Failure Analysis (FA) is the systematic investigation of semiconductor devices that have failed during testing, qualification, or field operation. The goal is to identify the root cause of failure so that corrective actions can be taken to prevent recurrence. FA is one of the most important disciplines in semiconductor quality and reliability engineering.

FA Workflow

• Step 1 — Electrical Characterization: Re-test the failed device to confirm and localize the failure — determine which pins, functions, or operating conditions trigger the defect.
• Step 2 — Non-Destructive Analysis: Use techniques like X-ray imaging, acoustic microscopy (C-SAM), and photon emission microscopy to examine the package and die without damaging them.
• Step 3 — Decapsulation: Carefully remove the package material (using acid, laser, or plasma) to expose the bare die for direct inspection.
• Step 4 — Physical Analysis: Employ SEM (Scanning Electron Microscopy), FIB (Focused Ion Beam) cross-sectioning, TEM imaging, and EDS (Energy Dispersive Spectroscopy) to examine defects at the nanometer scale.
• Step 5 — Root Cause Determination: Correlate physical findings with electrical behavior to determine whether the failure is due to a design issue, process defect, contamination, ESD damage, or wear-out mechanism.

Common Failure Modes Found

• Electromigration voids in metal interconnects
• Gate oxide breakdown or dielectric defects
• Contamination particles causing shorts
• Cracked dies from mechanical stress
• ESD (Electrostatic Discharge) damage

FA capabilities are essential for any serious semiconductor operation — they close the quality loop and drive continuous process improvement.