Silicon Carbide Transistor

Silicon carbide (SiC) is an inert chemical compound with properties similar to semiconductors; with carefully chosen impurities added, SiC can be converted to behave like one more easily than traditional silicon. SiC’s wide band gap enables it to move electrical energy more effectively than its silicon counterpart.

SiC transistors offer significant advantages over IGBTs and silicon MOSFETs, including higher blocking voltages, reduced on-state resistance and enhanced temperature performance compared to their counterparts, making power converter solutions previously impossible or impractical possible.

High Breakdown Voltage

Silicon carbide (SiC), with its superior electric field strength, enables power semiconductor devices that deliver much higher voltages than their silicon-based counterparts. This presents multiple benefits that make SiC an attractive choice for next-generation power devices.

One of the primary advantages of power electronic components made with silicon nanowire is their increased tolerance to transient voltage spikes, or stress, without experiencing unpredictable conduction behavior and potentially catastrophic failure. This enables these power electronic components to be rated much higher than their silicon counterparts such as Insulated Gate Bipolar Transistors (IGBTs) and standard power MOSFET devices.

SiC is known for creating devices with much lower on-resistance than their silicon counterparts, due to its high blocking voltage. This is accomplished by taking advantage of fast-switching unipolar devices instead of conventional insulated-gate bipolar transistors (IGBTs) for faster switching frequency and power dissipation resulting in greater energy savings for end users.

SiC MOSFETs also facilitate this feat due to their high current density, which can be increased through use of damaged termination layers that enhance depletion layer contouring and decrease electric fields within their devices. Furthermore, an n-type doped channel region stretching from source region to channel insert facilitates low on-resistance in their devices as well.

SiC power devices feature very thin drift layers, which further help lower on-resistance per unit area. Resistance components of total turn-on resistance are determined by doping concentration and drift layer thickness, so decreasing either can significantly lower overall on-resistance of devices. SiC is an ideal material for creating new generations of power devices that offer unparalleled voltage, current and energy efficiency – such as Schottky diodes, PiN diodes and hybrid IGBT/MOSFETs that deliver impressive voltage, current and energy efficiencies in applications where high voltage/high temperature operation is necessary. This makes SiC an invaluable material when applied to power semiconductor applications requiring operation at higher voltage/temperature conditions.

Low On-Resistance

Silicon carbide is well-known for its hardness and use as an abrasive in manufacturing industrial tools like brake disks for vehicles, automotive lubricants and diamond replacements, but recently has also become an innovative semiconductor material with properties which could unlock new levels of performance within various electronics circuit designs. One such attribute is its capacity for handling extremely high voltages – making it suitable for power electronics applications.

SiC’s critical breakdown electric field strength is approximately 10 times that of traditional silicon technology, making fabrication of SiC MOSFETs with operating voltages reaching 1.5kV possible – far exceeding those achievable with conventional IGBTs or bipolar transistors.

One key attribute of silicon carbide that allows devices constructed out of it to withstand higher voltages is its significantly lower on-resistance than silicon. This enables switching and off at lower current levels, dissipating less heat and improving efficiency.

Silicon carbide transistors boast low on-resistance because their material features extremely high thermal conductivity, enabling it to dissipate heat more effectively than silicon and thus making high voltage applications possible without worrying about heat damage that would compromise their usefulness.

SiC MOSFETs stand out as superior devices due to their faster switching speeds and lower system-level losses; this helps increase energy conversion efficiency at higher frequencies.

Silicon Carbide has revolutionised power electronics with its combination of advantages, providing devices capable of increasing energy efficiency and power density for motor control, converters and power supplies. Wolfspeed offers 1000 V silicon carbide MOSFETs specifically optimized for fast switching applications that make them suitable for electric vehicles (EVs), industrial power supplies, solar energy systems and renewable energy applications.

High Temperature Operation

Power electronics applications often rely on silicon carbide transistors with their high temperature operation capabilities for maximum system efficiency, as this allows designers to operate devices at temperatures, voltages and frequencies that would otherwise be impossible with traditional silicon-based semiconductors. As a result, silicon carbide allows designs with reduced energy loss, higher switching frequencies, reduced overall power dissipation and greater system efficiencies than ever before.

SiC provides exceptional material properties that allow it to fulfill this role, combining high blocking voltage capabilities with low turn-on resistance in a unipolar device, making it suitable for solutions requiring fast switching times in high power environments. Achieving such performance in an unipolar semiconductor also means eliminating IGBTs or bipolar transistors altogether and thus offering considerable benefits to application designers globally.

Silicon carbide’s broad bandgap allows components to run more efficiently at higher operating temperatures. When compared to conventional silicon, which typically features a bandgap of around 1.12eV, silicon carbide boasts more than three-times higher values of around 3.26eV; meaning silicon carbide devices can handle over ten times the power levels, double voltage levels and four times greater frequency compared to their silicon-based counterparts.

Silicon carbide’s high temperature operation makes it suitable for more demanding industrial and transportation applications, where reliability of electrical equipment is of utmost importance. Research into heat-resistant integrated logic circuits made of silicon carbide could enable sensors in jet engines, oil wells, deep space missions and other environments to process data faster and more reliably than traditional devices without long wires that might break or complex cooling mechanisms.

Producing high-quality silicon carbide chips is challenging due to how it crystallizes into multiple polytypes. Producing large single crystal wafers for SiC-based power devices takes considerable effort, yet can be accomplished using advanced atomic layer deposition (ALD) growth processes.

An essential factor in the successful performance of high-temperature SiC devices lies in controlling both their concentration and distribution of impurities, which affect their electro-thermal characteristics as well as breakdown voltage capability. EAG Laboratories has an in-depth knowledge of silicon carbide materials, with expertise in performing both bulk- and spatially resolved analytic techniques to verify proper dopant concentration/distribution to achieve maximum device performance.

Low Switching Losses

Silicon Carbide (SiC) is an emerging wide bandgap semiconductor material being considered as an alternative to silicon devices for power electronics applications, particularly power converters and instruments used by electric vehicles or space exploration probes (Mantooth, Zetterling and Rusu). SiC’s wide bandgap allows it to outcompete traditional silicon in many respects while offering specific advantages over its cheaper rival. Silicon is generally preferred as the go-to semiconductor material in power electronics; however SiC offers several distinct advantages that justify its higher cost in demanding applications like power converters found in terrestrial electric vehicle power converters or space exploration equipment (Mantooth Zetterling and Rusu).

Silicon carbide devices outshone silicon counterparts by operating at higher temperatures, having greater blocking voltage capabilities and offering reduced switching losses. Furthermore, their high frequency capability allowed for faster switching frequencies that ultimately reduced component and system size and weight and improved power density. SiC transistors’ low switching losses allow them to be seamlessly incorporated into existing designs without major redesigns required, speeding development turnaround times while helping cut bills of materials (BOM) costs significantly.

Switching losses are caused by voltage drops and recovery times in MOSFET body diodes when power conversion devices switch on or off, leading to significant energy being wasted. SiC devices offer significantly reduced switching losses and greater efficiency compared to their silicon counterparts for use in new power conversion designs.

N-channel enhancement mode SiC MOSFETs are designed and processed similarly to their silicon counterparts, with similar performance for many power conversion applications. They can easily fit into conventional AC/DC converter topologies while pairing well with SiC diodes to increase reliability while decreasing overall system losses.

UnitedSiC’s approach to performance optimization includes optimizing device structure, parasitics and gate on-off resistance in order to deliver an efficient solution that is compatible with existing design flows. By employing small device snubbers and optimizing gate on-off resistors they have been able to achieve better control of dV/dt, overshoots, and ringing than could otherwise be accomplished simply through increasing gate resistance alone.