Knowledge

5-2-2-1 SiC Crystallography: Important Polytypes and Definitions

5-2-2-1 SiC Crystallography: Important Polytypes and Definitions Silicon carbide occurs in many different crystal structures, called polytypes. A more comprehensive introduction to SiC crystallography and polytypism can be found in Reference 9. Despite the fact that all SiC polytypes chemically consist of 50% carbon atoms covalently bonded with 50% silicon atoms, each SiC [...]

5-2-2-2 SiC Semiconductor Electrical 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 given in Table 5.1. Much [...]

5-3 Applications and Benefits of SiC Electronics

5-3 Applications and Benefits of SiC Electronics Two of the most beneficial advantages that SiC-based electronics offer are in the areas of high-temperature and high-power device operation. The specific SiC device physics that enables high-temperature and high-power capabilities will be examined first, by several examples of revolutionary system-level performance improvements these enhanced capabilities [...]

5-3-1 High-Temperature Device Operation

5-3-1 High-Temperature Device Operation The wide bandgap energy and low intrinsic carrier concentration of SiC allow SiC to maintain semiconductor behavior at much higher temperatures than silicon, which in turn permits SiC semiconductor device functionality at much higher temperatures than silicon . As discussed in basic semiconductor electronic device physics textbooks, semiconductor electronic [...]

5-3-2 High-Power Device Operation

5-3-2 High-Power Device Operation The high breakdown field and high thermal conductivity of SiC coupled with high operational junction temperatures theoretically permit extremely high-power densities and efficiencies to be realized in SiC devices. The high breakdown field of SiC relative to silicon enables the blocking voltage region of a power device to be [...]

5-3-3 System Benefits of High-Power High-Temperature SiC Devices

5-3-3 System Benefits of High-Power High-Temperature SiC Devices Uncooled operation of high-temperature and high-power SiC electronics would enable revolutionary improvements to aerospace systems. Replacement of hydraulic controls and auxiliary power units with distributed “smart” electromechanical controls capable of harsh ambient operation will enable substantial jet-aircraft weight savings, reduced maintenance, reduced pollution, higher fuel [...]

5-4 SiC Semiconductor Crystal Growth

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 of SiC semiconductor electronics. From [...]

5-4-1 Historical Lack of SiC Wafers

5-4-1 Historical Lack of SiC Wafers Reproducible wafers of reasonable consistency, size, quality, and availability are a prerequisite for commercial mass production of semiconductor electronics. Many semiconductor materials can be melted and reproducibly recrystallized into large single crystals with the aid of a seed crystal, such as in the Czochralski method employed in [...]

5-4-2 Growth of 3C-SiC on Large-Area (Silicon) Substrates

5-4-2 Growth of 3C-SiC on Large-Area (Silicon) Substrates Despite the absence of SiC substrates, the potential benefits of SiC hostile-environment electronics nevertheless drove modest research efforts aimed at obtaining SiC in a manufacturable wafer form.Toward this end, the heteroepitaxial growth of single-crystal SiC layers on top of large-area siliconsubstrates was [...]

5-4-3 Growth of Hexagonal Polytype SiC Wafers

5-4-3 Growth of Hexagonal Polytype SiC Wafers In the late 1970s, Tairov and Tzvetkov established the basic principles of a modified seeded sublimation growth process for growth of 6H-SiC. This process, also referred to as the modified Lely process,was a breakthrough for SiC in that it offered the first possibility [...]