Characterization of wafer surface morphology based on atomic force microscopy

This paper develops a probe scanning AFM system for 12-inch wafer surface topography characterization. Firstly, a fast Gaussian filter convolution algorithm for 2D and 3D surface roughness is proposed, and the computation time is reduced by iterative approach. Second, the principle of AFM and the roughness measurement method are investigated. Finally, the same wafer is compared and measured using AFM and white light interferometer. The results show that the measurement error of the AFM is around 0.5% and the repeatability of the measurement is controlled in the order of picometer if the white light interferometer measurement is used as the reference value. In addition, the 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.