Comparison of Elemental Detection Using Microcalorimetry, SIMS, AES and EDS (SEM, STEM, and TEM)

Cu contamination has become a larger concern as more semiconductor fabrication facilities switch from aluminum to Cu interconnects. The resolution limits of several analytical tools are compared to determine the optimum analysis methods for detecting Cu contamination in semiconductor materials. The elemental detection limits of Secondary Ion Mass Spectrometry (SIMS), Auger Electron Spectrometry (AES), Microcalorimetry and Energy Dispersive Spectrometry (EDS) systems on Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and Transmission Electron Microscopy (TEM) instruments are evaluated for Cu in WSix.Two different samples were used in this study. One sample has a high uniform concentration (0.9% atomic, 0.7 wt.%) of Cu that was incorporated during the sputter deposition of WSi2. A lower concentration was ion implanted with 63Cu to a dose of lel4 cm-2 and has a peak concentration of lel9 cm"3, or 0.02% atomic.