Three-dimensional topography measurement of microsurface based on FBG probe scanning

In order to achieve the measurement of three-dimensional (3D) surface topography of microdevices, this study uses high-sensitivity fiber Bragg grating (FBG) as the sensitive element of the contact measurement probe system and studies the device surface microtopography scanning measurement system based on FBG probe, which is used for the measurement and characterization of micrometer-sized microdevices, with high measurement resolution and low cost. In this study, a low-priced micro-displacement output strategy combining macro- and micro-motion was adopted, and an improved image horizontal distortion correction algorithm was proposed to correct the horizontal distortion of the image. Through the performance experiments of the measurement system, a micro-displacement measurement sensitivity of 12.21 mV/nm and a measurement resolution of 0.46 nm are obtained. The measurement results of bar structure step standard specimens show that the system can distinguish the step height of 200 nm by contact scanning measurement, solve the problem of horizontal distortion in the global distribution of the image, and realize the 3D measurement and characterization of micron-scale surface topography.