Fig. 1. Process diagram for preparing standard line width samples

Fig. 2. Nanometer value traceability system

Fig. 3. Selection of grating pitch

Fig. 4. (a) Schematic diagram of line edge; (b) Schematic diagram of local line width

Fig. 5. (a) \begin{document}$ {\sigma }_ {\rm{LER}} $\end{document}=0, while \begin{document}$ {\sigma }_ {\rm{LWR}} $\end{document} is large; (b) \begin{document}$ {\sigma }_ {\rm{LWR}} $\end{document} is very small, and \begin{document}$ {\sigma }_ {\rm{LER}} $\end{document} is large

Fig. 6. The SEM magnification is \begin{document}$ 80\;\mathrm{K}\times $\end{document}, the schematic diagram of grating grid selection

Fig. 7. SEM calibration factor junction error bars under different magnifications

Fig. 8. (a) Simulation pattern of linewidth standard; (b) Central line width extraction map; (c) Schematic diagram of central linewidth extraction

Fig. 9. (a)-(c) are the measurement results of 100 nm, 200 nm, and 500 nm linewidth at different magnifications, respectively; (d) Average line width

Fig. 10. (a)-(c) are 100 nm, 200 nm, 500 nm left and right line edge roughness and line width roughness respectively