Tag Archive for: Wide band gap

GE to supply SiC dies for Danfoss power modules

Danfoss Silicon Power and General Electric announced they entered in an agreement this week. Danfoss is establishing a new production site for power modules. This was the opportunity for them to start the production of full SiC based power modules.

The collaboration between Danfoss Silicon Power and General Electric comes as part of the New York Power Electronics Manufacturing Consortium (NY-PEMC). The NY-PEMC is a private-public collaboration with an investment of USD 20 billions established in 2014. By early 2018, Danfoss will have a running production site for Silicon Carbide power modules in Utica, NY. GE will provide SiC MOSFET and Diodes from its own technology and production sites.

New York State will own the buildings and finance start up costs, as an effort to promote innovation. Danfoss Silicon Power will rent them to   the state of New York.

Video of Claus Petersen talking about this partnership

“Danfoss Silicon Power is gaining a unique position as the only independent SiC module manufacturer in the US and GE has been a customer from day one. Similarly, it has opened the door to the US market, where demand for the power modules manufactured by Danfoss Silicon Power is expected to grow explosively,”

says Claus A. Petersen, General Manager and Vice President of Danfoss Silicon Power.

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From March to May: Wrap-up of APEC and PCIM conferences

March to May is the most active period of the year for Power electronics. With the main events that are APEC and PCIM happening two months one from the other, there is a lot to do, a lot to plan and announce too. You might have been buried under tons of work and projects lately (Well, we were!). Don’t worry, PointThePower.com is here to summarize and analyze what happened, and it’s a lot!

Wide band gap field has been very active, and some other trends we announced (car maker entering the smart-grid market or the integration of intelligence in power stacks) have been a bit more confirmed.

Let’s see that in detail.

What’s new about Silicon Carbide

« Silicon Carbide is coming. » We know you have been hearing that for the last decade. So let’s pass the analysis and just go straight to the proofs:

We always said that SiC MOSFET would give its best at higher voltages. Hitachi and Mitsubishi Electric showcased their 1.7kV and 3.3kV full Silicon Carbide MOSFET. They are already filed testing these power modules on their trains in Japan. You could ride a (partially) Silicon Carbide powered trains. That is where SiC belongs, and it’s becoming real, at last.

Infineon has announced their Silicon Carbide MOSFET. It’s coming late, but it seems they did a good work. According to the presentation they gave at PCIM, they wanted to build a device that meets their requirements. They did not want to enter into a race of announcements. So the device is a Trench MOSFET – available at 1200V in samples from now, and in full production in 2017. You can basically replace chip-to-chip an IGBT with this MOSFET. It accepts the same inputs from the driver. But of course, you can get better performances using a specific power device driver. It starts sampling now but will be fully available by 2017.

Rohm also showcased a Trench SiC MOSFET, but for them it’s the third generation. The main improvement is about surge robustness which is now time higher. They recalled that they have a fully integrated supply-chain. The new devices are available at higher current (the technology was presented last year.). They now propose power modules up to 1200V/300A.

Littelfuse is investing more and more in partnership with Monolith Semiconductors to propose a full line of Silicon carbide devices and modules.

On the higher voltage side, Wolfspeed (formerly Cree power branch), Hitachi and Mitsubishi Electric make their way to higher voltages. The devices are not publicly available but tests are currently on-going. The main target for 1.7kV and 3.3kV Silicon Carbide MOSFETs are Rail traction inverters, Grid or Wind turbines.

What to expect for SiC in the next months:

We will see higher voltage devices becoming available. With wafers becoming larger (production is moving to 6 in.), we also need to expect bigger volumes of production and a reduction of production costs, thus production price. High voltage devices (1.7kV and more) will be more and more visible. It does not mean that you will be able to use them yet, but you will see more and more papers, presentations, and maybe a few public announcements about their use. R&D and design engineer will be able to put their hands on some of them, which is still very difficult today.

What’s new in GaN:

Shindengen developed and showed a Power module with GaN devices from Transphorm. Most power module maker’s start to work on the developments of their product line. They just need to « bet on the right horse ».

ViSIC is proposing sampling of its 600V GaN devices. They claim to have the best figure of merit of the market to date. Mass production will start in 2016 too. They partnered with TSMC toward this objective.

ExaGaN found a local partner to test and qualify their GaN devices.

GaN IC: a necessity?

Navitas semiconductor came out of « stealth mode ». They presented their solution which is a GaN IC. You have the GaN power device and the driver on the same die. It’s not a mixed packaged (With Silicon and Gallium Nitride, but a single die IC). It’s a 650V device processed on 6 in. wafers and samples will be available by the beginning of 2017.

Texas Instruments also released their GaN IC at 600V/12A. Even though they do not attend PCIM yet. They did not disclose much information about the device. It seems to be similar to the product develop day Navitas semiconductor having the driver integrated and thus making life easier for designers facilitate device adoption. Infineon has the same strategy with their SiC MOSFET (which is, in theory, compatible with IGBT gate drives).

What to expect for GaN in the next months

We will probably see more and more announcement, and more and more products. Some power module maker will announce the availability of their GaN based power modules. Some GaN players will have to show what they have to stay in the race (Cambridge Electronics Inc. must be working on their manufacturing process to transfer it to mass production and Powdec must be preparing their device).

Other players will make all efforts to push their devices to the market.

We have a complete analysis of the situation available in our market report « Applications and Markets for GaN in Power Electronics .» Ask us for more info.

What is left for Silicon:

Toshiba announced the fifth version of the Super Junction MOSFET. It’s based on their « Deep trench » process using deep reactive ion etching to dig a hole and build the super junction structure in it. Super Junction MOSFET is the perfect competitor to GaN today, and high-end products that use SJ MOSFET are the most likely to move to Gallium Nitride HeMT tomorrow.

Infineon showed during PCIM, a 12 in. wafer with IGBTs processed on it. They will reduce again the cost of production of IGBTs by processing them on larger wafers. It makes the target harder to reach for competition. They also showed a double sided cooled modules for hybrid and electric cars. It’s very similar to what was used in 2008 Lexus LS600h by Toyota (and developed by Denso). The module has a DBC on top and another on the bottom side.

You can also note the partnership between Nissan and Eaton, to reuse EV batteries in home storage systems. This confirms our forecast of a main supply-chain trend: similarly to Alstom, Siemens and GE in high power, electric car makers will also become part of whole ‘consumer-level’ energy complex scheme that will make Smart-grid real.

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Ascatron raises 4 M€ to launch its own SiC devices product line

Ascatron develops power semiconductors based on Silicon Carbide (SiC) that radically reduce losses in electrical transformers. Ascatron focuses on high voltage applications where the energy savings will be very large by using SiC.

Ascatron SiC Silicon Carbide diode package 3DSiC high temperature

1200V SiC power diode for high temperature operation at 250°C

They have now completed the A-round financing intended for the final development of its first own SiC semiconductor products. The total of 4 M€ is shared between 3 M€ in equity capital, and
1 M€ in an innovation grant.

“We have started to implement our advanced material technology in a production equipment for SiC epitaxy”, says Adolf Schöner, CTO of Ascatron.

“The next step is to optimize our device design and outsource the remaining manufacturing of the chip to a foundry with capacity for volume production”.

The A-round investors are from Italy and China, including the four venture capital investors Quadrivio, Como Venture, Rise Leader Investment and InteBridge Technology, together with the equipment producer LPE. The grant comes from the European Institute of Innovation and Technology (EIT) through KIC InnoEnergy. KIC supports innovation projects in the field of sustainable energy.

“Our investors have a good mix of understanding both the advanced material technology needed for high performance SiC power devices, and how to address volume markets for semiconductors”

says Christian Vieider, CEO of Ascatron. “40% of the market for power electronic components is in China, and there is a lot of interest in SiC for energy saving”.

About Ascatron

Ascatron develops next generation Silicon Carbide (SiC) power semiconductors radically reducing electrical conversion losses. Target applications are process industry, data center, traction, wind power and grid transformers. With the 3DSiC® technology Ascatron makes doped device structures based on epitaxy, enabling device performance with very low losses and capacity to handle very high voltage. Ascatron started the operation in 2011 as a spin-out from the Swedish R&D institute Acreo, and has 10 employees in Sweden. www.ascatron.com

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Hirex engineering to test and qualify ExagaN G-FET GaN transistors

Exagan, a start-up manufacturing gallium nitride (GaN) semiconductor technology for power electronics has begun a strategic partnership to develop and commercialize GaN-on-silicon products withHIREX Engineering, a company of Alter Technology Group (TÜV NORD GROUP’s Aerospace and Electronics Business Unit). The partnership’s goal is to establish the reliability and quality of GaN-on-silicon power devices.
Exagan will work closely with HIREX Engineering, a leader in reliability testing and qualification of ICs and discrete semiconductors for aerospace and industrial high-reliability applications. HIREX Engineering is located near Toulouse, France. Together, the companies will test and qualify Exagan’s G-FET™ products, which are fabricated with standard 200-mm silicon processing and proprietary G-Stack™ technology. G-FETs are used in making smaller, more efficient power converters that have a broad range of applications (plug-in hybrid and full-electric vehicles, solar energy, industrial applications, or charging of all mobile electronic devices).

“This dynamic partnership will help to propel GaN market development by pioneering test methodologies and measurement processes that make it easier for makers of electrical converters to implement GaN in improving their products,” said Frédéric Dupont, president and CEO of Exagan.

“This timing is perfect to combine Exagan’s strengths with those of the top European specialist in high-reliability testing. GaN technology has matured to deliver the high performance of SiC (silicon carbide) devices at silicon ICs’ price and quality levels, and our key markets are ready for this next-generation solution.”

“Through its participation, HIREX Engineering will expand its expertise and business portfolio to include advanced power GaN technology and the end products it enables. We hope to establish robust and easy-to-reference product parameters for GaN that will allow fast integration in electrical converters,” said Luis Gomez, Alter Technology Group CEO.

“We are confident that GaN’s bulletproof reliability will present remarkable advantages in the fast-growing power electronics market,” said Dr. Guido Rettig, TÜV NORD GROUP CEO.

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X-FAB offers high-volume 6-inch SiC foundry production

X-FAB Silicon Foundries of Erfurt, Germany – a mixed-signal IC, sensor and micro-electro-mechanical systems (MEMS) foundry – has entered wide-bandgap semiconductor production by announcing the availability of silicon carbide (SiC) foundry from its wafer fabrication plant in Lubbock, Texas.

The firm says that, due to major internal investments in the conversion of capital equipment (as well as the support provided by the PowerAmerica Institute at North Carolina State University), X-FAB Texas has heavily upgraded its manufacturing resources in order to be ‘SiC-ready’. Among the tools now added are a high-temperature anneal furnace, backgrind equipment for thinning SiC wafers, backside metal sputter and backside laser anneal tools. A high-temperature implanter is scheduled for installation later this year. X-FAB can hence now fully leverage the economies of scale that are already available in its established 30,000 wafer per month silicon line, presenting the market with the means to produce large volumes of SiC devices on 6-inch wafers.

X- FAB says that, as well as its 6-inch wafer capabilities, other key differentiators include higher yields and accelerated ramp-up to full-scale production, plus decades of experience in manufacturing semiconductor devices that adhere to the most stringent quality standards (such as those for automotive applications). The firm will not only supply fabless semiconductor vendors but also act as a second source for integrated device manufacturers (IDMs) with their own SiC production capabilities.

“Current SiC offerings are either IDMs creating their own products or relatively small foundry operations using 4-inch production facilities,” says Andy Wilson, X-FAB’s director of strategic business development. “X-FAB is bringing something different to the market, with a SiC capacity of 5000 wafers/month ready to utilize and potential to raise this further,” he adds. “We can thus offer a scalable, high-quality, secure platform that will enable customers to cost-effectively obtain discrete devices on SiC substrates and also safely apply vital differentiation.”

In 2015, SiC diode and MOSFET supplier Monolith Semiconductor Inc of Ithaca, NY, USA relocated its headquarters from Ithaca, New York, to Round Rock, Texas, following a strategic partnership announced in 2014 for the manufacture of its SiC switches in X-FAB Texas’ high-volume 150mm silicon production line.

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Pi Innovo and GaN Systems to promote GaN in automotive

A collaboration between Pi Innovo’s electronics design and development expertise and GaN Systems’ gallium nitride (GaN) semiconductors, offers automakers a pathway to the electrification of auxiliary systems for multi-voltage conventional, hybrid-electric, and pure electric vehicles.

Based on GaN Systems’  technology, gallium nitride devices use GaN-on-silicon base wafers. The company manufactures a range of gallium nitride power transistors for automotive, consumer, datacenter, industrial and solar/wind/smart grid applications.

Pi Innovo has designed and implemented custom motor control electronics to take advantage of the benefits of GaN Systems semiconductors in applications with a range of input voltages from 12V to 300V. This controller design provides a functional starting-point for the development of 48V and above, high-speed motor-driven vehicle systems, and adds to a growing portion of Pi Innovo’s business providing custom electronics solutions across multiple markets.

PI Innovo GaN Systems motor drive for electric vehicle

Following the success of this GaN-based multi-voltage motor controller development project, Pi Innovo is now offering design and development services in support of customers looking to adopt this technology for a wide range of electronics design applications in automotive and adjacent markets. The company is positioned to support customers wanting to develop prototype evaluations to quantify the benefits of GaN technology. Pi Innovo can also provide customized cost effective high volume designs for customers looking to go into production.

“Pi Innovo’s hardware, software and applications engineers worked closely with the GaN Systems team to understand their semiconductor design requirements and to ensure the final controller design maximizes the reduction in size, weight and power consumption benefits that gallium nitride semiconductors provide,”

said Dr. Walter Lucking, CEO of Pi Innovo.

“Working with GaN Systems on this project has been a great experience for our team and we’re looking forward to continuing our close partnership to support our customers on many future designs.”

“Having a technology development partner like Pi Innovo that really understands the intricacies of control electronics design for vehicle applications, is invaluable in supporting the continued adoption of GaN in the electrification of vehicle systems,” said Jim Witham, GaN Systems’ CEO.

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LittelFuse invests in SiC through Monolith Semiconductor

As part of the company’s strategy to move more significantly into power semiconductors for industrial and automotive markets, Littelfuse has made an investment in Monolith Semiconductor, Inc., a start-up company developing silicon carbide technology. Silicon carbide is a rapidly emerging semiconductor material that enables power devices to operate at higher switching frequencies and temperatures versus conventional silicon. This allows inverters and other energy conversion systems to be built with significantly improved power density, energy efficiency and cost.

“Investing in and partnering with Monolith’s experienced team of silicon carbide and power semiconductor experts allows us to quickly evolve our portfolio with strategically relevant and innovative technology,”

said Ian Highley, Littelfuse Senior VP and GM, Semiconductor Products, and CTO.

“Silicon carbide power technology is among the most promising advancements in the semiconductor market today. It will be an important tool in helping us solve complex problems for our customers.”

“Forming this strategic partnership with Littelfuse accelerates development and helps bring silicon carbide technology to the market,” said Sujit Banerjee, PhD, CEO of Monolith Semiconductor. “Littelfuse is an ideal partner for us. We are excited to dramatically increase our customer reach, gain access to global channels, and benefit from their sales and marketing depth and expertise.”

Initially this is not a material investment for Littelfuse; however, the company has committed to add to its investment once Monolith has achieved certain milestones. This investment is not expected to have any material financial impact on Littelfuse in 2015 or 2016.

About Littelfuse
Founded in 1927, Littelfuse is the world leader in protection with growing global platforms in power controls and sensing. The company serves global customers in the electronics, automotive and industrial markets with technologies including fuses, semiconductors, polymers, ceramics, relays and sensors. Littelfuse has over 8,000 employees in more than 35 locations throughout the Americas, Europe and Asia. For more information, please visit the Littelfuse website: Littelfuse.com.

About Monolith Semiconductor
Monolith Semiconductor Inc., a Round Rock, Texas-based startup company, is focused on improving the affordability and reliability of SiC power devices by utilizing advanced manufacturing techniques and high-performance processes and designs. For more information, please visit the Monolith Semiconductor website: monolithsemi.com.

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GaN Systems multiply by 10 its production capacity

GaN Systems, the manufacturer of gallium nitride power transistors, announces that its foundry, Taiwan Semiconductor Manufacturing Corporation (TMSC), has expanded the volume production of products based on GaN System’s Island Technology® by 10X in response to demand from consumer and enterprise customers.

GaN Systems has the industry’s broadest and most comprehensive portfolio of GaN power transistors with both 100V and 650V GaN FETs shipping in volume.

The unique combination of TSMC’s gallium nitride process and GaN Systems’ proprietary Island Technology design is further enhanced by GaNPX™ packaging, which delivers high current handling, extremely low inductance and exceptional thermal performance. GaN Systems’ power switching transistors continue to lead the gallium nitride market, providing best-in-class 100V and 650V devices and driving product innovation ranging from thinner TVs to extended range electric vehicles. Sajiv Dalal, VP Business Management at TSMC, comments,

“We are delighted to confirm that our collaboration with GaN Systems has brought the promise of gallium nitride from concept through reliability testing and on to volume production.” Adds Girvan Patterson, GaN Systems’ President,

“GaN has emerged as the power semiconductor solution of choice. Smart mobile devices, slim TVs, games consoles, automotive systems and other mass volume items have been designed with GaN transistors as the enabling power technology, so it is imperative that devices are available in correspondingly large quantities. That is why, after three years of working together, we are so excited to formally announce our collaboration with TSMC.”

Using Island Technology with TSMC’s GaN-on-Silicon manufacturing techniques enabled GaN Systems to deliver the most usable, high performance, normally-off transistor to the market in mid-2014. This has allowed global power system manufacturers in the energy storage, enterprise and consumer markets to design, develop, test and bring to market more powerful, lighter and far smaller new products in their quest to attain competitive edge. To meet customers’ increasing demand for high GaN volumes in 2016, TSMC’s commitment to volume production flow comes at the perfect time.

Check our GaN Market report to know more about GaN Systems and their potential

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Rohm expands its full SiC power module lineup

Rohm has recently announced the development of a 1200V/300A full SiC power module designed for inverters and converters in solar power conditioners and industrial equipment.

The high 300A rated current makes the BSM300D12P2E001 suitable for high power applications such as large-capacity power supplies for industrial equipment, while 77% lower switching loss vs. conventional IGBT modules enables high-frequency operation, contributing to smaller cooling countermeasures and peripheral components.

In March 2012, ROHM began mass production of the world’s first full SiC power module with an integrated power semiconductor element composed entirely of silicon carbide. In addition, its 120A and 180A/1200V products continue to see increased adoption in the industrial and power sectors. And although further increases in current are possible due to energy-saving effects, in order to maximize the high-speed switching capability of SiC products, an entirely new package design is needed that can minimize the effects of surge voltage during switching, which can become particularly problematic at higher currents.

In response, the BSM300D12P2E001 features an optimized chip layout and module construction that significantly reduces internal inductance, suppressing surge voltage while enabling support for higher current operation up to 300A. And going forward, ROHM will continue to strengthen its lineup by developing products compatible with larger currents by incorporating SiC devices utilizing high voltage modules and trench configurations.

Key Features
1. Reduced switching loss through higher frequency operation
Replacing IGBT modules is expected to reduce switching loss by up to 77%, enabling smaller cooling systems to be used. And higher frequency switching will make it possible to decrease the size of peripheral components such as the coil and capacitors, improving efficiency while contributing to greater end-product miniaturization

2. Lower inductance improves current-handling capability
Increasing the rated current for power modules involves reducing the internal inductance to counter the higher surge voltages generated during switching. The BSM300D12P2E001 features an all-SiC construction and optimized circuit layout that cuts internal inductance by half, making it possible to increase the rated current to 300A.

Device Characteristics

  • Full SiC module integrates an SiC SBD and SiC-MOSFET into a single package
  • Equivalent package size as standard IGBT modules
  • Built-in thermistor
  • Tjmax=175 degrees C
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Wolfspeed announce 1700V Silicon Carbide MOSFET

Wolfspeed, the new spin-off from Cree, that makes silicon carbide (SiC) and gallium nitride (GaN) wide-bandgap semiconductor devices, has launched what it claims is the industry’s first 1700V SiC MOSFET offered in an optimized surface-mount (SMD) package. The higher blocking voltage enables design engineers to replace lower-rated silicon MOSFETs with the new SiC MOSFETs, delivering higher efficiency, simplified driver circuitry, and lower thermal dissipation, and resulting in lower total system costs, says the firm.

The new SMD package, specifically designed for high-voltage MOSFETs, has a small footprint with a wide creepage distance (7mm between drain and source). This is made possible by the small die size and high blocking capability of Wolfspeed’s SiC planar MOS technology. The new package also includes a separate driver source connection, which reduces gate ringing and provides clean gate signals.

“Our new 1700V SiC MOSFET provides power electronics engineers with significant design advantages, particularly in flyback topologies,”

claims Edgar Ayerbe, marketing manager for power MOSFETs. “Due to the lower switching losses of silicon carbide, the devices operate at much lower junction temperatures. This enables customers to directly mount the devices onto the PCB with no additional heat-sinks, which greatly reduces the manufacturing costs and improves the reliability of the systems,” he adds.

“The result is a smaller, lighter power supply with a lower system cost than is possible using silicon devices.”

Application of the new 1700V SiC MOSFET is anticipated in auxiliary power supplies within high-power inverters — such as solar power inverters, motor drives, uninterruptible power system (UPS) equipment, wind-energy converters, and traction power systems — which typically buck down DC voltages to operate system logic, protection circuitry, displays, network interface, and cooling fans. They can also be used in the power supplies of three-phase e-meters, or in any converter application that requires high blocking voltages and low capacitance.

Designated the C2M1000170J, the new 1700V SiC MOSFET features an avalanche rating greater than 1800V, and an RDS(on) on-resistance of 1Ω. These characteristics ensure reliable performance in flyback converter circuits, including those in noisy electrical environments such as those found in high-power inverters, says Wolfspeed. By enabling the design of single-switch flyback topologies from input voltages spanning 200V to 1000V, the 1700V SiC MOSFET simplifies the complex drive and snubber circuit elements required for silicon devices, the firm adds.

The C2M1000170J is fully qualified and available for sampling now.

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Ascatron and LPE cooperate on 150 mm SiC epitaxy for power electronics

Ascatron AB, supplier of silicon carbide (SiC) epitaxy material, and LPE SpA, a pioneer in epitaxy reactors for power electronics, have entered into a cooperation agreement to develop high performance SiC epitaxial material for volume production on 150 mm substrates. The first results demonstrating outstanding uniformity will be presented at the ICSCRM2015 conference in Catania.

Ascatron has installed a new SiC epitaxy reactor supplied by LPE in its production fab in Kista-Stockholm. The  reactor system with 150 mm wafer capability has the model name PE106. It is a new development from LPE and has recently been introduced on the market. Industry shortest cycle time and smallest footprint makes it an optimal choice for production of Ascatron’s high quality epitaxial material for high voltage power devices.

“The new production equipment from LPE is key to scale-up Ascatron advanced epitaxy processes to state-of-the-art 150 mm SiC wafers”

,says Christian Vieider, CEO of Ascatron. “We are now ready to provide our customers with n-type doped epi wafers with thicknesses from 0.1 µm up to 100 µm”.

“The new PE1O6 will further enhance Ascatron unique epitaxy based SiC technology, which is set to gain worldwide acceptance among device makers because of its superior features”, according to Franco Preti, CEO of LPE. “The cooperation with Ascatron enables LPE to strengthen our position on the market even further”.

“The single wafer concept of the LPE reactor is ideal to optimize growth parameters for a wide range of processes”, says Adolf Schöner, CTO of Ascatron.

“We are now able to establish our unique growth processes for embedded pn junctions and 3D structures on this 150 mm wafer platform, which is a crucial step towards cost effective production of next generation SiC power devices”.

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Panasonic claims 7.6kA/cm² for a GaN diode

Panasonic Corporation today announced that it developed gallium nitride (GaN) diodes that can not only operate at a high current that is four times greater than that tolerated by conventional silicon carbide (SiC) diodes*1, but also operate at low voltages by virtue of their low turn-on voltage. Production of the new diodes was made possible via a newly developed hybrid structure composed of separately embedded structure comprised of a low-voltage unit and a high-current-capable unit, in preparation for high voltage conditions.

Conventional silicon (Si) diodes are limited with regard to reducing switching losses. On the other hand, diodes based on SiC, a compound that is considered as a promising next-generation power semiconductor, as well as GaN, require an increased chip area to achieve high-current operations, thus posing limitations on the reduction of switching losses and size owing to increased operating frequencies.

GaN gallium nitride diode picture from panasonic

The newly produced GaN diodes have achieved simultaneous high-current operations and low threshold voltage, and thus can handle high currents even with a small chip area. The capacitance of the chip can therefore be reduced to achieve lower switching losses, allowing the device to operate at higher frequencies. As a result, use of GaN diodes in the voltage conversion circuits or inverter circuits of automotive or industrial equipment that requires high power can reduce system size due to high frequency operation.

This newly developed product has the following advantages.

・High-current operation: 7.6 kA/cm2 (approximately 4 times*1)
・Lower turn-on voltage: 0.8 V
・Low on-resistance (RonA): 1.3 mΩcm2 (approximately 50% reduction*1)

The diodes were created based on the following technologies.

Hybrid structure of GaN diodes with a trenched p-GaN layer:

We proposed a hybrid GaN diode with a p-type layer in which trenches are formed, and developed a processing technology that can remove a p-type layer on an n-type layer in a selective manner to achieve not only high-current operations and a low turn-on voltage but also a breakdown voltage of 1.6 kV.

Fabrication of Diodes on a low-resistance GaN substrate:

For this development, we used conductive GaN substrates with a low resistance, which have been commercially used in LEDs and semiconductor lasers and are expected to be adopted in power devices in the future, and established the technologies for the epitaxial growth and processing on a GaN substrate before forming diodes. A structure in which currents flow in the vertical direction enables a smaller chip area and lower resistance.

This work was partially supported by the Ministry of the Environment, Government of Japan.

The results of this development were presented at the 2015 International Conference on Solid State Devices and Materials , Sapporo, Japan (September, 2015).

(*1 Compared to an SiC diode with a rated voltage of 1,200 V)

 

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