Research on nanoscale grid pitch characterization method based on metrological atomic force microscopy

This paper develops a metrological atomic force microscopy system for nanoscale grid pitch characterization. Firstly, the principle of metrological atomic force microscopy and the roughness measurement method are introduced. Second, analyzed the evaluation principle of micro nano feature structures, mainly analyzed the evaluation algorithm of grid pitch, and developed an evaluation program using MATLAB. Then multiple methods are applied to measure grid pitch, and an evaluation program was developed using MATLAB to evaluate and calculate the measurement data, verifying the feasibility and reliability of each evaluation algorithm. Finally, the same grid pitch is compared and measured using metrological AFM and white light interferometer. The results show that the average measurement value is 200.14 nm, the standard deviation is 0.20 nm, and the difference is within the allowable error range. In addition, the metrological atomic force microscopy measurement method has the characteristics of high measurement accuracy, small measurement range, slow speed and no requirement for material, which provides technical support for process personnel how to choose the measurement scheme.