高 分 辨 白 光 干 涉 -共 焦 显 微 三 维 形 貌 测 量 传 感 器 研 制

To address the difficulty of a single measurement mode in simultaneously meeting the high-spatial-resolution imaging and inspection requirements of diverse complex micro/nanostructures, a high-resolution three-dimensional topography imaging and measurement method based on the dual-optical-path integration of white-light interferometry and confocal microscopy is proposed. In this method, a beam-splitting prism and a shared tube lens are used to realize coaxial beam combination and spatial multiplexing of the white-light/laser illumination and detection paths, while a galvanometer is introduced to achieve rapid lateral scanning in the confocal mode. The system enables in situ switching between the two measurement modes. White-light interferometry is used for nanometer-scale measurement of large-area surface topography, whereas confocal microscopy is used for precise localization of complex edges. In this way, the high axial resolution of white-light interferometry is combined with the high lateral resolution of confocal microscopy, enabling high-precision three-dimensional topography measurement of different micro/nanostructures. Based on this method, a miniaturized multimode white-light-interferometry/confocal measurement sensor system was developed. Experimental results show that the system can realize dual-mode three-dimensional topography measurement. In the smooth-plane test, the axial repeatability was better than 2 nm, and in the standard step-grating test, the height standard deviation was less than 2% of the nominal height. The integration of white-light interferometry and confocal microscopy in micro/nano measurement provides a reference for efficient and precise three-dimensional topography measurement of micro/nanostructures.