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Silicon carbide chips are predicted to experience rapid expansion over the coming decade as key components in electric vehicles, charging stations and electrical power utilities. But ramping up production can sometimes prove challenging.

Wolfspeed, STMicroelectronics and Allegro MicroSystems all reported issues related to SiC production on their earnings releases this week and consequently saw their stocks fall significantly as a result.

1. Alpha Carbide

Silicon carbide is a hard material with a Mohs scale rating of 9.5, second only to diamond. It boasts high compressive and tensile strength, excellent chemical stability and low thermal expansion coefficient that makes it suitable for wear-resistant and cut-resistant applications as well as good mechanical properties and an extremely high melting point that make it relatively resistant to heat and oxidation.

Grinding wheels and cutting tools often use this versatile material, often to produce grinding wheels with polished wheels for use on stone, glass, ceramics, cast iron and nonferrous metals. In addition, it’s often chosen as the go-to material when cutting and polishing high temperature materials like tungsten and rhenium.

Silicon carbide comes in both black and green varieties; both varieties of alpha silicon carbide (a-SiC). Both forms are commonly used in industrial settings as they offer lower costs compared to its higher-grade sintered version. Alpha SiC features hexagonal crystal structure similar to that of wurtzite; formation occurs at temperatures above 1700 degC; toughness surpasses that of boron carbide and it possesses superior chemical resistance.

Beta silicon carbide (b-SiC) is a form of silicon carbide with cubic crystal structure, making it suitable for sintering into various shapes via methods such as dry press, hot isostatic press or injection molding. These characteristics allow it to be formed into intricate designs without compromising strength or durability. So it is an ideal material for high-temperature, wear-resistant applications like classifier and crusher parts, spray and blasting nozzles and heat-resistant components such as metal-melting crucibles and electric furnaces. Furthermore, silicon carbide power semiconductors have become the material of choice in hybrid electric vehicles to increase fuel efficiency while decreasing battery cooling systems complexity.

2. Beta Carbide

Silicon carbide is one of the hardest materials on Earth and requires diamond-tipped blades to cut it. Found naturally as moissanite mineral deposits but more frequently manufactured synthetically. A wide-bandgap semiconductor capable of operating at higher temperatures and voltages than silicon or germanium semiconductors, silicon carbide makes an excellent material choice for power electronic devices such as light emitting diodes (LEDs).

GNPGraystar’s beta sic is an innovative form of SiC with a cubic crystal structure similar to zinc blende. This ceramic material offers excellent chemical stability, high thermal conductivity, low thermal expansion coefficient, wide band gap gap opening frequency, electro drift velocity and electronic mobility properties that make it suitable for electronics industry, precision machining applications as well as military/aerospace use, high grade refractories and special ceramic applications.

Beta-SiC’s crystalline structure makes it a highly resilient material, capable of withstanding abrasion, impact, and heat damage. Due to this property it has long been utilized as ballistic protection against moderate and heavy threats as well as serving many other industrial uses including grinding, cutting and polishing applications.

beta-SiC stands out from alpha silicon carbide by having a much lower density, making it suitable for use in abrasive applications without harming either tool or workpiece. Furthermore, due to its high melting point and hardness characteristics, it can easily fuse or be fused together with materials like metals and plastics, making it an attractive material for cutting and grinding operations. Furthermore, it has great potential in high voltage battery management systems in electric vehicles; with its potential to improve charging efficiency while decreasing energy consumption and costs; potentially expanding vehicle range while simultaneously reducing their size/cost as well.

3. N-Type

Silicon is long been the go-to material in electronics manufacturing, but that may soon change. Wide-bandgap semiconductor silicon carbide (SiC) has emerged as a formidable rival and its use in power semiconductor markets is growing. SiC chips offer advantages over silicon in terms of higher efficiency and lower voltages as well as smaller component designs that improve energy efficiency while decreasing cooling requirements.

Silicon carbide’s most prevalent application in 2021 was power semiconductors, with more than 75% market share accounting for their use in power semiconductors. Their wider band gap makes SiC ideal for high-speed and power switching applications such as inverters, on-board chargers, DC-DC converters, hybrid electric vehicle powertrains and energy recovery systems. Furthermore, their energy saving properties allow drivers to extend driving range per charge whilst shortening charging times and improving fuel economy – further making silicon carbide semiconductors the material.

As demand for SiC has surged, several companies have announced large investments. Wolfspeed announced in March the opening of the John Palmour Manufacturing Center for Silicon Carbide in Durham, North Carolina which will produce 200mm (8-inch) wafers – nearly twice the size of traditional 6-inch wafers – to meet production increases needed to support manufacturing of power devices and other high-speed semiconductors made with SiC.

Nonintrinsic silicon carbide is the most widespread compound semiconductor material, boasting more than 200 varieties based on layer structure repetition pattern and other factors. While pure silicon is naturally occurring and easy to work with, N-type silicon carbide requires doping with elements such as phosphorus or arsenic to become useful as a semiconductor, as this will supply electrons necessary for conducting electricity through it.

4. P-Type

P-type silicon carbide semiconductors have become an excellent replacement for traditional silicon. Due to its wide band gap, P-type silicon carbide can operate at higher temperatures and switching frequencies while simultaneously reducing power loss at high voltages – making it an excellent choice for use in electric vehicle (EV) power components such as inverters, chargers and auxiliary loads.

But the rising demand for power devices made from silicon carbide is driving its widespread deployment within industry, driving global market size of silicon carbide power devices to grow significantly over recent years and expected to continue doing so post-2024 as investment continues in various projects.

P-type silicon carbide (SiC), unlike its more prevalent N-type variant, which uses boron as its main constituent element, contains more light-resistant phosphorus atoms which result in longer carrier lifetime in solar panels – this benefit alone has made P-type SiC production attractive to many manufacturers in recent years.

Bosch recently announced it would begin production of SiC chips at its facility in Roseville, California using existing clean rooms and skilled workforce; however, to accommodate more complex processing required by silicon carbide processing equipment had to be retrofitted into the plant.

Wolfspeed’s plant will specialize in manufacturing 200mm (8-inch) wafers that are 1.7 times larger than standard 150mm (6-inch) wafers and will enable production of power semiconductors for electric vehicle (EV), 5G communications, and artificial intelligence applications. Furthermore, this facility will have capacity for producing SiC MOSFET transistors – further strengthening their competitive edge.

5. 10 inches & above

Silicon Carbide (SiC) semiconductors have become an increasingly popular choice across various applications worldwide. One notable use for SiC semiconductors lies within the electric vehicle industry where their efficient energy processing provides reduced energy loss and quicker recharging times. Furthermore, SiC technology helps improve battery control safety measures as well as providing greater battery protection.

SiC’s wider bandgap allows it to handle higher voltages and temperatures than silicon. A bandgap refers to the energy gap required for electrons to travel from an atom’s valence band into its conduction band; conductors typically possess narrow bandgaps while insulators have larger ones; devices operating at higher voltages and temperatures as well as greater power densities can benefit from these wider gaps.

SiC can extend a vehicle’s driving range by improving the efficiency of its inverter system – which converts DC power from batteries into AC current for running motors – with its high switching speed aiding fast charging processes necessary for BEVs. Furthermore, SiC reduces both size and weight of battery management systems, cutting costs associated with an EV purchase.

Government pressure for lower emissions, combined with BEV popularity, is driving silicon carbide and other wide-bandgap technologies into mainstream use. As part of this movement, Wolfspeed, one of the top producers of base SiC wafers, is at the forefront and soon upgrading their Roseville facility to produce 200mm wafers while employing MTI Instruments Proforma 300iSA defect inspection system to increase yield while decreasing costs.

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