A5065475514- Silicon and Solar Cell Technologies
- Ion-surface interactions and analysis
- Integrated Circuits and Semiconductor Failure Analysis
- Semiconductor materials and interfaces
- Silicon Nanostructures and Photoluminescence
- Thin-Film Transistor Technologies
- Phase-change materials and chalcogenides
- Semiconductor materials and devices
- Chalcogenide Semiconductor Thin Films
- Glass properties and applications
- Laser Material Processing Techniques
- Nonlinear Optical Materials Studies
- Surface and Thin Film Phenomena
- Graphene research and applications
- Electron and X-Ray Spectroscopy Techniques
- nanoparticles nucleation surface interactions
- Advancements in Semiconductor Devices and Circuit Design
- X-ray Spectroscopy and Fluorescence Analysis
- Microstructure and mechanical properties
- Advanced Surface Polishing Techniques
- Advanced Optical Sensing Technologies
- Nanowire Synthesis and Applications
- Crystallography and Radiation Phenomena
- Intermetallics and Advanced Alloy Properties
- Advanced Materials Characterization Techniques
Institute for Microelectronics and Microsystems
2013-2022
University of Catania
2009-2021
National Research Council
2003-2021
Osservatorio Astrofisico di Catania
2009-2017
Paul Drude Institute for Solid State Electronics
2016
Consorzio Roma Ricerche
1997-2012
Istituto Nazionale di Fisica Nucleare, Sezione di Catania
1996-2007
University of Padua
2003
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2003
Istituto Nazionale per la Fisica della Materia
1968-2002
The transition to single crystal of ion-implanted amorphous Si and Ge layers is described in terms a liquid-phase epitaxy occurring during pulsing-laser irradiation. A standard heat equations including laser light absorption was solved numerically give the time evolution temperature melting as function pulse energy density its duration. structure dependence coefficient thermal conductivity were accounted for calculations. In this model occurs above well-defined threshold at which liquid...
The amorphous-to-crystal transition has been studied through in situ resistance measurements Ge2Sb2Te5 thin films doped by ion implantation with nitrogen or oxygen. dependence of the electrical resistivity and structure on annealing temperature time investigated samples different dopant concentrations. Enhancement thermal stability increase mobility gap for conduction have observed O- N-doped amorphous Ge2Sb2Te5. Larger effects found case doping.
Abstract Phase Change Materials (PCMs) are unique compounds employed in non-volatile random access memory thanks to the rapid and reversible transformation between amorphous crystalline state that display large differences electrical optical properties. In addition amorphous-to-crystalline transition, experimental results on polycrystalline GeSbTe alloys (GST) films evidenced a Metal-Insulator Transition (MIT) attributed disorder phase. Here we report fundamental advance fabrication of GST...
The time evolution of temperature and melting in amorphous silicon layers laser irradiated was calculated numerically. Experiments were performed Si crystals implanted with 400-keV As to a dose 5×1015/cm2 illuminated 50-ns-duration Q-switched ruby pulse the energy range 1.0–3.0 J/cm2. Comparison between experimental results allows quantitative understanding amorphous–to–single-crystal transition. A good agreement found profiles after irradiation those diffusion coefficient 10−4 cm2/s for...
A nanoscale investigation on the capacitive behavior of graphene deposited a SiO2/n+ Si substrate (with SiO2 thickness 300 or 100 nm) was carried out by scanning capacitance spectroscopy (SCS). bias Vg composed an AC signal and slow DC voltage ramp applied to macroscopic n+ backgate graphene/SiO2/Si capacitor, while contact obtained atomic force microscope tip. This study revealed that capacitor effective area (Aeff) responding is much smaller than geometrical sheet. related length scale...
Recently, giant carrier mobility μ (>10(5) cm(2) V(-1) s(-1)) and micrometer electron mean free path (l) have been measured in suspended graphene or encapsulated between inert ultraflat BN layers. Much lower values (10000-20000 are typically reported on common substrates (SiO(2), SiC) used for device fabrication. The debate the factors limiting is still open with charged impurities (CI) resonant scatterers (RS) indicated as most probable candidates. As a matter of fact, inhomogeneous...
The first comprehensive ion-backscattering study of the influence dislocations on dechanneling energetic channeled ions has been carried out. High dislocation densities were obtained in near-surface region single-crystal Al by implantation 6.6\ifmmode\times\else\texttimes\fi{}${10}^{16}$ Al/${\mathrm{cm}}^{2}$ or 2.6\ifmmode\times\else\texttimes\fi{}${10}^{16}$ Zn/${\mathrm{cm}}^{2}$. Independent analysis disorder introduced and Zn implantations, as well a quantitative measure total length...
Cu-implanted Si crystals were irradiated with $Q$-switched ruby-laser single pulses. After irradiation energy density in excess of 1.0 J/${\mathrm{cm}}^{2}$, the Cu atoms accumulate at sample surface. Thermal annealing 500-800\ifmmode^\circ\else\textdegree\fi{}C range casues a migration inside specimen, agreement diffusion coefficient and solid solubility values. The results indicate formation liquid layer induced by laser irradiation. solid-liquid interface movement during freezing...
The segregation phenomena of In-implanted Si have been observed following the melting and epitaxial regrowth surface layers by pulsed ruby laser irradiation. velocity liquid-solid interface on recrystallization has varied from 1.8 to 5.2 m/s in two independent ways. Indium is be trapped substitutional sites, excess solid solubilities, or segregated a thin layer. Trapping increases decreases as interfacial raised. complete depth profiles can fitted with unique coefficients which are...
Abstract Phase formation was studied in Au-A1 thin films by means of MeV He+ back-scattering and glancing angle X-ray diffraction techniques. In the initial stages compound formetion where both unreacted Au A1 layers are present, phases Au5Al2 Au2Al found. The end low-temperature treatments (150–300°C) AuAl2 or Au4Al presence only Al Au, respectively. kinetics growth Al-rich compounds follow a (time)1/2 dependence. activation energies for 1.0 1.2 eV,
Experiments are reported for Te and Ag implantation in silicon, as examples of slow fast diffusers, after furnace or laser annealing. Slow diffusers substitutionally located at concentrations great excess the maximum solid solubility both processes. Fast inhibit solid-phase epitaxial regrowth rejected sample surface irradiation. Although growth occurs with velocities which differ up to ten orders magnitude annealing, supersaturation is interpreted due same basic mechanism: solute trapping...
Channeling-effect measurements with 1.8-MeV helium ions on silicon samples doped arsenic to concentrations up 1.5×1021 atoms/cm3 indicate that greater than 90% of the atoms occupy substitutional lattice sites. A narrowing angular-yield profile is observed for in excess 1020 atoms/cm3. movement off sites after bombardment MeV ions. The initial rate (1017 As atoms/cm/μC) independent concentration. In arsenic-diffused subjected prolonged heat treatment at temperatures between 650–900°C an...
The dechanneled fractions of protons impinging along the $〈111〉$ and $〈110〉$ axial directions Si have been measured for ion energies between 0.3 1.5 MeV target temperatures ranging 80 423 \ifmmode^\circ\else\textdegree\fi{}K. fraction is a linear function penetration depth $z$. Its dependence on beam energy $E$ temperature $T$ can be described simply through parameter $\frac{z{\ensuremath{\rho}}^{2}}{E}$, ${\ensuremath{\rho}}^{2}$ being mean-square vibrational amplitude normal to row. All...
The mechanisms of He bubble and, after annealing, void formation have been investigated for single and multiple ${\mathrm{He}}^{+}$ implants in Si. Several analytical techniques adopted: photoluminescence (PL), Rutherford backscattering protons, transmission electron microscopy, atomic force microscopy. When a second implant is performed systematic enlargement the band reveals importance interaction between atoms point defects generated during irradiation. Size effects implanted region...
Design and fabrication of single photon avalanche detector (SPAD) in planar technology is reported. Device design critical issues the are discussed. Experimental test procedures described for dark-counting rate, afterpulsing probability, timing resolution, quantum detection efficiency. Low-noise detectors obtained, with dark counting rates down to 10 c/s devices /spl mu/m diameter, 1 kc/s 50 diameter. The suitable monolithic integration SPAD associated circuits.
The kinetics of the amorphous-to-crystal transition in Ge2Sb2Te5 thin films have been studied through situ transmission electron microscopy analyses. By following time evolution grain density and size, growth velocity nucleation rate separately measured at different annealing temperatures. Activation energies 2.9±0.5 eV 2.3±0.4 obtained for velocity, respectively. barrier energy a critical nucleus ΔG* has evaluated, scalability phase change nonvolatile memories estimated.
For the first time, memory devices with optimized high density (2E12#/cm/sup 2/) LPCVD Si nanocrystals have been reproducibly achieved and studied on an extensive statistical basis (from single cell up to 1 Mb test-array) under different programming conditions. An original experimental theoretical analysis of threshold voltage shift distribution shows that serious potential push scaling NOR NAND flash at least 35 nm 65 nodes, respectively.
The crystallization kinetics of as-deposited and ion implanted amorphous Ge2Sb2Te5 thin films has been measured by time resolved reflectivity. An enhancement the process occurred in samples. Raman scattering analysis was used to correlate stability phase its structure. variation signal after irradiation is consistent with a reduction Ge–Te tetrahedral bonds, characteristic Ge coordination Ge2Sb2Te5.