Raman Spectroscopy and Hyperspectral Imaging for Wafer-On-Wafer (WOW) Processing

The application of Raman spectroscopy to the silicon device manufacturing process was investigated for the first time. Confocal Raman imaging is a non-contact, non-destructive technique, which can be used for 3D-imaging of semiconductors. The depth resolution is particularly important for stacked devices, such as wafer-on-wafer. Further, Raman can visualize residual stress in the devices, which influences reliability of the final chip. Organic residues and contaminants are easily identified in the Raman spectra as well.