Any foreign matter on the surface in localized areas which is revealed under high intensity (or diffuse) illumination as discolored, mottled, or cloudy appearance resulting from smudges, stains or water spots.
A fracture or cleavage of the wafer that extends from the frontside surface of the wafer to the back-side surface of the wafer. Cracks must exceed 0.010” in length under high intensity illumination in order to discriminate fracture lines from allowable crystalline striations. Fracture lines typically exhibit sharp, thin lines of propagation,which discriminate them from material striations.
Any edge anomalies (including wafer saw exit marks) in excess of 1.0 mm in either radial depth or width. As viewed under diffuse illumination, edge chips are determined as unintentionally missing material from the edge of the wafer.
The outer annulus of the wafer is designated as wafer handling area and is excluded from surface nish criteria (such as scratches, pits, haze, contamination, craters,dimples, grooves, mounds, orange peel and saw marks). This annulus is 2 mm for 76.2 mm substrates, and 3 mm for 100.0 mm substrates.
Hexagonal shaped platelets on the surface of the wafer which appear silver in color to the unaided eye, under diffuse illumination.
also referred to as “Mound” When one defect prevents the detection of another defect, the undetected defect is called the masked defect. A distinct raised area above the wafer frontside surface as viewed with diffuse illumination.
Visually detectable surface roughening when viewed under diffuse illumination.
Individual distinguishable surface anomalies, which appears as a depression in the wafer surface with a lengthto-width ratio less than 5 to 1, and visible under high intensity illumination.