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 containing both concave and convex regions.
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 [...]
5-4-4-1 SiC Epitaxial Growth Processes An interesting variety of SiC epitaxial growth methodologies, ranging from liquid-phase epitaxy, molecular beam epitaxy, and chemical vapor deposition(CVD) have been investigated . The CVD growth technique is generally accepted as the most promising method for attaining epilayer reproducibility, quality, [...]
5-2-2-2 SiC Semiconductor Electrical Properties Owing to the differing arrangement of Si and C atoms within the SiC crystal lattice, each SiC polytype exhibits unique fundamental electrical and optical properties. Some of the more important semiconductor electrical properties of the 3C, 4H, and 6H SiC polytypes are [...]
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”.
5-6-4-1-2 Bipolar and Hybrid Power Rectifiers For higher voltage applications, bipolar minority carrier charge injection (i.e., conductivity modulation) should enable SiC pn diodes to carry higher current densities than unipolar Schottky diodes whose drift regions conduct solely using dopant-atom majority carriers . Consistent with silicon [...]
5-5-2 SiC-Selective Doping: Ion Implantation The fact that diffusion coefficients of most SiC dopants are negligibly small (at 1800°C) is excellent for maintaining device junction stability, because dopants do not undesirably diffuse as the device is operated long term at high temperatures. Unfortunately, this characteristic also largely [...]
