Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Saving energy by taking a close look inside transistors

10.01.2019

New method finds defects in power transistors more accurately, quickly and simply

Transistors are needed wherever current flows, and they are an indispensable component of virtually all electronic switches. In the field of power electronics, transistors are used to switch large currents.


Physicist Martin Hauck fits a silicon carbide transistor into the measuring apparatus: researchers at FAU have discovered a method for finding defects at the interfaces of switches

FAU/Michael Krieger, Martin Hauck

However, one side-effect is that the components heat up and energy is lost as a result. One way of combating this and potentially making considerable savings is to use energy-efficient transistors. Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have developed a simple yet accurate method for finding defects in the latest generation of silicon carbide transistors.

This will speed up the process of developing more energy-efficient transistors in future. They have now published their findings in the renowned journal Communications Physics.*

Boosting the efficiency of power electronic devices is one way to save energy in our highly technological world. It is these components which ensure that power from photovoltaic or wind power stations are fed into the grid, the traction units of trains are supplied with current from the overhead line, and energy is transferred from batteries to the engine in electric and hybrid vehicles.

At the same time, however, these components should ideally use as little electricity as possible. If not, heat is generated unnecessarily, additional complex cooling systems are needed and energy is wasted as a result.

This is where components made of silicon, the standard semiconductor material, reach their limits on the basis of their intrinsic material properties. There is, however, a much more suitable alternative: silicon carbide, or SiC for short, a compound made of silicon and carbon.

Its properties speak for themselves: it withstands high voltages, works even at high temperatures, is chemically robust and is able to work at high switching frequencies, which enables even better energy efficiency. SiC components have been used very successfully for several years now.

Investigating charge trapping

Power electronic switches made of silicon carbide, known as field-effect transistors or MOSFETs for short, work on the basis of the interface between the SiC and a very thin layer of silicon oxide which is deposited or grown on it.

It is this interface, however, which poses a significant challenge for researchers: during fabrication, undesired defects are created at the interface which trap charge carriers and reduce the electrical current in the device. Research into these defects is therefore of paramount importance if we are to make full use of the potential offered by the material.

Pattern discovered

Conventional measurement techniques, which have usually been developed with silicon MOSFET devices in mind, simply ignore the existence of such defects. Whilst there are other measurement techniques available, they are more complex and time-consuming, and are either unsuitable for use on a large scale or are simply not suitable for being used on finished components at all. This is the reason why researchers at the Chair of Applied Physics at FAU decided to focus on finding new, improved methods for investigating interface defects – and they were successful.

They noticed that the interface defects always follow the same pattern. ‘We translated this pattern into a mathematical formula,’ explains doctoral candidate Martin Hauck. ‘Using the formula gives us a clever way of taking interface defects into account in our calculations. This doesn’t only give us very precise values for typical device parameters like electron mobility or threshold voltage, it also lets us determine the distribution and density of interface defects almost on the side.

In experiments conducted using transistors specially designed for the purpose by the researchers’ industrial partners Infineon Technologies Austria AG and its subsidiary Kompetenzzentrum für Automobil- & Industrie-Elektronik GmbH, the extremely simple method also proved to be highly accurate.

Taking a close look at the inner core of the field-effect transistors allows now for improved and shorter innovation cycles. Using this method, processes aimed at reducing defects can be evaluated accurately, quickly and simply, and work at developing new, more energy-saving power electronics can be accelerated accordingly.

*doi: https://doi.org/10.1038/s42005-018-0102-8

Further information:
Dr. Michael Krieger
Phone: +49 9131 85-28427
michael.krieger@fau.de

Wissenschaftliche Ansprechpartner:

Dr. Michael Krieger
Phone: +49 9131 85-28427
michael.krieger@fau.de

Originalpublikation:

https://doi.org/10.1038/s42005-018-0102-8

Dr. Susanne Langer | idw - Informationsdienst Wissenschaft
Further information:
http://www.fau.de/

More articles from Power and Electrical Engineering:

nachricht Researchers measure near-perfect performance in low-cost semiconductors
18.03.2019 | Stanford University

nachricht Robot arms with the flexibility of an elephant’s trunk
18.03.2019 | Universität des Saarlandes

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: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>