Feb 1 2016
Credit - Alexandru Nika/Shutterstock.com
The ‘Internet of Things’ is witnessing a rapid growth. Minicomputers linked to items, such as mobile phones, a milk bottle in the fridge, and washing machines can process information, send and receive data.
All of this requires electrical power, and transistors capable of switching information using a single electron, utilize less power compared to field effect transistors, which are commonly employed in computers.
These electronic switches do not work at room temperature and they are also not compatible with the production process prevalent in microelectronics field. Researchers working on a new EU project called ‘Ions4Set,’ are aiming to change this situation. The new project will begin on February 1 for a duration of four years and it will involve collaborators from five European nations. The project will be coordinated by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR).
Billions of tiny computers will in future communicate with each other via the Internet or locally. Yet power consumption currently remains a great obstacle. Basically, there are two options: either one improves the batteries or one develops computer chips that require significantly less energy.
Dr. Johannes von Borany, Project Coordinator, HZDR
It is known that single electron transistors (SETs) are an energy-saving alternative the common field effect transistors (FETs). However, SETs only work at low temperatures and they are incompatible with the CMOS technology. The CMOS technology forms the basis for integrating several FET components on a computer chip to enable complex signal processing at smartphones or laptops.
The SET switches electricity using a single electron. The unique SET is based on a ‘quantum dot’ (consisting of large number of silicon atoms) set in an isolating layer that is packed between two conducting layers. For room temperature functioning of an SET, the quantum dot should be smaller than five nanometers. Another requirement still has to be fulfilled for the electrons to pass through the transistor: the distance between the conducting layers and the quantum dot must not be more than two to three nanometers. These conditions have not yet been realized in nanoelectronics.
Our transistor is based on a nanopillar. We have discovered a mechanism that ensures that the silicon quantum dot virtually form on their own. We construct slim silicon pillars of about 20 nanometers into which we embed a six nanometer thin layer consisting of the isolator silicon dioxide. Silicon atoms are pushed into the isolator by irradiating the nanopillar with fast, charged particles. When the structures are subsequently subjected to strong heat, the atoms cluster at the center of the isolating layer to form a single silicon quantum dot.
Dr. Karl-Heinz Heinig, Initiator of the new EU project
Well-known European research institutions, and leaders in the semiconductor industry, GlobalFoundries, X-FAB and STMicroelectronics, are participating in the project to reliably produce and reproduce billions of SET components made up of nanopillars.
While CEA-Leti, a well-known research institute for microelectronics, will produce the nanopillars of a very small size, the Spanish National Centre for Microelectronics in Barcelona (CSIC) will build the demonstrator that constitutes the conclusion of the four-year EU project. However, the researchers’ task is far more complex; the demonstrator cannot comprise of just the SET components that perform the room temperature logical operations. Classical FET components are also a required, in the form of nanopillars. This is because the energy-saving SETs have very little power present to interact outside of their own chip. The chip that facilitates the advance of the ‘Internet of Things’ should contain FET in addition to SET nanopillars, so that the FET can transmit the outcomes of the SET operations to other devices and chips.
The first meeting of the collaborative partners involved in the project is scheduled to be held from February 1 to 3, 2016 at the HZDR. Other partners besides the HZDR, CEA-Leti and CSIC, are the Fraunhofer Institute for Integrated Systems and Device Technology IISB, Erlangen, Germany; the Institute for Microelectronics and Microsystems IMM at the CNR, Italy; and the University of Helsinki, Finland. The project is expected to cost four million euro.
We are convinced of successfully completing the new project. On the one hand, we draw on insights from a previous EU project with computer chip producers; on the other, we were able to win over the leading research institutions in this field to be our partners. After the successful completion of the project, it will be straightforward for the microelectronics industry to adopt our manufacturing technique as fully compatible with CMOS technology.
Dr. Karl-Heinz Heinig, Initiator of the new EU project