Metal contamination control and reduction in plasma etching

For the IC chip production, the control and reduction of the tracing metal contamination (MC) [1] is always the vital for the quality control in the plasma dry etching process. The present work investigated the impacts of the plasma chemistry and process conditions on the creation, control and reduction of the tracing MC in plasma etching. It was found that the MC can be induced from the chamber materials, from the stocked materials on the wafer, and from the plasma chemistry (or etching process). Especially, the MC level is often limited below E10 atom/cm
²
in some key plasma processes and thus the in-situ reduction of MC either inside the brand new etching chamber or during the plasma etching process is required. In this study, the actual MC in one brand new plasma chamber is correctly diagnosed and then the MC level is reduced and controlled through the developed plasma etching procedure. The developed procedure BKM has been successfully applied to support the qualification on the established etching tools on the Fab.