A killer defect has the size, type and location to break a circuit: a particle bridging two lines, a void in a via, a pattern break. Inspection tools see far more defects than kill, so yield engineers estimate a kill ratio for each defect class, the fraction that end up as failing die, by overlaying defect maps on bin maps. Whether a defect kills depends heavily on its size relative to the feature spacing at that layer.
Most of those adders are nuisance, but the big particles on metal 2 are killers. Kill ratio's running near 60 percent.
Also heard as
- killer
- yield killer
Related terms
Defect density
Number of yield-killing defects per unit area of wafer or panel, the main input to yield models.
Yield
Fraction of units that come out good at a step or across a whole process, the headline number for any production line.
Wafer map
Picture of a wafer showing each die's test result or measurement by location, used to spot spatial failure patterns.
Excursion
Sudden departure of yield, defect counts or a key parameter from its normal band, big enough to trigger holds and an investigation.