2.Definition of Dimensional Properties,Terminology and Methods of Silicon Carbide Wafer

2-11.Edge Chips

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.

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2-12.Edge Exclusion

2-12.Edge Exclusion 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 [...]

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2-13.Hex Plate

2-13.Hex Plate Hexagonal shaped platelets on the surface of the wafer which appear silver in color to the unaided eye, under diffuse illumination.  

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2-14.Masking Defects

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.  

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2-15.Orange Peel

2-15.Orange Peel Visually detectable surface roughening when viewed under diffuse illumination.  

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2-16.Pits

2-16.Pits 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.  

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2-17.Polytypes

2-17.Polytypes Many compound materials exhibit polymorphism, that is they can exist in different structures called polymorphs. Silicon carbide (SiC) is unique in this regard as more than 250 polymorphs of silicon carbide had been identified by 2006,with some of them having a lattice constant as long as 301.5 nm, about [...]

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2-18.Grain boundaries

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 atoms that have been perturbed [...]

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2-19.Scratches

2-19.Scratches A scratch is dened 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.  

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2-20.Linear Crystallographic Defects

2-20.Linear Crystallographic Defects Crystalline solids exhibit a periodic crystal structure. The positions of atoms or molecules occur on repeating fixed distances, determined by the unit cell parameters. However, the arrangement of atom or molecules in most crystalline materials is not perfect. The regular patterns are interrupted by crystallographic defects Striations [...]

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