并行差动共焦跨多尺度纳米精度表面形貌检测关键技术研究

Currently there exists several un-resolved conflicts about measurement precision, measurement range and measurement efficiency regarding the research of microscopic surface profiling methods. Therefore, this project proposes a fast microscopic-surface topography inspection method, which features a multi-scale inspection range with a nanometer-scale sensitivity. The main research contents include: ① Study the mechanisms of parallel object-side differential confocal longitudinal surface height measurement method, spatial-light modulated super-resolution imaging method, and even-illumination method, to establish a novel microscopic surface profiling method with nanometer-scale sensitivity in three (XYZ ) dimensions for the whole field of view. ② Create an error compensation model and apply it to realize accurate measurement. ③ Set up a proof-of-concept microscopy that is capable of surface profiling with nanometer-scale sensitivity in three (XYZ ) dimensions for the whole field of view within 2 seconds in a non-scanning manner. ④ Propose and study the mechanism of tilt-camera-based autofocusing method, and set up an experimental platform to test its accuracy and usefulness in the microscopic surface profiling process using even-velocity sub-aperture scanning approach over a measurement range of multiple inches. Novelty of the proposal includes: ① establishing the parallel object-side axial measurement theory and tilt-camera-based autofocusing method; ② creating a fast and accurate surface topography measurement method that could complete surface profiling of an area with a couple of inches in diameter within an hour at a range of nanometer sensitivity in XYZ directions.. As a result, the method proposed in this project overcomes the shortcomings of the existing surfacing profiling methods, such as having a relatively low efficiency, with a complex structure, and not having simultaneous nanometer sensitivity in all XYZ directions. Successfully implementing this project will lay a solid foundation for a multi-scale range, nanometer-scale sensitivity non-contact non-scanning 3D surface profiling instrument.

针对微观表面形貌检测精度、范围及效率三者难以同时兼顾的问题，拟建立跨多尺度纳米精度微观表面形貌快速检测方法。主要研究内容：①基于并行差动纵向测量、结构光照明超分辨率成像及均匀光照明机理，建立全视场范围2秒内完成XYZ三向均具纳米量级精度的微观形貌检测方法；②建立误差补偿模型，实现测量误差自动补偿与准确测量；③构建英寸量级测量范围、纳米量级精度、秒量级速度的表面形貌测量实验样机,验证理论方法的准确性与实用性；④提出倾斜摄像头自动聚焦理论，验证其在英寸量级宏观范围，以匀速子孔径重叠扫描方式进行表面微观检测应用中的准确性及实用性。创新点：①建立并行差动纵向测量和倾斜摄像头自动聚焦理论；②建立快速完成英寸直径范围具有XYZ三向均达纳米量级精度表面形貌测量方法。从而克服现有形貌检测方法效率低、结构复杂、难达到XYZ三向纳米量级测量精度的问题，为跨多尺度纳米精度三维形貌检测仪器设计和制造提供科学依据。

针对微观表面形貌检测精度、范围及效率三者难以同时兼顾的问题，本项目研究跨多尺度纳米精度微观表面形貌快速检测方法。（1）建立了并行物方差动共焦3D显微测量方法，实现纵向测量精度1nm@100×NA=0.9，相对标准差≤0.2%，在图像尺寸为2018×512时的效率为13fps的3D显微测量；（2）建立了多焦点结构光显微超分辨率成像方法，突破衍射极限提升横向分辨率；（3）完成CV值为1%的消杂均匀光照明系统的搭建；（4）提出基于倾斜摄像头的实时自动聚焦方法，提升了纵向工作范围；（5）建立误差补偿模型，对于光照不均、非均匀照明及光学成像系统场曲造成的测量误差等问题进行快速自动补偿；（6）本项目研制的并行物方差动共聚焦显微镜实验样机，可实现XY方向亚微米精度、Z方向纳米精度的快速跨多尺度微观形貌高精度测量。能够满足精密和超精密加工、微制造、光学等领域微观表面形貌测量的需要。.关键数据：横向分辨/轴向定位精度/轴向测量范围/16×16毫米面积测量时间分别为：4×物镜：2.19μm/0.6μm/90μm/12.9秒；10×物镜：0.69μm/0.1μm/20μm/86.8秒；20×物镜：0.388μm/0.05μm/5μm/192.5秒；100×物镜：0.17μm/0.001μm/NA/NA。.科学意义：建立了轴向纳米精度视频帧率3D显微测量方法，为超精密3D显微测量进入高通量或生产线在线测量奠定基础。