An Optical Coordinate Measuring Machine for Nanoscale Dimensional Metrology

Coordinate Measuring Machines (CMMs) are commonly used for geometry verification and replication on solid parts and work pieces on many scales. As the parts predicable continues to grow smaller and smaller, so grows the need to accurately measure the dimensional accuracy of these parts. This is partly because of how the critical part tolerances become as dimensions shrink and geometries become more complex. Research is currently underway at the Georgia Institute of Technology to develop a system for dimensional metrology at the nano-scale. The goal is to develop a versatile, non-contact, three-dimensional system capable of making accurate measurements on the nano level of form attributes of micro electro-mechanically manufactured parts. The Nano-CMM developed consists of a laser probe, a 6-axis positioning table, and a support frame. This paper describes the calibration of probe, processing of measurement signals, detection of solid edges, and software interface for system automation.