Research On Multi-mode Measurement Technology Of White Light Interference Based Atomic Force Probe Scanning Profiler

Surface topography is an important geometric feature for high-end manufacturing products and scientific research prototypes.The diversified development of surface topography requires high-end surface topography measuring instruments that are suitable for quality,manufacturing process and functional analysis.The horizontal and vertical resolution and measurement range of surface topography measurement technology have been put forward higher requirements.This paper focuses on the multi-mode measurement technology of white light interference based atomic force probe scanning profiler to meet the requirements of diverse micro-nano surface topography and structure measurement in industrial measurement.The main research content is as follows:Aiming at the problem of white light interference fringe distortion formed on the atomic force probe cantilever,a robust zero-order fringe localization algorithm is proposed.Combining the discrete wavelet transform with soft threshold filtering and gradient compression,the white light interference signal is preprocessed to eliminate distortion and enhance the robustness of the zero-order fringe localization algorithm.Hilbert transform is used for phase analysis of the preprocessed interference signal to achieve high-precision positioning of the zero-order fringe.A wide range of vertical scanning tracking measurement mode based on laser interferometry is studied to meet the requirements of large-scale and high-resolution surface topography and structure measurement.White light interference zero-order fringe positioning is used to realize the vertical scanning and tracking of atomic force probe on the measured surface.Combining the real-time measurement of large-scale tracking displacement by the laser interferometer system to realize a wide range of high-resolution surface topography measurement.A traceability measurement method based on monochromatic light interference for atomic force probe scanning is studied to meet the traceability measurement requirements for ultra-precise surface topography.Phase analysis of monochromatic light interference signal on the atomic force probe cantilever is performed.Then the phase change at the probe tip is directly obtained during measurement,so that the measured surface topography is restored.The measurement results can be directly traced to the wavelength of light source to realize traceability measurement of ultra-precise surface topography.The propsed multi-mode measurement technology is applied to the developed white light interference based atomic force probe scanning profiler.The test and application experiments are carried out to verify that the white light interference based atomic force probe scanning profiler is suitable for diverse micro-nano surface topography and structure measurement in industrial measurement.