A new type of nanoscale reference grating manufactured by combined laser-focused atomic deposition and x-ray interference lithography and its use for calibrating a scanning electron microscope

Highlights: • A new type of 1D grating sample fabricated by combining laser-focused atomic deposition and x-ray interference lithography is proposed as a lateral standard for nanometrology. Owing to the applied nanomanufacturing techniques, the grating has (much) better large-range as well as short-range pattern uniformity than conventional samples e.g. fabricated by the e-beam lithography. The grating sample is thus well suited for calibrating the magnification and field distortion of almost all kinds of microscopes, particular SEM. • Calibration of the developed grating sample has been performed by an ultra-precision metrological large-range atomic force microscope. The result indicates that the grating sample exhibits outstanding pattern uniformity: (1) the nonlinear deviation of the grating structures is below +/- 0.5 nm over a measurement range of 5 µm; (2) the maximal variation of the calibrated mean pitch values is lower than 0.01 nm at different locations randomly selected all over the pattern area. • Application of the new sample for accurately calibrating the magnification and nonlinearity of a commercial SEM is demonstrated, showing its advantages of easy-of-use and high accuracy. • Influence of the defocus level of SEM on the calibration result is also demonstrated. • This research offers a feasible solution for highly accurate SEM calibration needed for 3D nanometrology and hybrid metrology demanded in metrology of modern nanoelectronics devices and systems. Calibration of magnification and nonlinearity of scanning electron microscopy (SEM) is an essential task. In this paper, we proposed a new type of 1D grating sample fabricated by combining laser-focused atomic deposition and x-ray interference lithography as a lateral standard for calibrating SEMs. The calibrations of the grating pattern by a metrological large-range atomic force microscope indicate that the grating sample exhibits outstanding pattern uniformity that surpasses conventional samples fabricated by e-beam lithography: (1) the nonlinear deviation of the grating structures is below +/- 0.5 nm over a measurement range of 5 µm; (2) the maximal variation of the calibrated mean pitch values is lower than 0.01 nm at different locations randomly selected all over the pattern area. The proposed new sample is applied for accurately calibrating the magnification and nonlinearity of a commercial SEM, showing its advantages of easy-of-use and high accuracy. The influence of the defocus level of SEM on the calibration result is also demonstrated. This research offers a feasible solution for highly accurate SEM calibration needed for 3D nanometrology and hybrid metrology demanded in metrology of modern nanoelectronics devices and systems.