An interferometric topography measurement method that takes into account both dynamic range and accuracy

Abstract

The present invention relates to an interference profile measurement method that takes into account both dynamic range and accuracy, including: dividing laser into measuring light and reference light, the measuring light irradiates the surface of the sample to be measured, and forms the light to be measured after being modulated by the surface of the sample to be measured; interfering the light to be measured with the reference light to form an interference pattern; changing the angle of the measuring light so that the measuring light irradiates the sample to be measured at different incident angles, and moving the spectrum information of the surface to be measured that is originally in the high-frequency region and cannot be detected to the low-frequency region in turn and recording it in the corresponding interference image; using a spectrum splicing algorithm to fuse the low-frequency information with different spectrum offsets in the light to be measured recorded in each interference image, and restoring the high-resolution spectrum of the surface to be measured; using a profile correction technology to optimize the three-dimensional profile parsed from the high-resolution spectrum, correcting the system deviation in the measurement and splicing process, and then obtaining a high-precision profile measurement result of the surface to be measured. Compared with the prior art, the present invention has the advantages of large dynamic range, high measurement accuracy, and strong versatility.

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