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.
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.
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.
Dr. Michael Krieger
Phone: +49 9131 85-28427
Dr. Michael Krieger
Phone: +49 9131 85-28427
Dr. Susanne Langer | idw - Informationsdienst Wissenschaft
Smart windows that self-illuminate on rainy days
29.05.2020 | Pohang University of Science & Technology (POSTECH)
Skoltech scientists get a sneak peek of a key process in battery 'life'
28.05.2020 | Skolkovo Institute of Science and Technology (Skoltech)
In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".
Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...
Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.
researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...
Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.
When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...
Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.
Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...
Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.
A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...
19.05.2020 | Event News
07.04.2020 | Event News
06.04.2020 | Event News
29.05.2020 | Materials Sciences
29.05.2020 | Materials Sciences
29.05.2020 | Power and Electrical Engineering