Direct measurement of copper electrochemical deposition process chemistry as a function of bath life

This paper summarizes the use of quantitative mass spectrometry for the direct measurement of inorganic and organic species associated with copper ECD process chemistries. This capability enables real-time direct measurement of changes in suppressor, accelerator and leveler concentration, as well as copper and chloride, as they occur. It also enables the identification and quantitation of the molecular species resulting from breakdown of the organic additives as a copper ECD bath is operated in production. In all cases, organic breakdown species accumulate in the bath, adversely affecting bath quality.