Backside FIB/SEM analysis strategy to identify failure mode

Integrated circuits (IC) used in automotive applications must be produced under high quality standards. To achieve this goal each single fail from qualification or also field application must be traced down to its physical failure root cause to increase the overall device reliability. In most cases the failure analysis (FA) strategy of IC related defects is straight forward by electrical testing, followed by defect localization and finally destructive physical analysis to identify the defect structure and derive the root cause of the electrical malfunction.

In some cases, such a strategy is not appropriate, especially if the failure site cannot be exactly located or if the IC-package interaction causes the failure mode. In this session a failure root cause analysis of an automotive magnetic field sensor which fails by a simple electrical short between two metal layers will be demonstrated. At this specific failure mode, the original root cause could not be identified from frontside despite many trials, that’s why it was decided to turn the preparation starting from backside without removing the package at the frontside.

This backside analysis strategy to identify a package related failure mode at an automotive magnetic sensor device is explained in this session.