the interference fringes by using a seven-step phase shift algorithm, and unwrapping according to a related formula in combination with a preliminary calculation result to accurately recover the microstructure of the tested sample. The method solves the problems that noise singular point interference and adjacent pixel point phase change cannot exceed 2pi in a phase shift algorithm, effectively reduces the influence caused by scanning errors, and has the characteristics of high measurement precision, simple algorithm, high applicability and the like.

Description

Technical field [0001] The present invention relates to the field of precision optical measurement engineering, and more particularly to a micro-morphological rapid measurement method suitable for white light scanning interference. Background technique [0002] With the gradual improvement of processing technology, the use of precision components is increasingly wide, and there is an irreplaceable role in aerospace, in-vehicle systems, imaging lighting and other fields. The quality of the elements can be quantified by measuring the topography of the component. Whether the function in the system is affected, it is important for the quality monitoring of components. Microelectronics, microstructure, MEMS device development on the surface quality of objects and surface morphology, so the accuracy requirements of micro-nano structural detection are also increasing, in which various three-dimensional shape recovery algorithms The study is particularly important. [0003] During the su...

AI Technical Summary

Problems solved by technology

The envelope curve fitting method in this patent is an approximate calculation. When the measured point interference signal changes and the envelope peak value shifts and is not symmetrical with the zero-order fringe position, the error of the algorithm is relatively large, and a large number of calculations are required. Data calculation, it is impossible to obtain the three-dimensional shape of the measured surface at the end of the measurement system scanning

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