High Temperature Devices Based Upon Silicon Carbide Joshua Banister 4/7/17 The physical and chemical properties of silicon carbide makes it an ideal choice for the fabrication of wide band gap semiconductors. Electronic subsystems that require temperatures higher than 420℃ coupled with high power operation will include wide band gap devices. Examples of these devices are light emitters, aerospace devices, high power microwave devices, micro-electromechanical system (MEMS) technology, and substrates.
Outline General Info Device Benefits Intrinsic Carriers Video Summary References 5 Concepts
General Info High-temp devices operate at temperatures higher than 450 ℃ The combination of silicon and carbon allow for high temperatures and therefore higher performance in devices Electrons in SiC require more energy to be pushed into the conduction band, which allows the material to withstand about 10 times the maximum of silicon If temperatures become too high, it can result in p-n junction leakage and thermionic leakage
Devices Used in hybrid vehicles to reduce the size of liquid cooling systems Photovoltaic panels need inverters to convert the DC from AC electricity for the power grid Other Popular wide band gap materials Some of the premier wide band gap devices materials: Silicon carbide (SIC) Aluminum nitride (AlN) Gallium nitride (GaN) Boron nitride (BN) Diamond Zinc selenium (ZnSe)
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Device Benefits Commercial availability of substrates Ability to grow a thermal oxide for use as masks in processing device passivation layers and gate dielectrics SiC’s wide bandgap also makes it more heat resistant than silicon Silicon-based inverters lose 2 to 3 percent of their energy in photovoltaic panels. Inverters containing SiC diodes and transistors can cut that loss in half
Intrinsic Carriers If intrinsic carriers density becomes comparable to dopant density, it can have negative effects on conductivity The concentration of these carriers relies upon the temperature and band gap of the material, which can also have effects on a material's conductivity
Video https://www.youtube.com/watch?v=9FGSOK5 l6s0
Summary & Conclusions SiC is a significantly better choice than regular silicon due to a higher quantity of electrons to be pushed into the conduction band This allows a higher heat resistivity and allows devices to operate faster It has the ability to grow a thermal oxide for use as masks in processing device passivation layers and gate dielectrics
References https://www.researchgate.net/publication/227312758_Silicon_carbi de_and_diamond_for_high_temperature_device_applications http://pveducation.org/pvcdrom/pn-junctions/intrinsic-carrier- concentration https://www.youtube.com/watch?v=9FGSOK5l6s0 https://encrypted- tbn3.gstatic.com/images?q=tbn:ANd9GcTjhpWQDH0GLYsrGBaJpCY3 mM5hIPpDSFQamTtMAfbKU5dnJ0Av4A https://e- rocks.com/sites/erocks/files/styles/main_image_550x550/public/it em-images/756/2015-04-22/Silicon-Carbide-Man-Made- ADMN193184-01.jpg?itok=Is-SAKN9 http://spectrum.ieee.org/semiconductors/materials/silicon- carbide-smaller-faster-tougher
5 Key Concepts High-temp devices operate at temperatures higher than 450 ℃ If temperatures become too high, it can result in p-n junction leakage SiC allows a higher amount of electrons to be pushed into the conduction band Has the ability to grow a thermal oxide for use as masks in processing device passivation layers and gate dielectrics Intrinsic carrier concentration directly affect the conductivity