Abstract
Integrated circuit (IC) delayering is highly subjective, as operators must make process decisions based on minute details observed in optical images of the ICs. Process decisions have a strong influence on the quality of the final sample, with the result being highly dependent on an operator’s technique, skill, and experience. However, end point detection, process development, and in-process feedback all benefit from a quantitative method to evaluate results. To this end, a quality metric for IC delayering based solely on optical images has been developed. The optical images are processed into CIE-Lab color space, candidate zones are established, and color homogeneity both within and among these zones is calculated, which contribute to a final die quality score. The work done in this study takes a significant step forward in quantifying IC delayering results, which is critical for improving repeatability, reproducibility, and developing automation frameworks in these workflows.