104 research outputs found
Sputtering of pure boron using a magnetron without a radio-frequency supply
Boron at room temperature is insulating and therefore conventionally sputtered using radio-frequency power supplies including their power-matching networks. In this contribution, we show that through a suitable ignition assistance, via temporary application of a high voltage (∼600 V) to the substrate holder or auxiliary electrode, the magnetron discharge can be ignited using a conventional mid-frequency power supply without matching network. Once the discharge is ignited, the assisting voltage can be reduced to less than 50 V, and after the boron target surface is at elevated temperature, thereby exhibiting sufficient conductivity, the assisting voltage can be turned off. The deposition of boron and boron nitride films has been demonstrated with a deposition rate of approximately 400 nm/h for a power of 250 W
Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications
This review presents an overview of the thermal properties of mesoscopic
structures. The discussion is based on the concept of electron energy
distribution, and, in particular, on controlling and probing it. The
temperature of an electron gas is determined by this distribution:
refrigeration is equivalent to narrowing it, and thermometry is probing its
convolution with a function characterizing the measuring device. Temperature
exists, strictly speaking, only in quasiequilibrium in which the distribution
follows the Fermi-Dirac form. Interesting nonequilibrium deviations can occur
due to slow relaxation rates of the electrons, e.g., among themselves or with
lattice phonons. Observation and applications of nonequilibrium phenomena are
also discussed. The focus in this paper is at low temperatures, primarily below
4 K, where physical phenomena on mesoscopic scales and hybrid combinations of
various types of materials, e.g., superconductors, normal metals, insulators,
and doped semiconductors, open up a rich variety of device concepts. This
review starts with an introduction to theoretical concepts and experimental
results on thermal properties of mesoscopic structures. Then thermometry and
refrigeration are examined with an emphasis on experiments. An immediate
application of solid-state refrigeration and thermometry is in ultrasensitive
radiation detection, which is discussed in depth. This review concludes with a
summary of pertinent fabrication methods of presented devices.Comment: Close to the version published in RMP; 59 pages, 35 figure
Controlled Transformation of Electrical, Magnetic and Optical Material Properties by Ion Beams
Key circumstance of radical progress for technology of XXI century is the
development of a technique which provides controllable producing
three-dimensional patterns incorporating regions of nanometer sizes and
required physical and chemical properties. Our paper for the first time
proposes the method of purposeful direct transformation of the most important
substance physical properties, such as electrical, magnetic, optical and others
by controllable modification of solid state atomic constitution.
The basis of the new technology is discovered by us effect of selective atom
removing out of thin di- and polyatomic films by beams of accelerated
particles. Potentials of that technique have been investigated and confirmed by
our numerous experiments. It has been shown, particularly, that selective atom
removing allows to transform in a controllable way insulators into metals,
non-magnetics into magnetics, to change radically optical features and some
other properties of materials.
The opportunity to remove selectively atoms of a certain sort out of solid
state compounds is, as such, of great interest in creating technology
associated primarily with needs of nanoelectronics as well as many other
"nano-problems" of XXI century.Comment: 22 pages, PDF, 9 figure
An Introduction to Array Logic
Abstract: After a discussion of the reasons for choosing to implement logic in array form. a detailed description of the nature of array logic is given. Topics specifically discussed include general array structures and implementation, influence of decoder partitioning
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