PATTERN-MATCHING FOR AUTOMATED E-BEAM TESTING

Pattern matching between the LSI mask layout database and SEM image is essential for automated e-beam testing. Techniques for calibrating wiring width, compensating for layer misalignment, and generating template images taking into account the effect of passivation films have been developed. We combined these techniques with projection edge extraction correlation (PEC) and had registered wiring probed automatically. Positioning time, which includes stage movement, SEM image acquisition, and pattern matching, was less than 20 s. Positioning accuracy (3sigma) was 0.19 mum for metal and 0.55 mum for passivated wiring of an IC with a 2-mum minimum wiring width.