Application of glow discharge mass spectrometry for direct trace impurity analysis in Cu films

An application of glow discharge mass spectrometry (GDMS) for determining the trace impurities in Cu films has been examined. GDMS has a little difficulty to apply to thin films because of the accompanying non-conducting substrate and the thin film thickness. To electrify the film deposited on the non-conducting substrate, we have used an aluminum foil to cover the edge of the Cu film in order to make an electrical contact. Additionally, to obtain the depth profile for the trace impurities in the film, we have utilized a Cu bulk in advance to provide an optimum condition for the analysis and have replaced with a Cu film to start the GDMS analysis promptly with the optimum condition. As a result, we could obtain results with trace multi-impurities analysis and the depth profile without the loss of the film surface by sputtering for optimizing condition, which presented some available information about the thin film characterization.