2-14.Masking Defects
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.
2-26.TTV 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.
5-4 SiC Semiconductor Crystal Growth As of this writing, much of the outstanding theoretical promise of SiC electronics highlighted in the previous section has largely gone unrealized. A brief historical examination quickly shows that serious shortcomings in SiC semiconductor material manufacturability and quality have greatly hindered the development [...]
2-10.Cracks 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 [...]
5-4-4-3 SiC Epilayer Doping In-situ doping during CVD epitaxial growth is primarily accomplished through the introduction of nitrogen (usually) for n-type and aluminum (usually trimethyl- or triethylaluminum) for p-type epilayers . Some alternative dopants such as phosphorus and boron have also been investigated for the [...]
2-18.Grain boundaries They are interfaces where crystals of different orientations meet. A grain boundary is a single-phase interface, with crystals on each side of the boundary being identical except in orientation. The term “crystallite boundary” is sometimes, though rarely, used. Grain boundary areas contain those [...]
2-28.WARP Warp is the difference between the maximum and the minimum distances of the median surface of a free, un-clamped wafer from the reference plane defined above. This definition follows ASTM F657, and ASTM F1390,which deviation from a plane of a slice or wafer centerline [...]
