Just a few days back, researchers designed nanowires to enhance fuel cell efficiency and here is another investigation which adds to the benefits of this technology. Investigators from the Lund University in Sweden and the University of New South Wales have created a nanowire transistor that features a concentric metal ‘wrap-gate’ sitting horizontally on a silicon substrate. This unique nanowire transistor can supposedly help fabricate a number of vital devices in the near future.
Designed with utter simplicity, this nanowire transistor comes with an ability to tune the length of the wrap-gate via a single wet-etch step. Even the higher densities of transistors have been packed into a microchip to decrease overlap between the semiconductor channel through which the current flows and the metal gate makes it harder to switch the current on and off. This seemingly led to the development of the ‘Fin Field-Effect Transistor’, or FinFET. In this FinFET, the silicon either side of the channel is possibly etched away to produce a raised mesa structure.
So the gate to fold down around the sides of the channel attains a better control and improves the switching without increasing the chip space needed by the device. Getting metal underneath the channel without compromising the device appears as a formidable task using conventional ‘top-down’ silicon microfabrication techniques. These tiny semiconductor needles, around 50 nm in diameter are up to several microns in length. They are apparently grown by chemical vapour deposition and stand vertically on a semiconductor substrate.
Hence, Associate Professor Adam Micolich, an ARC Future Fellow in the Nanoelectronics Group in the UNSW School of Physics and colleagues were able to deposit an insulator and gate metal around the nanowire’s entire outer surface. These coated nanowires can be probably made into fully-functioning transistors in the vertical orientation. However, this may pose as an interesting challenge for nanotechnologists. During the research, experts demonstrated the first such horizontal wrap-gate nanowire transistors. They also highlighted that they can be made through a significantly simple process.
The research was published in NanoLetters.