Thin crystal ferromagnetic films were synthesized by a team of scientists from Krasnoyarsk Scientific Center (Siberian Department of Russian Academy of Sciences) and Siberian Federal University in order to develop a technology for their shaping. Processed films can be employed in spintronic and electronic chips. The results of the study have been featured in Thin Solid Films journal.
This is the configuration of a thin crystal film. CREDIT: Anton Tarasov
The team developed films that are hundreds to dozens of nanometers thick. These films are produced from iron silicides synthesized on a silicon substrate. Iron silicides refer to compounds of silicon and iron that typically contain ferromagnetic properties when subject to specific temperatures. Non-magnetic iron silicides are also available with unique optic characteristics that may be put to practical use.
Such films are used as active parts in photonic and optic devices, and also in integral electronic and spintronic chips. Thin ferromagnetic films make room for a lot of prospects for spintronics (an area of science enabling the creation of information storage and processing devices). Devices like this are capable of consuming less electrical energy and have higher operating speed when compared to standard electronic ones.
However, to produce such devices scientists require films to be specially shaped. Meaning that a template will have to be applied to synthesized films, and they will have to be cut according to it. Scientists use etching to perform this task. It can be either dry (plasma, reactive-ion, or just ion) or wet (chemical). During the wet etching process, a film is placed in liquid - an etching agent capable of dissolving the rest of it. Prior to that, scientists cover the films with "masks" employing photolitography to set out essential configuration. Such a mask is capable of protecting the desired part of the film from dissolving. In dry etching process, the same result is brained by using a gas that destroys the material chemically or physically.
We've broadened the application of this approach, extended it to new iron-silicon alloys, and showed that it works. We've also determined the speed of etching and developed a micro-device. The same methods may be used for the production of different structures in electronics, photonics, and other applications.
Anton Tarasov, co-author of the article, candidate of physical and mathematical sciences, scientific associate of Kirensky Institute of Physics (FRC KSC of SD RAS), and senior tutor at Siberian Federal University.
Scientists highlight that a huge advantage of the new films refers to their magnetic and electronic properties, and also to their compatibility with the most popular technological semiconductors. This means, these films could be grown on bases made of germanium, silicon, and gallium arsenide. This will enable the team to obtain superior-quality thin films with particular shapes and geometry in a more affordable and simpler way. Furthermore, the obtained results lead to an increase in the selection of materials that scientists may employ for developing varied devices.
"Using this technology, one can create spintronic or photonic devices, because iron silicides have properties applicable in these areas of science. Right now we are growing new films and studying the effects that depend on their topology," concluded the scientist.
The team worked in association with scientists from Siberian State Aerospace University and Lomonosov Moscow State University. The research received grants from Russian Foundation for Basic Research and Krasnoyarsk Regional Science Foundation, and also worked with the grant of the President of the Russian Federation for the support of leading scientific establishments.