Novel submicron infrared microspectroscopy for failure analysis of semiconductor devices

January 10, 2024 2 min read

Novel submicron infrared microspectroscopy for failure analysis of semiconductor devices

High resolution chemical imaging of failed device features

With the O-PTIR technique, several components can be spectroscopically separated and identified. Here, the top 3µm of the dark contamination has been identified as an epoxy component, which is usually the organic binder component in underfill materials.

The bottom 3µm layer appears to contain significant amounts of carbon and carboxylates; the latter may have originated from oxidized cellulosic matter.   Such unprecedented details provide investigative insights into tracking down the source of the contamination, raw materials, or errors in the process. In contrast, conventional FT-IR microspectroscopy could not provide meaningful information from the same specimen.



Finally, the analysis was achieved from a cross-sectioned surface using standard chemo-mechanically polishing processes, representing a significant time savings over more involved sample preparation techniques, such as those requiring labor-intensive focused ion beam (FIB)-based thin sectioning.

 

Overview of additional examples of sub-micron IR failure analysis applications

Left; visible image showing location of 6µm defect, Upper Right; Comparison of unknown O-PTIR spectrum to nearest library match, Lower Right: Comparison of unknown Raman spectrum to nearest library match.

 

Upper Left; Schematic representation of sample and measurement, Lower Left; Visible camera image of defect, Right; O-PTIR spectra from on and off the defect. Colors correspond to markers on visible image

 

Simultaneous IR+Raman spectral searching with 2D search result representation with KnowItAll®

One of the goals of any FA process is the chemical identification of the unknown material and to that end, the final step, after spectral acquisition is to search against a spectral database. Traditionally IR spectra would be searched against an IR spectral library and Raman spectral would be searched, separately, against a Raman spectral library. The user would then examine the two separate so-called “hitlists” for IR and Raman spectra.

Now, with the advent of simultaneous submicron IR+Raman spectral acquisition, as seen in figure here, not only are the IR and Raman spectra simultaneously collected, but now the spectral search of both IR and Raman spectral occurs simultaneously, with a single click from the data acquisition software.

 

Systems for Research (SFR) is your resource and companion for Photothermal Spectroscopy Corp. all across Canada. Together, we are making sure to provide submicron spatial resolution for IR and transmission-like FTIR quality spectra in non-contact reflection mode accessible to all.