NextGen Calibration Utility for Tool Setup and Matching in Real-Time Automated Visual Inspection Systems

Abstract

Metrology and inspection algorithms, no matter how robust, will only exhibit acceptable performance over a finite range of image variation. As our algorithms become more and more advanced, geared towards finding smaller and smaller defects with ever-increasing accuracy, tool matching/calibration has become essential for successful inspection across a large fleet of tools. We present a new calibration utility that is versatile enough to be used for a wide variety of inspection systems. It allows us to ensure that the key imaging parameters on each tool are within a defined range which guarantees that the images produced by various tools are sufficiently similar and that the algorithm will perform as qualified. This also simplifies recipe management/portability across the fleet, allowing recipes created on one calibrated tool to be used on any other calibrated tool. This work covers a variety of multidisciplinary material including the calibration tray concept/design, key imaging parameters, user interface layout/design, as well as a variety of computer vision algorithms used to extract and examine the different regions of the calibration tray.