SILICON CARBIDE (SiC) materials are currently metamorphosing from research and development into a market driven manufacturing product. SiC substrates are currently used as the base for a large fraction of the world production of green, blue, and ultraviolet light-emitting diodes (LEDs). Emerging markets for SiC homoepitaxy include high-power switching devices and microwave devices for S and X band . Applications for heteroepitaxial GaN-based structures on SiC substrates include LEDs and microwave devices. These exciting device results stem primarily from the exploitation of the unique electrical and thermophysical properties offered by SiC compared to Si and GaAs. Among these are: a large bandgap for high-temperature operation and radiation resistance; high critical breakdown field for high-power output; high saturated electron velocity for high-frequency operation; significantly higher thermal conductivity for thermal management of high-power devices.
5-2-1 SiC Material Properties
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 [...]
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, [...]
2-1.Wafer Diameter The linear distance across the surface of a circular slice which contains the slice center and excludes any flats or other peripheral fiduciary areas. Standard silicon wafer diameters are: 25.4mm (1″), 50.4mm (2″), 76.2mm (3″), 100mm (4″), 125mm(5″), 150mm (6″), 200mm (8″), and [...]
3-9. Comet Tails Comet tails have a discrete head and trailing tail. These features are aligned parallel to the major at. Usually, all comet tails tend to be of the same length. Count once per occurrence. Two comet tails within 200 microns count as [...]
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 [...]
5-6-5 SiC MicroElectromechanical Systems (MEMS) and Sensors As described in Hesketh’s chapter on micromachining in this book, the development and use of siliconbased MEMS continues to expand. While the previous sections of this chapter have centered on the use of SiC for traditional semiconductor electronic [...]