16-07-2018 | | By Nnamdi Anyadike
The nano electronics market is strengthening on the back of a raft of new technologies and products such as mobile wireless devices, the internet of things (IoT) and cloud computing. A useful working definition for nano electronics is that branch of electronics, which utilises nanotechnology less than 100nm in size.
One major driver in this market is the development of molecular electronics. This is the use of molecules as the primary building block for electronic circuitry. Another key driver is the development of ‘spintronics’. This is a new area of research, based on the spin of electrons, and which has given rise to the concept of "spintronic devices." These devices run on electron spins, rather than their charge as is the case with traditional electronics.
A plot showing a spin up, spin down, and the resulting spin polarized population of electrons. Inside a spin injector, the polarization is constant, while outside the injector, the polarization decays exponentially to zero as the spin up and down populations go to equilibrium.
The Swiss-based research institute and university, Ecole Polytechnique Fédérale de Lausanne, is currently undertaking research into the physics of spintronics. And in June a white paper it claimed that it has now been able to demonstrate the ability to control what it calls "the spin landscape", using electric fields. This was accomplished by using a new class of materials based on germanium telluride (GeTe).
The New York headquartered Institute of Electrical and Electronics Engineers (IEEE) is also involved in nanoelectronics. Under the aegis of the NanoElectronics Roadmap for Europe: Identification and Dissemination (NEREID, Horizon 2020), it is working together with a number of partners in Japan and Europe on a roadmap. Memorandums of understanding (MoUs) were recently signed with the SiNANO Institute in Europe; the Systems and Devices Roadmap committee of Japan (SDRJ); and the Japan Society of Applied Physics (JSAP).
Other initiatives include that being undertaken by the US-based Nanotechnology Signature Initiative (NSI). Its stated aim is “to accelerate the discovery and use of novel nanoscale fabrication processes and innovative concepts to produce revolutionary materials, devices, systems, and architectures to advance the field of nanoelectronics.”
Meanwhile, scientists from Tomsk Polytechnic University based in Tomsk, Russia and their colleagues from Germany are conducting research into the use of gold nanoantennas to create more powerful nanoelectronics. They see applications for this technology in the creation of flexible displays for smartphones, optical and computing schemes and solar cells.
Professor Raul Rodrigez from the Department of Lasers and Lighting Technology who is one of the researchers said, "Nowadays, there are modern technologies that enable the creation of transistors with a channel width of 12 to 14 nanometers...we should understand how the semiconductor material behaves when interacting with metals and how its properties change at the nanoscale." For their study the scientists used gold nanotriangles with two monolayers of molybdenum disulphide placed on top of them. "It's very important to understand what happens when a semiconductor (molybdenum disulfide) contacts a conductor (gold) if we want to create a nanodevice," explained Rodrigez.
The military is also keen to take advantage of nanoelctronics. And the US’ Air Force Research Laboratory (AFRL) is targeting research programmes to investigate nanoelectronics materials, through its Materials and Manufacturing Directorate. The directorate is examining the potential merger of nanoelectronics and nanophotonics.
But it is not just academia and the defence establishment where advances in nanoelectronic are being made. A number of companies are also now stepping up their efforts to develop commercial devices. This January, Russia-based Crocus Nano Electronics (CNE) announced successful test results for its 90 nm pMTJ STT-MRAM technology. Then in June, it announced its collaboration with the California-based Adesto Technologies and China’s Shanghai Huali Microelectronics (HLMC) to work on ReRAM technology.
Adesto is developing this technology, called Conductive Bridging RAM (CBRAM). Under the planned collaboration, CBRAM will be manufactured in HLMC’s 55nm facility, along with CNE’s 300mm back-end processing technology. The goal is to enable embedded and standalone ReRAM memory devices. HLMC describes 55nm as “the sweet spot” for low-power, economical silicon platforms for IoT edge nodes. Jack Qi Shu at HLMC said, “We anticipate ramping quickly to production in 55nm and are also exploring a potential roadmap for even more advanced nodes.”
Yet despite these advances, electronic component downsizing towards the nanoscale continues to present a formidable challenge for electronics. A major problem stems from one of the basic laws of physics. All electronic devices work by the shuttling of electric charges around their circuits. But as individual components get smaller it becomes increasingly difficult to precisely channel these electric charges to where they’re needed. And at the nanoscale, a single atom can influence or disrupt the flow of electrons.
By offering high efficiency and low power dissipation molecular electronics devices are seen as an important solution to this problem. There are though disadvantages that still need to be overcome. These include high manufacturing costs and the lack of an appropriately skilled workforce. Nonetheless, progress in dealing with these challenges is continuing apace. And the electronics industry has every reason to be optimistic that by the next decade, the use of molecular electronic devices will have become ubiquitous.