Cree, once best-known for their LED lights, has now shifted focus exclusively towards wide bandgap silicon carbide and gallium nitride semiconductors. [1]
Durham-based materials supplier and chip manufacturer now offers 4-inch SiC substrates and epitaxy material commercially, building on research funded by the Air Force. Their wider format enables double the number of devices per wafer when compared to 3-inch versions.
Högspänning
Cree, a company known for specialized wide bandgap semiconductors (SiC), has recently introduced their inaugural silicon carbide power MOSFET. As part of their Wolfspeed power device family, this MOSFET boasts high blocking voltage with lower switching losses for improved energy efficiency and smaller size.
Silicon devices cannot operate reliably at high temperatures and frequencies up to five times faster, with less switching loss, making them suitable for more demanding applications such as electric vehicles (EVs), onboard chargers, buck converters and main drive inverters that need high blocking voltages to safely transfer energy from battery to wheels.
John Palmour, CTO at Cree/Wolfspeed, discusses the differences between silicon and SiC and why both materials are being implemented into new power electronic designs, and where future applications might exist.
Cree and SUNY Poly are partners in the Mohawk Valley Fab, an ambitious $5 billion project which will become the world’s largest manufacturing campus devoted to silicon carbide materials. It will produce SiC wafers used by other companies that produce power electronics that convert energy stored in batteries into electricity; ultimately moving us away from fossil fuels towards clean-energy economies such as electric vehicles with fast charging capabilities as well as onboard chargers used by these vehicles, boost and PFC converters used in data centers, industrial motor drives, 5G wireless infrastructure.
High Current
Silicon carbide devices feature a wider bandgap that enables them to operate at higher voltages, power levels and frequencies than their silicon (Si) counterparts, enabling components to be smaller, lighter and more energy efficient – cutting both costs and heat dissipation costs while increasing efficiency by switching rapidly at high temperatures and speeds while decreasing noise pollution without the need for fans.
Silicon carbide’s high blocking voltages make it an excellent material choice for power switching applications, such as MOSFETs and diodes with superior breakdown field strength that enable them to switch at up to three times higher frequencies than commercially available silicon devices, making SiC power devices perfect for industrial motor drives, AC/DC converters for data centers, PFC (power factor correction), boost/buck DC/DC conversion circuits, downhole drilling for the petrochemical industry as well as hybrid and electric vehicle applications.
After years of success manufacturing LED lighting, Cree shifted focus and, in 2022, opened Wolfspeed’s first and world’s largest 200mm power semiconductor fabrication plant in Chatham County near NC State. Their goal is to produce silicon carbide wafers which could significantly improve energy efficiency – potentially cutting electricity consumption and emissions by up to 50 percent – which would enable sustainable clean energy sources like electric vehicles with their chargers, 5G wireless infrastructure, renewables and power storage to transition away from fossil fuels towards more sustainable forms such as electric cars with their chargers, 5G wireless infrastructures as well as power storage capabilities – essential when making transition from fossil fuels over to sustainable forms like electric vehicles with their chargers as a step toward sustainable clean energy sources like electric vehicles and their chargers as the world transitions away from fossil fuels towards renewable sources like electric vehicles with power storage capabilities in order to achieve energy independence over time.
High Temperature
Silicon carbide is an adaptable material, capable of operating in a wide temperature range. This makes it useful in applications involving high voltage and current electronics like semiconductor devices that must endure extreme conditions – silicon carbide is capable of doing this even at higher temperatures than conventional silicon semiconductors, making it an excellent replacement in power transistors that control flow of electricity in electrical circuits – operating at much higher voltage and power levels while being smaller and requiring less cooling than their silicon counterparts.
Silicon carbide offers several distinct advantages that make it a suitable material for power electronics and RF applications, including medium-voltage (3.3kV to 10kV) and high-voltage (2kV to 15kV) semiconductor devices. Cree/Wolfspeed has developed several SiC power device technologies with medium-voltage (3.3kV to 10kV) and high-voltage (2kV to 15kV) applications in development; their work with PowerAmerica, one of 14 DOE-funded manufacturing institutes has expedited development and reliability testing of their SiC power semiconductor products.
Cree/Wolfspeed’s 36 years of experience working with silicon carbide and its successor material gallium nitride (GaN) combined with its vertically integrated technology portfolio spanning wafers and epitaxy as well as power/RF devices make this prediction possible.
Low Leakage
Silicon carbide boasts an exceptionally low leakage current (less than 1A) when compared to other power semiconductor devices, thereby decreasing the risk of system malfunction or system failure and making silicon carbide ideal for high-efficiency power electronics devices operating under extreme temperatures or in harsh environments.
Silicon carbide crystals are made of very hard material that is resistant to shock, vibration and impact damage. This property makes silicon carbide ideal for tools such as hammers, drills and saws that must withstand high speeds or pressure; its toughness also lends itself well for lapidary use as an abrasive, while modern lapidary applications make use of its hardness as an antidistortion measure against surface damage on workpieces.
SiC MOSFETs and diodes increase energy efficiency in many power electronic systems due to their higher blocking voltage and faster switching capabilities, making them three times more energy-efficient than commercially available silicon devices, leading to reduced costs, weight savings and greater space savings for designers.
Wolfspeed (then known as Cree) announced an important partnership agreement with General Motors to supply their electric vehicles with silicon carbide chips from Wolfspeed’s production plant in 2022, becoming a key player as automotive EV ambitions increase significantly. Wolfspeed also stated they planned to upgrade production plant capacity to produce 200-mm wafers to support these orders.
Swedish 
English