A5088601609- Semiconductor materials and devices
- Silicon Carbide Semiconductor Technologies
- Silicon Nanostructures and Photoluminescence
- Semiconductor materials and interfaces
- Luminescence Properties of Advanced Materials
- Ga2O3 and related materials
- Thin-Film Transistor Technologies
- Diamond and Carbon-based Materials Research
- Copper Interconnects and Reliability
- Photonic and Optical Devices
- ZnO doping and properties
- Advanced ceramic materials synthesis
- Aluminum Alloys Composites Properties
- Photonic Crystals and Applications
- Graphene research and applications
STMicroelectronics (Italy)
2020-2025
STMicroelectronics (Switzerland)
2024
University of Catania
2011-2015
Institute for Microelectronics and Microsystems
2011-2015
In this paper, we investigated the effects of processing parameters, such as deposition methods, annealing temperature, and metal thickness, on electrical characteristics Ti/4H-SiC contacts. A reduction Schottky barrier height from 1.19 to 1.00 eV following an increase temperature (475–700 °C) was observed for a reference contact with 80 nm-thick Ti layer. The current transport mechanisms can be described according thermionic emission (TE) field (TFE) models under forward reverse biases,...
A stable Eu3+ → Eu2+ reduction is accomplished by thermal annealing in N2 ambient of Eu2O3 films deposited magnetron sputtering on Si substrates. Transmission electron microscopy and x-ray diffraction measurements demonstrate the occurrence a complex reactivity at Eu2O3/Si interface, leading to formation silicates, characterized very strong (the measured external quantum efficiency about 10%) broad room temperature photoluminescence (PL) peak centered 590 nm. This signal much more efficient...
The comparison of the performances SiO2 and SiOC layers as host matrices for optically active Eu ions is presented. A matrix allows to observe light emission from both Eu2+ Eu3+ ions, owing a proper tuning thermal annealing process used optical activation rare earth. However, photoluminescence efficiency remains relatively low quite far requirements technological applications, mainly due extensive formation Eu-containing precipitates. detailed study by transmission electron microscopy...
Abstract In this paper, the electrical behavior of tungsten carbide (WC) Schottky barrier on 4H-SiC was investigated. First, a statistical current-voltage (I–V) analysis in forward bias, performed set equivalent diodes, showed symmetric Gaussian-like distribution heights after annealing at 700 °C, where low height (Φ B = 1.05 eV) and an ideality factor n 1.06 were measured. The value makes such WC contact interesting candidate to reduce conduction losses diodes. A deeper characterization has...
The intense luminescence of SiOC layers is studied and its dependence on the parameters thermal annealing process elucidated. Although emission bright enough to be interesting for practical applications, this material even more promising as a host matrix optically active Eu ions. Indeed, when incorporated in matrix, Eu(3+) ions are efficiently reduced Eu(2+), producing very strong visible peaked at 440 nm. Eu(2+) benefit also occurrence an energy transfer mechanism involving which increases...
This paper reports on the effects of excimer laser irradiation an aluminum (Al)-doped silicon carbide (4H-SiC) layer. Specifically, high-concentration (1 × 1020 at/cm3) Al-implanted 4H-SiC samples were exposed to a few pulses 308 nm radiation (pulse duration 160 ns), with fluence varying from 1.0 2.8 J/cm2. As starting point, laser-induced modifications morphological, microstructural, and nanoelectrical properties surface monitored by combining different techniques. From these...
Bilayers consisting of two SiOC films doped with Eu at different concentrations have been synthesized by magnetron cosputtering. The proper choice annealing temperature allows us to avoid diffusion and clustering, so that each layer maintains its optical properties. Under these conditions, the bilayer take advantage dependence photoluminescence peak position on concentration, an intense white emission is obtained room temperature. This finding constitutes relevant progress towards...
The formation of ohmic contacts by laser annealing approach is great importance for SiC power devices, since it allows their fabrication on thin substrates, that crucial significance to reduce dissipation. Ni silicide reaction under UV irradiation has been studied in detail with particular focus single pulse approach, order describe the early stage process. use a multi silicide-based means excimer annealing, investigated this work. process characterized, as function number pulses, X-Ray...
New generations of SiC power devices require to be fabricated on very thin substrates, in order significantly reduce the series resistance device. The role thinning process formation backside ohmic contact has been investigated this work. Three different mechanical grinding processes have adopted, resulting amounts defectivity and surface roughness values. An excimer UV laser used form a Ni-silicide based wafers. reacted layer studied by means Atomic Force Microscopy (AFM), Transmission...
In this paper, we investigate the electrical evolution of tungsten (W) and carbide (WC) Schottky contacts on 4H-SiC subjected to thermal treatments at different annealing temperatures from 475 700 {\deg} C. For each temperature, uniformity barrier height (${\phi_B}$) ideality factor (n) was monitored by current-voltage (I-V) measurements in forward bias, performed over sets equivalent diodes. Good values n (below 1.05) were found for both up On other hand, two behaves differently. W/4H-SiC...
We report on the investigation of structural, chemical and optical properties undoped Eu-doped SiOC thin films synthetized by RF magnetron sputtering. Undoped exhibits an intense room temperature luminescence at ~ 500 nm, important contribution to this signal is due presence Si-C bonds. Moreover, when inserted in a matrix, Eu ions have higher solid solubility with respect pure SiO2; as consequence, we observe reduction clustering phenomena. Furthermore reducing SiOC, related C, allow...
A very bright room-temperature cathodoluminescence (CL) signal, tunable in the visible range by changing Eu(2+) concentration, has been observed Eu-doped SiOC films. Depth-resolved CL measurements demonstrate that a bilayer consisting of two films containing different Eu concentrations allows continuous tuning emission from blue to green energy exciting electrons. Furthermore, proper control at nanoscale electron penetration depth obtain high-quality white light emission. The compatibility...
Laser annealing process for ohmic contact formation on 4H-SiC has attracted increasing attention in the last years, because it enables fabrication of SiC power devices very thin substrates. We have investigated Nickel-based by using a Yb:YAG laser scanning mode, with wavelength 515 nm and pulse duration 1200 ns. A 100 thick Ni layer been deposited irradiated at different conditions. The reaction studied, as function fluence scan number annealing, means X-Ray Diffraction (XRD) Transmission...
We report on a promising approach to realize bifacial silicon carbide (SiC) based ultraviolet (UV) photodetectors with no metallic electrodes. The ohmic contact regions, consisting of few conductive carbon-rich layers, while maintaining the necessary UV sensitivity for photodetector's operation, are directly realized using nanosecond-pulsed excimer laser. By combining structural, optical, and electrical characterization, we demonstrate how this treatment allows formation contacts, both front...
Composition and morphology of two types bilayers plasma‐enhanced chemical vapor deposition hydrogened silicon nitride (SiN x :H) polyimide (PI), as effcient barrier against moisture in SiC‐based power devices, are investigated. Two nitrides obtained by changing the flow ratios SiH 4 NH 3 precursors. Rutherford Backscatterered analyses show that Si/N ratio varies from 0.6 to 0.8. Elastic recoil detection sample with higher nitrogen content has a total bound hydrogen 7.8 × 10 17 cm −2 respect...
Silicon carbide (SiC) is a wide bandgap semiconductor suitable for high-voltage, high-power and high-temperature applications. However, the production of advanced SiC power devices still remains limited due to some shortcomings dielectric properties passivation layer. Thanks their high operating temperature strength, spin coated polyimide (PI) layers are considered ideal candidates insulation. In this view, robust methodology physico-chemical characterization such PI required. use time...
In this paper, we explore the effects of excimer laser irradiation on heavily Aluminum (Al)-implanted silicon carbide (4H-SiC) layer. 4H-SiC layers were exposed to UV-laser radiation (308 nm, 160 ns), at different fluences and exposure surface evaluated from morphological, micro-structural nano-electrical standpoints. Depending condition, significant near-surface changes observed. Moreover, electrical characteristics implanted layer, by means transmission line method, gave a sheet-resistance...
A promising approach to obtain light emission from Si-based materials is represented by doping with rare earths and in particular Eu. In this paper the comparison of performances SiO<sub>2</sub> SiOC layers as host matrices for optically active Eu ions presented. matrix allows observe both Eu<sup>2+</sup> Eu<sup>3+</sup> ions, owing a proper tuning thermal annealing process used activate earth. However photoluminescence efficiency remains relatively low quite far requirements technological...
We present the different approaches we recently followed to achieve intense room temperature photoluminescence (PL) from Si-based materials. On one side obtained sub-bandgap PL H-related defects induced by H2 plasma treatment of Si photonic crystal (PhC) nanocavities. demonstrated that a strong and narrow emission can be in PhC nanocavities due formation damaged layer mainly consisting nanometric platelets bubbles. An overall 40000-fold enhancement signal, with respect pure crystalline Si,...