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.
5-7-1 Future Tied to Material Issues The previous sections of this chapter have already highlighted major known technical obstacles and immaturities that are largely responsible for hindered SiC device capability. In the most general terms, these obstacles boil down to a handful of key fundamental [...]
2-35.Prime Grade Prime Grade:The highest grade of a silicon carbide wafer. SEMI indicates the bulk, surface, and physical properties required to label silicon carbide wafers as “Prime Wafers”.
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 [...]
5-6-1 SiC Optoelectronic Devices The wide bandgap of SiC is useful for realizing short-wavelength blue and ultraviolet (UV) optoelectronics. 6H-SiC-based pn junction light-emitting diodes (LEDs) were the first semiconductor devices to cover the blue portion of the visible color spectrum, and became the first SiC-based devices to [...]
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 [...]
3-1. Large Point Defects Defects which exhibit a clear shape to the unassisted eye and are > 50 microns across. These features include spikes, adherent particles, chips and craters. Large point defects less than 3 mm apart count as one defect.
