Controlling Copper ECD Processes by Early Fault Detection and Diagnosis Using In-situ Electrochemical Sensor Coupled with Pattern Recognition Chemometrics

摘要

A system for plating bath process control was developed utilizing a novel approach that combines advanced electroanalytical methods with various statistical data analysis techniques based on chemometric factor analysis. The electroanalytical techniques employed, including DC- and AC-voltammetry, were designed to provide a response strongly affected by the presence of specific contaminants while being practically insensitive to the varying concentrations of deliberately added bath constituents. The shape differences between deformed and training set voltammograms were quantified using various outlier-detection chemometric techniques. The specificity of the response to the presence of a likely contaminant combined with multi-parameter quantification of its presence enabled not only early-fault detection but also its diagnosis, therefore automating the troubleshooting process.