What the Future Holds for WBG Devices - Eetasia.com

Article By : Maurizio Di Paolo Emilio

Silicon carbide (SiC) and gallium nitride (GaN) person witnessed expanding occurrence successful the semiconductor instrumentality marketplace successful caller years. GaN is present utilized successful mobile instrumentality chargers and charging systems. Companies similar Apple, Samsung, and Xiaomi person chosen GaN-based chargers that supply precocious powerfulness densities portion maintaining, oregon adjacent decreasing, the value of these components. These chargers utilize powerfulness GaN high-electron–mobility transistor (HEMT) chips offered by companies similar GaN Systems and Navitas Semiconductor.

On the different hand, SiC devices person chiefly been utilized successful the tract of electrical mobility. In 2017, electric-vehicle manufacturers similar Tesla chose to usage SiC-based centrifugal controllers, which boosted the ratio of their systems. This has kickstarted a contention toward processing precocious volumes of SiC devices to conscionable the expanding magnitude of EVs that are being introduced into the market.

Their popularity begs the question: What is truthful peculiar astir these caller semiconductor materials, and wherefore are they being looked astatine arsenic alternatives to silicon?

SiC and GaN vs silicon

As explained by Victor Veliadis in his July 28, 2022, PSMA webinar, “SiC Power Technology Status and Barriers to Overcome,” “SiC and GaN materials person a captious electrical tract that is astir 10× higher than that of silicon, with a bandgap that is 3× higher. In a semiconductor system, the drift furniture is what holds its rated voltage, which makes the thickness and doping levels of this furniture find the voltage capableness of the device.”

For a circumstantial rated voltage, the thickness of the drift furniture is inversely proportional to the captious electrical field. This implies that GaN and SiC devices of a peculiar voltage capableness person drift layers that are 10× thinner than those of silicon devices. These factors thrust plan changes and person large implications successful semiconductor design.

Due to their thinner drift layers, SiC devices are smaller successful size, which decreases their capacitance. These devices tin truthful efficiently power astatine frequencies overmuch higher than what is imaginable with silicon. As a effect of the higher switching frequency, the size of passive components and magnetic devices similar inductors besides decreases. This leads to a important simplification successful the wide size of the system, which increases its powerfulness density. Furthermore, the ample SiC bandgap and precocious thermal conductivity let for precocious somesthesia cognition with simplified cooling management, further decreasing strategy value and volume.

None of this is to accidental that either SiC oregon GaN is superior oregon that silicon is obsolete. The prime of semiconductor worldly to beryllium utilized volition beryllium connected the specifications of the exertion successful which they are deployed. Silicon is inactive a beardown contender successful devices rated from 15 V to 650 V portion besides being overmuch cheaper and much reliable, whereas GaN has been gaining popularity successful low-power applications similar mobile chargers and akin charging systems. As antecedently mentioned, GaN is the lone viable wide-bandgap alternate to silicon successful low-power applications, arsenic SiC cognition is impractical astatine voltages beneath 650 V.

Figure 1: Si, SiC, and GaN (Source: Victor Veliadis)

Power origin correction

GaN enables a powerfulness origin correction (PFC) exertion known arsenic “totem-pole bridgeless PFC topology.” On the different hand, a accepted silicon boost solution would person a diode span wherever 2 of the diodes are perpetually on. This would lend to important losses but is mitigated by GaN owed to its fundamentally zero reverse recovery. 100-V GaN devices are besides being deployed astatine information centers, arsenic server racks are progressively moving toward 48 V. Furthermore, 650-V GaN devices tin besides beryllium deployed and tally for PFC circuitry. SiC is suitable for higher-power applications than what is imaginable utilizing GaN and is disposable successful voltages ranging from 650 V to 3.3 kV, with higher-voltage devices being developed.

Stephen Russell, taxable substance adept for powerfulness devices astatine Tech Insights, said during a institution webinar, “Gallium nitride has genuinely recovered its slayer app successful replacing silicon and USB-C chargers for mobile devices. 2021 [was] a watershed twelvemonth successful marketplace acceptance, and we lone expect this momentum to continue. Gallium nitride’s existent advantage, however, is its switching; it is the lone viable wide-bandgap replacement for silicon astatine voltages little than 600 V.”

All of these devices vie heavy astatine the 650-V capacity, which is important, arsenic these devices are utilized successful the 400-V capableness autobus for EVs.

EVs

EVs are a captious exertion for these recently adopted high-bandgap devices, arsenic the marketplace is expected to expand. This translation is taking spot owing to the accelerated electrification crossed sectors and accrued consciousness astir emissions. They tin beryllium seen successful centrifugal drivers, DC/DC converters, on-board chargers, etc.

SiC is expected to person an borderline successful the EV sector, arsenic much and much manufacturers are moving toward 800-V EV systems, owed to its businesslike high-voltage operational capability. Transitioning to higher-voltage systems enables higher powerfulness transportation portion maintaining the aforesaid existent levels. This allows copper conductors and different components to beryllium smaller, lighter, and little expensive.

Manufacturers similar Porsche, Audi, BYD, and Hyundai are already moving connected 800-V artillery systems, portion Lucid has a 900-V strategy nether development. As Veliadis said, “Moving to 800 V portion keeping the existent the aforesaid doubles the power, with smaller losses. This reduces dense copper cables, bringing lighter value and space-saving advantages.”

Once adopted successfully into the EV space, the request for SiC devices volition further summation manufacturing. This volition yet standard down prices akin to silicon-based devices aft wide production. The alteration successful outgo is an important step, arsenic these devices are much costly than silicon, with SiC worldly costing astir 2× to 3× arsenic overmuch arsenic silicon.

Price and production

Apart from the precocious cost, manufacturing SiC has its ain acceptable of challenges, specified arsenic the beingness of defects and slower fabrication times compared with silicon, and SiC devices are little rugged. This discourages radical from adopting SiC-based systems and is simply a situation to overcome. Due to their high-voltage potential, SiC devices are fantabulous candidates for deployment successful powerfulness applications similar HVDC transmission and renewable vigor systems. For example, successful the lawsuit of PV applications, though the SiC instrumentality outgo is 3× higher than that of silicon, the wide strategy outgo is little owed to the simplification successful the size of the passive elements.

Market projections for the semiconductor industry

Despite the challenges they face, wide-bandgap devices are projected to beryllium wide adopted crossed galore industries and markets. Today, SiC and GaN are the lone wide-bandgap semiconductor materials with commercially disposable powerfulness devices for a wide scope of applications. Depending connected their instrumentality powerfulness ratings, these materials tin find applications successful a assortment of industries.

Figure 2: SiC fab infrastructures (Source: Victor Veliadis)

There are besides projections showing that the SiC marketplace is expected to beryllium worthy $6.5 cardinal by 2027. GaN devices volition predominate the low-power mobile exertion industry, with much devices expected to scope the marketplace with powerfulness densities higher than 20 W/in.³. These devices are expected to bring important ratio improvements and connection idiosyncratic convenience.

Unfortunately, SiC substrate and GaN epitaxy connected silicon substrate accumulation is much analyzable and labor-intensive than that of silicon wafers, and this drives up cost. Moreover, the SiC and GaN marketplace is overmuch smaller, and it is simply a agelong mode from a large-scale standardized part of labor, arsenic the main process technologies are successful the hands of a fewer prime businesses. To flooded specified issues, SiC and GaN indispensable beryllium mass-produced, which volition bring economies-of-scale outgo reductions.

This nonfiction was primitively published on EE Times.

Maurizio Di Paolo Emilio has a Ph.D. successful Physics and is simply a Telecommunications Engineer. He has worked connected assorted planetary projects successful the tract of gravitational waves probe designing a thermal compensation system, x-ray microbeams, and abstraction technologies for communications and centrifugal control. Since 2007, helium has collaborated with respective Italian and English blogs and magazines arsenic a method writer, specializing successful electronics and technology. From 2015 to 2018, helium was the editor-in-chief of Firmware and Elettronica Open Source. Maurizio enjoys penning and telling stories astir Power Electronics, Wide Bandgap Semiconductors, Automotive, IoT, Digital, Energy, and Quantum. Maurizio is presently editor-in-chief of Power Electronics News and EEWeb, and European Correspondent of EE Times. He is the big of PowerUP, a podcast astir powerfulness electronics. He has contributed to a fig of method and technological articles arsenic good arsenic a mates of Springer books connected vigor harvesting and information acquisition and power systems.