4.2.3 Light Emission Microscopy, EMMI
Certain integrated circuit failures emit light that can be imaged using light emission microscopy. This photoemission phenomenon is typically the direct result of recombining electrons and holes, so leakage current is the failure mode in these types of failures. Emission microscopy uses a sensitive camera and powerful image intensification technology to view and capture these optical emissions. The resulting radiation image is then overlaid with its corresponding die surface image, such that the emission spot coincides with the precise location of the defect, allowing device analysts to detect and localize the defects. A typical EMMI photo consists of an overlay of two images: the circuitry and the emission spots.
Figure 7. A typical EMMI-image with the emission spots superimposed over the circuit image.
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Mört & Sääski
