3-2. Scratches
Grooves or cuts below the surface plane of the wafer having a length-to-width ratio of greater than 5 to 1. Scratches are speci ed by the number of discrete scratches times the total length in fractional diameter.
2-9.(Area) Wafer Contamination 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.
3-4. Step Bunching Step bunching is visible as a pattern of parallel lines running perpendicular to the major at. If present, estimate the % of speci ed area affected.
2-11.Edge Chips 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.
Total Thickness Variation (TTV): The maximum variation in the wafer thickness. Total Thickness Variation is generally determined by measuring the wafer in 5 locations of a cross pattern (not too close to the wafer edge) and calculating the maximum measured difference in thickness. The [...]
5-7 Future of SiC It can be safely predicted that SiC will never displace silicon as the dominant semiconductor used for the manufacture of the vast majority of the world’s electronic chips that are primarily low-voltage digital and analog chips targeted for operation in normal [...]
2-19.Scratches A scratch is dened as a singular cut or groove into the frontside wafer surface with a length-to-width ratio of greater than 5 to 1, and visible under hight intensity illumination.
