Optimization of Spiral Scanning Center Error Based on Differential Confocal

Abstract

A spiral scanning center error optimization method based on differential confocal (ODC) is proposed, allowing for high-precision and high-efficiency non-contact measurement of microstructure surface topography. To begin, a probe centering method based on grating rotation successive approximation is designed to reduce the centering error of 3D shape measurement during spiral scanning. The surface morphology of the standard sample was then measured using an experimental platform based on the ODC principle. The center error is within $0.75\ \mu\mathrm{m}$, and the maximum deviation is within 1.4067%, which is consistent with the commercial white light interferometer. This method has a lot of potential for accurate and efficient 3D surface topography measurement.