Antonio Terrasi

Bio: Antonio Terrasi is an academic researcher from University of Catania. The author has contributed to research in topics: Silicon & Thin film. The author has an hindex of 23, co-authored 116 publications receiving 1640 citations. Previous affiliations of Antonio Terrasi include University of Wisconsin-Madison & École Polytechnique.

Light absorption in silicon quantum dots embedded in silica

Abstract: The photon absorption in Si quantum dots (QDs) embedded in SiO2 has been systematically investigated by varying several parameters of the QD synthesis. Plasma-enhanced chemical vapor deposition (PECVD) or magnetron cosputtering (MS) have been used to deposit, upon quartz substrates, single layer, or multilayer structures of Si-rich-SiO2 (SRO) with different Si content (43–46 at. %). SRO samples have been annealed for 1 h in the 450–1250 °C range and characterized by optical absorption measurements, photoluminescence analysis, Rutherford backscattering spectrometry and x-ray Photoelectron Spectroscopy. After annealing up to 900 °C SRO films grown by MS show a higher absorption coefficient and a lower optical bandgap (∼2.0 eV) in comparison with that of PECVD samples, due to the lower density of Si–Si bonds and to the presence of nitrogen in PECVD materials. By increasing the Si content a reduction in the optical bandgap has been recorded, pointing out the role of Si–Si bonds density in the absorption proce...

Interaction between self-interstitials and substitutional C in silicon: Interstitial trapping and C clustering mechanism

Abstract: In this work the Si self-interstitial--carbon interaction has been experimentally investigated and modeled. The interactions between self-interstitials, produced by 20-keV silicon implantation, and substitutional carbon in silicon have been studied using a ${\mathrm{Si}}_{1\ensuremath{-}y}{\mathrm{C}}_{y}$ layer grown by molecular beam epitaxy (MBE) and interposed between the near-surface self-interstitial source and a deeper B spike used as a marker for the Si-interstitial concentration. The C atoms, all incorporated in substitutional sites and with a C-dose range of $7\ifmmode\times\else\texttimes\fi{}{10}^{12}--4\ifmmode\times\else\texttimes\fi{}{10}^{14}{\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}/\mathrm{c}\mathrm{m}}^{2},$ trap the self-interstitials in such a manner that the ${\mathrm{Si}}_{1\ensuremath{-}y}{\mathrm{C}}_{y}$ layer behaves as a filtering membrane for the interstitials flowing towards the bulk and, consequently, strongly reduces the boron-enhanced diffusion. This trapping ability is related to the total C dose in the ${\mathrm{Si}}_{1\ensuremath{-}y}{\mathrm{C}}_{y}$ membrane. Substitutional carbon atoms interacting with self-interstitials are shown to trap Si interstitials, to be removed from their substitutional sites, and to precipitate into the C-rich region. After precipitation, C atoms are not able to further trap injected self-interstitials, and the interstitials generated in the surface region can freely pass through the C-rich region and produce B-enhanced diffusion. The atomistic mechanism leading to Si-interstitial trapping has been investigated by developing a simulation code describing the migration of injected interstitials. The simulation takes into account the surface recombination, the interstitial diffusion in our MBE-grown material, and C traps. Since the model calculates the amount of interstitials that actually react with C atoms, by a comparison with the experimental data it is possible to derive quantitative indications of the trapping mechanism. It is shown that one Si interstitial is able to deactivate about two C traps by means of interstitial trapping and C clustering reactions. The reaction causing trapping and deactivation is tentatively described.

Evolution of the local environment around Er upon thermal annealing in Er and O co-implanted Si

Abstract: We present extended x-ray absorption fine structure (EXAFS) analyses of the Er LIII edge in Er-doped (100) Si samples. The samples were prepared by multiple implants of Er and O resulting in the incorporation of 1×1019 Er/cm3 and 1×1020 O/cm3 in a 2.3-μm-thick amorphous layer. It has been found that the local environment around the Er sites, which consists of six Si first neighbors in the amorphous layer, evolves towards a mixed coordination with O and Si atoms after epitaxial regrowth of the layer at 620 °C for 3 h. A further thermal treatment at 900 °C removes the residual Er–Si coordination and produces a full oxygen coordinated first shell with an average of 5 O neighbors. The effects of the different thermal processes on the high resolution spectra of the 1.54 μm Er photoluminescence were also measured and related to the EXAFS results.

Electrical and thermal transient during dielectric breakdown of thin oxides in metal-SiO2-silicon capacitors

Abstract: The dielectric breakdown of gate oxide layers with thickness of 35 and 93 nm in metal-oxide-semiconductor capacitors with a n+ polycrystalline Si/SiO2/n− Si stack was investigated Breakdown was characterized in a particular circuit configuration by following the time evolution of voltage, current, and power through the capacitor with a time resolution of the order of 2 ns A detailed morphological characterization of the damaged samples by emission and transmission electron microscopy is shown and discussed The results of the morphological analysis and of the electrical measurements are quantitatively discussed by simulating, through heat-flow calculations, the time evolution of the temperature in the regions interested to the breakdown phenomenon

Handbook of Chemistry and Physics

Abstract: There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Recent advances in Schottky barrier concepts

Abstract: Theoretical models of Schottky-barrier height formation are reviewed. A particular emphasis is placed on the examination of how these models agree with general physical principles. New concepts on the relationship between interface dipole and chemical bond formation are analyzed, and shown to offer a coherent explanation of a wide range of experimental data.

The physics and chemistry of the Schottky barrier height

Abstract: The formation of the Schottky barrier height (SBH) is a complex problem because of the dependence of the SBH on the atomic structure of the metal-semiconductor (MS) interface. Existing models of the SBH are too simple to realistically treat the chemistry exhibited at MS interfaces. This article points out, through examination of available experimental and theoretical results, that a comprehensive, quantum-mechanics-based picture of SBH formation can already be constructed, although no simple equations can emerge, which are applicable for all MS interfaces. Important concepts and principles in physics and chemistry that govern the formation of the SBH are described in detail, from which the experimental and theoretical results for individual MS interfaces can be understood. Strategies used and results obtained from recent investigations to systematically modify the SBH are also examined from the perspective of the physical and chemical principles of the MS interface.