In recent years, laser reflectance modulation measurements are widely used in failure analysis. Among them, EOFM (Electron-Optical Frequency Mapping) technique is easy to operate and very practical. In this article, some images with abnormal EOFM phenomena and their corresponding defects are showing up, the causes of those abnormal EOFM phenomena are also pointed out. They prove that EOFM function is very effective for discovering open or high-impedance defects on metal trace and pinpointing short-circuit defects. In addition to the two aspects above, there are also some abnormal EOFM phenomena we couldn’t explain perfectly. We studied one of them and proposed two possible causes of the anomaly. After simulation experiment and calculation, it could be basically determined that the abnormal EOFM phenomenon was caused by the substrate noise current.

Due to the decreasing metal line size on complicated integrated circuit, non-destructive analysis strategy such as EMMI (Emission Microscope) is very significant to failure analysis, especially when special cold temperature failures are encountered. When combined with efficient schematic and layout analysis, the real defect can be localized without much microprobe work.

Die attach is well known in die bonding process. Its electrical character is simple. But some failures caused by die attach are not so simple. And it is not proper to analyze by a generic analysis flow. The analysis of two failures caused by die attach are presented in this paper.