Method for detecting interference shape of broadband spectrum based on longitudinal phase splicing

Abstract

The invention relates to a method for detecting an interference shape of a broadband spectrum based on longitudinal phase splicing. The method comprises the following steps: controlling an interference objective to longitudinally scan and move through a piezoelectric ceramic precise moving station by virtue of a Mirau-type white light interference system, and storing a series of collected broadband spectrum interference images; calculating the collected interference images by virtue of frequency domain and time domain algorithms, so as to obtain the distribution of modulation degrees and wrapped phases; setting a reasonable modulation degree threshold, and determining whether to carry out phase expansion on a pixel point according to the size of each pixel point; and carrying out longitudinal phase splicing by virtue of effective regions of the two adjacent images, and finally splicing the interference images, so as to obtain absolute phase distribution of the whole measured shape and the surface shape restoration. The method has the characteristics that the measurement precision is high, and the influences caused by the scanning moving precision are low; and particularly, aiming at the detection of a high-depth micro-nano structure, the measurement speed is high, and the practicability is strong.

Description

technical field [0001] The invention belongs to the field of optical detection, and in particular relates to a wide-spectrum interference shape detection method based on phase longitudinal splicing. Background technique [0002] Micro-nanostructures refer to functional structures with characteristic sizes ranging from micrometers to nanometers. They are widely used in the fields of metamaterials, microelectronics, aerospace, environmental energy, biotechnology, etc., and have irreplaceable value in the fields of national economy and national defense. It is of great significance to promote the development of technology, economy and society in the information age. The high-precision three-dimensional detection technology of micro-nano structure runs through the whole process of micro-nano device processing, which is the basis and guarantee of high-precision device processing, and also the basis and premise of the development of micro-nano manufacturing technology. With the co...

AI Technical Summary

Problems solved by technology

However, in the above methods, there are problems such as unstable light intensity of the interferogram and insufficient step accuracy due to unstable light intensity and external environmental interference, which lead to three-dimensional shape detection errors.

[0006] Due to the current three-dimensional shape detection methods of micro-nano structures at home and abroad, the measurement stability is insufficient, and they are seriously affected by external interference.

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