Analysis of copper plating baths

Recent industry announcements concerning the planned use of copper wiring on semiconductor devices sets the stage for increased industry requirements for monitoring and optimization of copper plating baths used in the manufacture of these devices. Although plating, or electrochemical deposition (ECD) as it is called in the semiconductor industry, is not a new technology, the requirements for deposition precision and quality are by far more critical than that currently practiced in other industries. Ion and metal-free liquid chromatography provide the analytical capabilities to monitor plating and etch bath components, contaminants, and degradation products to help optimize the process and reduce the amount of waste. Some typical applications using ion and metal-free liquid chromatography for the analysis of plating and etch baths are: (1) additive concentration determination; (2) individual component analysis; (3) contaminant analysis. In this presentation, we discuss: (1) the determination of the concentration of an additive to a copper plating bath; (2) how ion and metal free liquid chromatography can monitor and optimize the relative “goodness” of a plating bath; (3) two typical chromatography applications for plating and etch baths: (a) analysis of organic additives; (b) analysis of trace chloride