European scientists have started work on a project that will pave the way for the fabrication of low-energy devices operating at room temperature, which will, in turn, be a major boost for the operation of Internet of Things (IoT) devices.
The first meeting of all partners involved in this EU project is taking place between February 1 and 3, 2016 at the German research institute, Helmholtz-Zentrum Dresden-Rossendorf (HZDR). Other partners in addition to the HZDR, CEA-Leti and CSIC were the Fraunhofer Institute for Integrated Systems and Device Technology IISB in Erlangen in Germany, the Institute for Microelectronics and Microsystems IMM at the CNR in Italy and the University of Helsinki in Finland. The project funding is four million euro, according to a press release.
Caption: HZDR’s ion microscope produces a highly focused neon beam that allows for the local mixing of atoms in thin layered stacks. Tempering these stacks, silicon single quantum dots form on their own. Photo: HZDR / Oliver Killig
Foto: HZDR/Oliver Killig
The long-term goal of the HZDR was to conduct cutting-edge research in the areas of energy, health, and matter.
The program, which carries the project name, ‘ Ions4Set’, launched on February 1, involved partners from five European countries and was scheduled to run for four years.
Giving the background behind this fresh research, Dr. Karl-Heinz Heinig, initiator of the new EU project said transistors capable of switching information with a single electron used far less power than field effect transistors that were commonly used in today’s computers. However, these innovative electronic switches did not yet work at room temperature. Moreover, they were not compatible with the established production process in the field of microelectronics.
Billions of tiny computers will, in the future, communicate with each other via the Internet or locally. “Yet power consumption currently remained a great obstacle”, according to project coordinator Dr. Johannes von Borany, HZDR.
“Basically, there are two options: either one improves the batteries or one develops computer chips that require significantly less energy.” For example, it has been known for years that single electron transistors are an energy-saving alternative to the commonly used field effect transistors (FET). As yet, however, they only work at low temperatures and, what is more, they are not compatible with the so-called CMOS technology that forms the technological basis for the integration of a huge number of FET components on a computer chip necessary to perform complex signal processing at laptops or smartphones, he said in a statement.
The problem and its solution
The single electron transistor (SET) switches electricity by means of a single electron. The novel SET is based on a so-called quantum dot, consisting of just several hundred silicon atoms, embedded in an isolating layer that is sandwiched between two conducting layers. In order for an SET to function at room temperature, the silicon quantum dot needs to be smaller than five nanometers. Yet the electrons would not be able to pass through the transistor without another requirement being fulfilled: the distance between the quantum dot and the conducting layers must not be larger than two to three nanometers. As yet, these requirements could not be realized in nanoelectronics, said Dr Heinig.
“Our transistor is based on a nanopillar. We have discovered a mechanism that ensures that the silicon quantum dot virtually form on their own”, said Dr. Heinig.
“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.”
Leading European research institutions as well as the major players in the semiconductor industry, Globalfoundries, X-FAB and STMicroelectronics, have joined forces in the project to achieve the ability of reliably producing and reproducing billions of SET components made of nanopillars.
While CEA-Leti, a renowned French research institute for microelectronics, will produce the nanopillars, the Spanish National Centre for Microelectronics in Barcelona (CSIC) is commissioned to build the demonstrator that will constitute the conclusion of the four-year EU project.