Fabrication of ultra-small-diameter optical-fiber probe using acid-etch technique and CO₂ laser for 3D-micro metrology

This paper presents a system for measuring a 3D microstructure using an optical-fiber probe. A stylus shaft was fabricated using an acid-etch technique.We investigated the process of fabricating a stylus tip using an adhesive method, an arc-discharge method, and a CO₂-laser technique. The characteristics of the stylus shaft in the process of detecting the displacement were then described. Finally, in the case wherein the stylus tip was fabricated using an adhesive, the deformation of the stylus tip caused by the contraction of an ultraviolet curing resin, which was used to glue the stylus shaft to the stylus sphere, was analyzed using a finite-element method. Accordingly, a stylus shaft and tip with respective diameters of 0.4 µm or greater and 1 µm or greater were manufactured using the adhesive method. Moreover, the results helped confirm that stylus tips with diameters in the ranges of 20-196 and 1.2-300 µm were fabricated using the arc-discharge method and CO₂-laser technique, respectively, with high yield. In addition, the results of the finite-element method revealed that the maximum elastic-deformation volume was approximately 0.8 nm and the effect of the contraction of the ultraviolet curing resin is minimal.