Photon Emission Microscopy (PEM) is a failure analysis technique that detects faint photons emitted by semiconductor devices during operation — arising from hot carrier effects, avalanche breakdown, or oxide breakdown, enabling precise localization of defect sites.

What Is PEM?

• Emission Sources: Hot carrier luminescence, avalanche multiplication, forward-biased junction recombination, oxide breakdown.
• Detection: InGaAs camera (900-1700 nm) or cooled CCD (visible-NIR).
• Modes: Static (continuous bias), Dynamic (time-resolved to specific clock edges).
• Through-Silicon: NIR photons penetrate Si, enabling backside imaging through thinned substrates.

Why It Matters

• Defect Localization: Directly pinpoints the failing transistor or gate.
• Latch-Up Detection: Clear bright emission from parasitic SCR triggering.
• Non-Destructive: The device is operating normally during analysis.

Photon Emission Microscopy is catching chips glowing in the dark — using the faintest light emissions to reveal exactly where defects hide.