Development of a High-Precision Multifunctional Probe for Measuring Microstructures

An increasing number of micro/nano-components with complex structures have emerged in recent years. Different kinds of feature sizes usually exist in a single component and require the use of instruments with nanometer-level accuracy. The traditional types of equipment cannot meet the current demands because of their lack of function and effectiveness. In this study, a multifunctional probe is designed by combining the interference and focusing principles. The Linnik principle is adopted in the interferometry module for its high vertical resolution and large horizontal range and its ability to measure surface topography. The focusing module modified from a Blue-ray DVD pickup head has a high horizontal resolution and a large vertical range suitable for measuring step height and line/groove width. The two modules share a polarizing beam splitter and an objective lens to reduce probe size. Then, the probe is manufactured, calibrated, and verified by measuring the surface topography with a reference height of 100 nm, a step height of approximately $4~\mu \text{m}$ , and a diameter of approximately $25~\mu \text{m}$ . The proposed probe has a high resolution and large range in 3D and can measure high-precision components with multiple features.