M.S. Thesis Presentation by Joseph T. Ceremuga II
Friday, November 14, 2003

(Dr. Thomas Kurfess, advisor)

"Optimizing Inspection of High Aspect Ratio Microstructures Using a Programmable Optical Microscope"

Abstract

The inspection of micro parts is critical in today’s engineering world due to the growing popularity of MEMS devices. Optical microscopes are often used so that robust, non-contact inspection may be performed on a micropart scale. The LIGA process is used for fabricating high aspect ratio microparts using X-ray lithography. The process consists of several steps before the final product is realized. Process defects often arise that pose difficulties in measuring these LIGA fabricated parts. These obstacles skew the ability of the optical microscope to locate the desired edge needed for inspection.

This research explores the steps of properly inspecting LIGA fabricated parts using a programmable optical microscope. Topics that will be addressed include properly locating part edges, understanding how changes in microscope settings effect the edge detection for LIGA micropart material, inspection process repeatability, and post-processing methods/software used to suitably qualify these parts. Furthermore, suggestions will be given regarding how to adjust the inspection process to facilitate optimum edge detection and specimen qualification. Software development involved will enable data processing in either individual instances or large batches. Since the LIGA process consists of multiple steps, the capabilities of this research will be applied throughout each step, and resulting data will be overlaid for both visual and numerical appraisal. Thus, this research will enable the evaluation of variations across features, parts, wafers, and all LIGA process steps so that appropriate improvements to LIGA technology may be carried out.