
Transistor Schematics of the new transistor: the insulator in red and blue, and the semiconductor above (Credit: TU Wien)
An important breakthrough in transistor technology has been achieved at TU Wien: With the help of novel insulators, high-quality transistors can be produced using two-dimensional materials.
For decades, the transistors on our microchips have become smaller, faster and cheaper. Approximately every two years the number of transistors on commercial chips has doubled – this phenomenon became known as “Moore’s Law”. But for several years now, Moore’s law does not hold any more. The miniaturization has reached a natural limit, as completely new problems arise when a length scale of only a few nanometers is approached.
Now, however, the next big miniaturization step could soon become possible – with so-called “two-dimensional (2D) materials” that may consist of only a single atomic layer. With the help of a novel insulator made of calcium fluoride, scientists at TU Wien (Vienna) have created an ultra-thin transistor, which has excellent electrical properties and, in contrast to previous technologies, can be miniaturized to an extremely small size. The new technology has now been presented in the journal “Nature Electronics”.
Ultra-Thin Semiconductors and Insulators
Research on semiconductor materials needed to fabricate transistors has seen significant progress in recent years. Today, ultra-thin semiconductors can be made of 2D materials, consisting of only a few atomic layers. “But this is not enough to build an extremely small transistor,” says Professor Tibor Grasser from the Institute of Microelectronics at TU Wien. “In addition to the ultra-thin semiconductor, we also need an ultra-thin insulator.”
This is due to the fundamental design structure of a transistor: current can flow from one side of the transistor to the other, but only if a voltage is applied in the middle, creating an electric field. The electrode providing this field must be electrically insulated from the semiconductor itself. “There have already been transistor experiments with ultra-thin semiconductors, but until now they were coupled with ordinary insulators,” says Tibor Grasser. “There is not much benefit in reducing the thickness of the semiconductor when it still has to be combined with a thick layer of insulator material. There is no way of miniaturizing such a transistor any further. Also, at very small length scales the insulator surface turned out to disturb the electronic properties of the semiconductor.”
Therefore, Yury Illarionov, a postdoc in Tibor Grasser’s team, tried a novel approach. He used ultra-thin 2D-materials not only for the semiconductor part of the transistor, but also for the insulating part. By selecting ultra-thin insulating materials such as ionic crystals, a transistor with a size of only a few nanometers can be built. The electronic properties are improved because ionic crystals can have a perfectly regular surface, without a single atom protruding from the surface, which could disturb the electric field. “Conventional materials have covalent bonds in the third dimension – atoms that couple to the neighboring materials above and below,” explains Tibor Grasser. “This is not the case in 2D materials and ionic crystals, and so they do not interfere with the electrical properties of the semiconductor.”
The Prototype is a World Champion
To produce the new ultra-thin transistor, calcium fluoride was selected as the insulating material. The calcium fluoride layer was produced at the Ioffe Institute in St. Petersburg, where the first author of the publication, Yury Illarionov, is originally from before joining the team in Vienna. The transistor itself was then manufactured by Prof. Thomas Müller’s team at the Institute of Photonics at TU Wien and analyzed at the Institute for Microelectronics.
The very first prototype already surpassed all expectations: “For years, we have received quite a number of different transistors to investigate their technical properties – but we have never seen anything like our transistor with the calcium fluoride insulator,” says Tibor Grasser. “The prototype with its superior electrical properties outshines all previous models.”
Now the team wants to find out which combinations of insulators and semiconductors work best. It may take a few more years before the technology can be used for commercially available computer chips as the manufacturing processes for the material layers still need to be improved. “In general, however, there is no doubt that transistors made of 2D materials are a highly interesting option for the future,” says Tibor Grasser. “From a scientific point of view, it is clear that the fluorides we have just tested are currently the best solution for the insulator problem. Now, only a few technical questions remain to be answered. ”
This new kind of smaller and faster transistor should enable the computer industry to take the next big step. This way, Moore’s law of exponentially increasing computer power could soon come to life again.
Learn more: Ultrathin Transistors for Faster Computer Chips
The Latest on: Ultra-thin transistor
via Google News
The Latest on: Ultra-thin transistor
- CMOS-compatible ferroelectric NAND flash memory for high-density, low-power, and high-speed three-dimensional memoryon January 14, 2021 at 3:28 am
Current flash memory devices used in massive data storage for mobile devices and servers are based on floating-gate or charge-trap memory transistors using electron tunneling through a tunnel oxide (1 ...
- Efficiency at All Levelson January 11, 2021 at 4:00 pm
Moreover, the absence of channel doping and pocket implants in the fully depleted transistor produce lower noise and higher ... passive and dynamic power consumptions. Thanks to its ultra-thin body ...
- Novel technique helps develop ultra-thin sensor for smart contact lenseson January 7, 2021 at 5:59 am
Researchers have developed a multifunctional ultra-thin sensor using a new manufacturing process – an innovation that could pave the way for the production of smart contact lenses.
- Manufacturing process of ultra-thin sensor for smart contact lenseson January 6, 2021 at 2:41 pm
Professor Sheng Zhang, co-author from Zhejiang University, said: "This multifunctional contact lens with field-effect transistors ... Manufacturing process of ultra-thin sensor for smart contact ...
- Ultra-thin sensors in ‘smart’ contact lenses could monitor user healthon January 6, 2021 at 11:56 am
“Our ultra-thin sensor layer is different from the conventional smart ... “This multifunctional contact lens with field-effect transistors can provide diversified signals from eyes, which could be ...
- Surrey unveils breakthrough manufacturing process of ultra-thin sensor for smart contact lenseson January 6, 2021 at 8:22 am
Dr Shiqi Guo, the first author of this study and current postdoctoral research fellow at Harvard University, said: "Our ultra-thin sensor ... lens with field-effect transistors can provide ...
- A breakthrough manufacturing process of ultra-thin sensor for smart contact lenseson January 6, 2021 at 7:51 am
Professor Sheng Zhang, co-author from Zhejiang University, said:"This multifunctional contact lens with field-effect transistors is able to provide diversified signals from eyes, which could be ...
- Automotive Electronicson January 5, 2021 at 4:00 pm
French PSU maker BrightLoop Converters has built its latest automotive dc-dc converter around GaN transistors from EPC. “By switching from silicon transistors to gallium nitride,” said EPC.
- Cool RF Transistors Pack A Mean Punchon January 3, 2021 at 4:01 pm
In contrast, Agere's transistors may eventually give way to ... it eliminates the defects that have traditionally occurred when making ultra-thin silicon wafers. The resulting chips are not ...
- RF Power Transistor Family Claimed As Industry’s Cooleston November 22, 2020 at 4:00 pm
such as elimination of defects in chips when making ultra-thin silicon wafers and through use of high-density, low-resistance electrical connections. The RF power transistor family currently ...
via Bing News