Wang Bo, Li Jiafu, Luo Mingzhe, Liang Fengshuang, Hu Jiacheng
Key Laboratory of In-Situ Metrology, Ministry of Education, China Jiliang University, Hangzhou 310018, China.
Precision Measurement Laboratory, National Institute of Metrology, Beijing 100029, China.
Sensors (Basel). 2025 Feb 22;25(5):1337. doi: 10.3390/s25051337.
Spectral confocal displacement sensors are non-contact optoelectronic sensors widely utilized for their high accuracy, speed, and ability to measure diverse surfaces. However, challenges including vibration, angular deflection, and surface quality variations can reduce sensor stability and accuracy when performing measurements such as lithium battery wafer thickness, wafer warpage, and optical component surface topography. This study proposes a line-spot-based measurement method using a binary diffractive lens and cylindrical lens with a 20× objective, and then the overall structure is simulated and optimized by using ZEMAX, which realizes a confocal measurement system with a measurement range of 800 μm, line spot length of 3.8 mm, and width of 0.2 mm. The system, calibrated with a nanometer displacement stage, achieved 30 nm resolution and significantly improved dynamic stability (standard deviation (SD) of 0.013 μm) compared to a point spectral confocal sensor (SD of 0.064 μm). The results indicate the proposed sensor exhibits improved stability during scanning measurements.
光谱共焦位移传感器是一种非接触式光电传感器，因其高精度、高速度以及能够测量各种表面而被广泛应用。然而，在进行诸如锂电池晶圆厚度、晶圆翘曲和光学元件表面形貌等测量时，包括振动、角偏转和表面质量变化在内的挑战会降低传感器的稳定性和准确性。本研究提出了一种基于线光斑的测量方法，该方法使用二元衍射透镜和柱面透镜以及一个20倍物镜，然后利用ZEMAX对整体结构进行模拟和优化，实现了一个测量范围为800μm、线光斑长度为3.8mm、宽度为0.2mm的共焦测量系统。该系统通过纳米位移台进行校准，实现了30nm的分辨率，与点光谱共焦传感器（标准差为0.064μm）相比，显著提高了动态稳定性（标准差为0.013μm）。结果表明，所提出的传感器在扫描测量过程中表现出更高的稳定性。
