Method for calibrating distance between scan lines of scanning electron microscope by utilizing moires

Abstract

The invention relates to a method for calibrating distance between scan lines of a scanning electron microscope by utilizing moires, which belongs to the technical field of photomechanics. The method comprises the following steps: by using the scan lines of the scanning electron microscope as a reference grating and using the standard grating of a given grating pitch as a specimen grating, enabling the two gratings to generate interference so as to form clear parallel moires, measuring the pixel distance of the moires, and substituting the pixel distance in a deduced inversion formula to calculate the actual physical dimension corresponding to each pixel, thereby obtaining the distance between the scan lines. The method integrates the advantages of high measuring sensitivity, large viewing field and the like in the moire method, can realize real-time in-situ calibration, has the characteristics of high accuracy and simple operation, considers the influences of a plurality of factors, such as the number of scan lines, working distance and the like, and provides favorable foundation for the scanning electron microscope and the scanning electron microscope moire method to be used in measuring micro / nano deformation.

Description

Technical field [0001] A method for calibrating the scanning line spacing of a scanning electron microscope by using moiré belongs to the technical field of photometric mechanics. Background technique [0002] Scanning electron microscopy, as a means of observation and analysis of small-scale samples, is widely used in chemistry, biology, medicine, and metallurgy due to its simple sample preparation, wide range of adjustable magnification, high image resolution, and large depth of field. , Materials, semiconductor manufacturing and microcircuit inspection and other fields. At present, most scanning electron microscopes are only simply calibrated by the manufacturer’s engineers according to the grid or other samples provided by the manufacturer when the instrument is shipped or accepted. Therefore, the calibration accuracy is low. When measuring the length of the object, it is generally and accurate. There are different degrees of deviation between them, which cannot meet the req...

AI Technical Summary

Problems solved by technology

At present, most scanning electron microscopes are only calibrated by the manufacturer's engineers according to the grid or other samples provided by the manufacturer when the instrument leaves the factory or when the instrument is accepted. Therefore, the calibration accuracy is low. When measuring the length of an object, the general and accurate value There are different degrees of deviation between them, which cannot meet the requirements of high-precision measurement such as micro-nano scale measurement

In addition, the measurement accuracy will also change with the change of working distance and other factors, while the traditional calibration method does not consider the influence of working distance

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