Pitch calibration of one-dimensional grating standard by tapping mode nanometrological atomic force microscope

A tapping mode nanometrological Atomic Force Microscope system with an ultra-high resolution three-axis laser interferometer was introduced. In the nano-metrological AFM, laser interferometers are used to measure and control the relative movement between probe tip and sample, and the AFM can reach very high accuracy. By the tapping Mode AFM, the pith of a grating standard was calibrated. The sources of uncertainty were analyzed and the corresponding uncertainty components were given. According to the analysis and calculation, the most reliable value of the grating pitch with nominal value of 240 nm and its combined standard uncertainty are 240.024 +/- 0.157 nm.