Evaluation of hotspots EPE propagation through step-by-step SEM contour analysis

In a HVM, pinpointing process issues is crucial, as it directly affects product quality and production efficiency. Accurate fault localization helps teams quickly identify potential process defects, avoiding resource waste and time delays. However, troubleshooting process problems typically relies on indirect data analysis. Teams collect and monitor changes in various parameters, such as recipe parameters, environmental variations, and equipment differences, to infer possible root causes. This article proposes a direct troubleshooting method based on contour and statistical analysis. By directly comparing the graphical differences between different step processes and analyzing changes in Critical Dimension (CD) distribution, it is possible to pinpoint issues from overall process variations to specific changes caused by individual step processes. This approach shortens the troubleshooting steps and reduces the time needed to resolve problems. Additionally, because it goes beyond simple variation comparison and quantifies it using CD values, it allows for the disaggregation of localized variation amounts within the dimensions of SEM images. Therefore, this method not only reduces the number of inspection sites for troubleshooting but also provides insights into the degree of deterioration between each site, facilitating quicker problem resolution.