Reference gage calibration methods of probe nanometry systems

Abstract

Reference gage calibration methods of probe nanometry systems are considered in this work. Existing methods for calibrating reference standards provide high measurement accuracy, but at the same time are distinguished by a high complexity of practical implementation, in particular, the interferometric method, or low accuracy, but with simple practical implementation. Therefore, the urgent task is to develop a calibration methodology that provides a sufficiently high measurement accuracy with a relatively simple practical implementation. The paper proposes a methodology based on the combined use of two methods: a comparative assessment of the step heights of the calibrated gages using one of the probe nanometry systems and the precision measurement of the step height of one of the calibrated gages by computer three-dimensional reconstruction of images in a scanning electron microscope. The components of the measurement uncertainty arising when determining the height of the steps of the calibration standards are investigated. The calculated value of the expanded uncertainty showed that the achievable measurement accuracy is comparable to the accuracy of the interferometric method with a simpler practical implementation. Practical testing of the proposed methodology has shown that the use of calibration techniques developed on its basis provides high accuracy and reproducibility of the results obtained.