Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

IMEC and AIXTRON set important step towards low-cost GaN power devices

03.06.2008
IMEC, an independent European research center in the field of nanoelectronics, and AIXTRON, a metal-organic chemical-vapor deposition (MOCVD) equipment supplier, have demonstrated the growth of high-quality and uniform AlGaN/GaN heterostructures on 200mm silicon wafers. This demonstration is a milestone towards fabricating low-cost GaN power devices for high-efficiency/high-power systems beyond the silicon limits.

IMEC and AIXTRON deposited, for the first time ever, crack-free AlGaN/GaN structures onto 200mm Si(111) wafers. The layers show good crystalline quality as measured by high-resolution x-ray diffraction (HR-XRD). Excellent morphology and uniformity were obtained as well. The high-quality AlGaN and GaN layers were grown in AIXTRON’s application laboratory on the 300mm CRIUS metal-organic chemical-vapor-phase epitaxy (MOVPE) reactor.

“The demonstration of GaN growth on 200mm Si wafers is an important step towards processing GaN devices on large Si wafers”, said Marianne Germain, Program Manager of IMEC’s Efficient Power program. “There is a strong demand for GaN-based solid-state switching devices in the field of power conversion. However, bringing GaN devices to a level acceptable for most applications requires a drastic reduction in the cost of this technology. And that is only possible by processing on large-diameter Si wafers. 150mm, and then 200mm are the minimum wafer sizes we need to fully leverage today’s silicon processing capabilities.” The bow of the resulting wafers is still quite large, in the range of 100µm; but IMEC believes that an optimized buffer can reduce this bow drastically, enabling further processing. Marianne Germain: “We aim to further develop the growth process and to qualify the wafers to be compatible with Si-CMOS process.”

Gallium nitride (GaN) has outstanding capabilities for power, low-noise, high-frequency, high-temperature operations, even in harsh environment (radiation); it considerably extends the application field of solid-state devices. Due to the lack of commercially available GaN substrates, GaN heterostructures are nowadays grown mainly on sapphire and silicon carbide (SiC). Si is a very attractive alternative, being much cheaper than sapphire and SiC. Other benefits include the acceptable thermal conductivity of Si (half of that of SiC) and its availability in large quantities and large wafer sizes. But until now, Si wafers with (111) surface orientation were only available with a diameter up to 150mm. The 200mm wafers were custom-made by MEMC Electronic Materials, Inc. using the Czochralski growth (CZ) method. CZ wafers are ideally suited for switching applications with large breakdown voltages. For such devices, the performance is independent of the resistivity of the Si substrate.

Process details

For the AlGaN/GaN heterostructures, a standard layer stack, that had already been successfully demonstrated on 100 and 150mm Si(111) substrates, was used.

First an AlN layer was deposited onto the Si substrate, followed by an AlGaN buffer which provides compressive stress in the 1 micron thick GaN top layer. The stack was finished with a 20nm thin AlGaN (26% Al) layer and capped with a 2nm GaN layer. From in-situ measurements, researchers from IMEC were able to extract the thickness uniformity of the different layers which show a standard deviation well below 1% over the full 200mm wafers (5mm EE).

Katrien Marent | alfa
Further information:
http://www.imec.be
http://www.aixtron.com

More articles from Power and Electrical Engineering:

nachricht Silicon solar cell of ISFH yields 25% efficiency with passivating POLO contacts
08.12.2016 | Institut für Solarenergieforschung GmbH

nachricht Robot on demand: Mobile machining of aircraft components with high precision
06.12.2016 | Fraunhofer IFAM

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>