Materials and Surfaces — M. Marakhtanov
18 Oct 2012
Mikhail Marahtanov, Ph.D., prof., the head of “Plasma devices” chair BMSTU
Plasma is considered as a mixture of electrons, ions, and neutral atoms or molecules. Usually, it has a low density (e.g., ~10-7 kg/m3), but charged particles in a plasma experience huge electromagnetic forces exerted by external sources. No mechanical device can provide such a strong acceleration like in plasmas. Therefore, plasma technology is usually employed when easily controllable fluxes of highly energetic particles need to be generated, yet one can deal with a relatively small amount of matter.
Plasma technologies have started with low-pressure glow discharges in vacuum tubes.
During the past century plasma technology has changed the world twice. First time it was when about 5.5 kg of 235U isotope have been obtained for the first atomic bomb. Major principles of the plasma technology used for this were further developed on thousands of plasma setups operating that time in Oak Ridge. Second time this happened around 1960, when vacuum tubes have been replaced with semiconductor elements and the term microelectronics has been adopted in the electronics industry, to underline small scales of the resulting devices.
Ion beam bent by the magnetic field in the isotope separator (left); transport system for ion beams 235U and 238U used in industrial separators, Oak Ridge, USA, 1944 (right).
Since then, highly energetic plasma ions became an invaluable technological tool. By using ion beams, one can spatter surfaces and coat them with thin conductive films, make holes in silicon wafers and very narrow channels between different elements, etc. Numerous kinds of hardware are being produced currently by employing plasma technology whose role is particularly important in optoelectronics: For instance, it allows us to create unusual optical products (such as, e.g., mobile phone screens) combining the properties of conductors (which are normally non-transparent) and dielectrics.
Applications of plasma technology: Thin conductive films in microchips; 85 nanometer holes produced with ion beams; plasma nitriding; thermoreflective coating for glass.
Plasma technology, which is now broadly used in mechanical engineering, aerospace industry, architecture, nanotechnology, etc. employs unique plasma properties which we will discuss in this lecture.
img src=”http://plasmacenter.bmstu.ru/wp-content/uploads/2012/08/03.jpg” alt=”" title=”03″ width=”77″ height=”134″ class=”aligncenter size-full wp-image-402″ /Начало плазменной технологии положила стеклянная трубка с тлеющим электрическим разрядом в разреженном газе./em