S. Mirabella - Academia.edu (original) (raw)
Papers by S. Mirabella
Journal of Applied Physics, 2000
The structural, electrical, and optical properties of crystalline Si codoped with Er and O by mol... more The structural, electrical, and optical properties of crystalline Si codoped with Er and O by molecular beam epitaxy (MBE) have been investigated in detail. Si:Er:O layers (∼250 nm thick) have been grown by MBE, realizing uniform dopant concentrations in the range for Er and up to for ...
B diffusion measurements are used to probe the basic nature of self-interstitial point defects in... more B diffusion measurements are used to probe the basic nature of self-interstitial point defects in Ge. We find two distinct self-interstitial forms-a simple one with low entropy and a complex one with entropy $30 k at the migration saddle point. The latter dominates diffusion at high temperature. We propose that its structure is similar to that of an amorphous pocket-we name it a morph. Computational modeling suggests that morphs exist in both self-interstitial and vacancylike forms, and are crucial for diffusion and defect dynamics in Ge, Si, and probably many other crystalline solids.
2014 IEEE 9th Nanotechnology Materials and Devices Conference (NMDC), 2014
Solid State Phenomena, 2004
... F. Priolo 1 1 INFM and Department of Physics and Astronomy, University of Catania, Via S. Sof... more ... F. Priolo 1 1 INFM and Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; e-mail: giannazzo@imm.cnr.it 2 CNR-IMM, Stradale Primosole 50, 95121 Catania, Italy; e-mail: raineri@imm.cnr.it ...
Solid State Phenomena, 2005
... Italy 2 MATIS-INFM and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sof... more ... Italy 2 MATIS-INFM and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, I-95123 Catania, Italy 3 MATIS-INFM and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, I-35131 Padova, Italy ...
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 2009
ABSTRACT In this paper we discuss from an atomistic point of view some of the issues involved in ... more ABSTRACT In this paper we discuss from an atomistic point of view some of the issues involved in the modeling of electrical characteristics evolution in silicon devices as a result of ion implantation and annealing processes in silicon. In particular, evolution of electrically active dose, sheet resistance and hole mobility has been investigated for high B concentration profiles in pre-amorphized Si. For this purpose, Hall measurements combined with atomistic kinetic Monte Carlo atomistic simulations have been performed. An apparent anomalous behavior has been observed for the evolution of the active dose and the sheet resistance, in contrast to opposite trend evolutions reported previously. Our results indicate that this anomalous behavior is due to large variations in hole mobility with active dopant concentration, much larger than that associated to the classical dependence of hole mobility with carrier concentration. Simulations suggest that hole mobility is significantly degraded by the presence of a large concentration of boron-interstitial clusters, indicating the existence of an additional scattering mechanism. Copyright © 2009 John Wiley & Sons, Ltd.
Applied Physics Letters, 2015
Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (V o ) were identified... more Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (V o ) were identified in ZnO nanorods (NRs) grown by low cost chemical bath deposition. A transient behaviour in the photoluminescence (PL) intensity of the two V o states was found to be sensitive to the ambient environment and to NR postgrowth treatment. The largest transient was found in samples dried on a hot plate with a PL intensity decay time, in air only, of 23 and 80 s for the 2.25 and 2.03 eV peaks, respectively. Resistance measurements under UV exposure exhibited a transient behaviour in full agreement with the PL transient indicating a clear role of atmospheric O 2 on the surface defect states. A model for surface defect transient behaviour due to band bending with respect to the Fermi level is proposed. The results have implications for a variety of sensing and photovoltaic applications of ZnO NRs.
CLEO: 2014, 2014
ABSTRACT Photocurrent enhancement in thin a-Si:H solar cells due to the plasmonic light trapping ... more ABSTRACT Photocurrent enhancement in thin a-Si:H solar cells due to the plasmonic light trapping is investigated, and correlated with the morphology and the optical properties of the self-assembled silver nanoparticles incorporated in the cells’ back reflector.
Applied Physics Letters, 2014
ABSTRACT Flexible sensors are gaining increasing interest in a number of applications, including ... more ABSTRACT Flexible sensors are gaining increasing interest in a number of applications, including biomedical, food control, domotics and robotics, having very light weight, robustness and low cost. Low temperature polycrystalline silicon (LTPS) technology is particularly attractive for such applications, since LTPS TFTs show excellent electrical characteristics, good stability and offer the possibility to exploit CMOS architectures. Then, as examples of flexible sensing systems, we present a tactile sensor for robotic applications and a pH sensor for biomedical applications. The present results can pave the way to advanced flexible sensing systems, where sensors and local signal conditioning circuits can be integrated on the same flexible substrate.
Materials Science in Semiconductor Processing, 2005
In this paper we compare dry oxidation, at different temperatures and oxidation times, on epitaxi... more In this paper we compare dry oxidation, at different temperatures and oxidation times, on epitaxial SiGe films and Si reference samples. Rapid and conventional furnaces and several analysis techniques, such as Rutherford backscattering spectrometry, transmission electron microscopy and secondary ion mass spectroscopy, have been used to process and characterize our samples. We focused the attention on the thin oxide regime
15th IEEE International Conference on Advanced Thermal Processing of Semiconductors, RTP 2007, 2007
ABSTRACT In this work we demonstrate that He co-implantation can be a powerful tool to control B ... more ABSTRACT In this work we demonstrate that He co-implantation can be a powerful tool to control B diffusion in crystalline silicon (c-Si). In particular, the He induced damage leads to the formation of a distribution of nanovoids near the surface that locally suppress the amount of self-interstitials (Is) generated by further B implantation. Thus, B diffusion is reduced and the B implanted profile assumes a box-like shape. In particular, we analyze the microscopic mechanisms leading to the implanted B -nanovoids interaction, demonstrating that the Is injected from the B implanted region annihilate at nanovoids while eroding the nanovoid front layer. By means of a simulation of B diffusion, we will demonstrate that the consequent non-uniform interstitial supersaturation within the sample determines the peculiar B box-like shape, which is particularly appealing for device fabrication.
Journal of Applied Physics, 2000
The structural, electrical, and optical properties of crystalline Si codoped with Er and O by mol... more The structural, electrical, and optical properties of crystalline Si codoped with Er and O by molecular beam epitaxy (MBE) have been investigated in detail. Si:Er:O layers (∼250 nm thick) have been grown by MBE, realizing uniform dopant concentrations in the range for Er and up to for ...
B diffusion measurements are used to probe the basic nature of self-interstitial point defects in... more B diffusion measurements are used to probe the basic nature of self-interstitial point defects in Ge. We find two distinct self-interstitial forms-a simple one with low entropy and a complex one with entropy $30 k at the migration saddle point. The latter dominates diffusion at high temperature. We propose that its structure is similar to that of an amorphous pocket-we name it a morph. Computational modeling suggests that morphs exist in both self-interstitial and vacancylike forms, and are crucial for diffusion and defect dynamics in Ge, Si, and probably many other crystalline solids.
2014 IEEE 9th Nanotechnology Materials and Devices Conference (NMDC), 2014
Solid State Phenomena, 2004
... F. Priolo 1 1 INFM and Department of Physics and Astronomy, University of Catania, Via S. Sof... more ... F. Priolo 1 1 INFM and Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, 95123 Catania, Italy; e-mail: giannazzo@imm.cnr.it 2 CNR-IMM, Stradale Primosole 50, 95121 Catania, Italy; e-mail: raineri@imm.cnr.it ...
Solid State Phenomena, 2005
... Italy 2 MATIS-INFM and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sof... more ... Italy 2 MATIS-INFM and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, I-95123 Catania, Italy 3 MATIS-INFM and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, I-35131 Padova, Italy ...
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 2009
ABSTRACT In this paper we discuss from an atomistic point of view some of the issues involved in ... more ABSTRACT In this paper we discuss from an atomistic point of view some of the issues involved in the modeling of electrical characteristics evolution in silicon devices as a result of ion implantation and annealing processes in silicon. In particular, evolution of electrically active dose, sheet resistance and hole mobility has been investigated for high B concentration profiles in pre-amorphized Si. For this purpose, Hall measurements combined with atomistic kinetic Monte Carlo atomistic simulations have been performed. An apparent anomalous behavior has been observed for the evolution of the active dose and the sheet resistance, in contrast to opposite trend evolutions reported previously. Our results indicate that this anomalous behavior is due to large variations in hole mobility with active dopant concentration, much larger than that associated to the classical dependence of hole mobility with carrier concentration. Simulations suggest that hole mobility is significantly degraded by the presence of a large concentration of boron-interstitial clusters, indicating the existence of an additional scattering mechanism. Copyright © 2009 John Wiley & Sons, Ltd.
Applied Physics Letters, 2015
Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (V o ) were identified... more Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (V o ) were identified in ZnO nanorods (NRs) grown by low cost chemical bath deposition. A transient behaviour in the photoluminescence (PL) intensity of the two V o states was found to be sensitive to the ambient environment and to NR postgrowth treatment. The largest transient was found in samples dried on a hot plate with a PL intensity decay time, in air only, of 23 and 80 s for the 2.25 and 2.03 eV peaks, respectively. Resistance measurements under UV exposure exhibited a transient behaviour in full agreement with the PL transient indicating a clear role of atmospheric O 2 on the surface defect states. A model for surface defect transient behaviour due to band bending with respect to the Fermi level is proposed. The results have implications for a variety of sensing and photovoltaic applications of ZnO NRs.
CLEO: 2014, 2014
ABSTRACT Photocurrent enhancement in thin a-Si:H solar cells due to the plasmonic light trapping ... more ABSTRACT Photocurrent enhancement in thin a-Si:H solar cells due to the plasmonic light trapping is investigated, and correlated with the morphology and the optical properties of the self-assembled silver nanoparticles incorporated in the cells’ back reflector.
Applied Physics Letters, 2014
ABSTRACT Flexible sensors are gaining increasing interest in a number of applications, including ... more ABSTRACT Flexible sensors are gaining increasing interest in a number of applications, including biomedical, food control, domotics and robotics, having very light weight, robustness and low cost. Low temperature polycrystalline silicon (LTPS) technology is particularly attractive for such applications, since LTPS TFTs show excellent electrical characteristics, good stability and offer the possibility to exploit CMOS architectures. Then, as examples of flexible sensing systems, we present a tactile sensor for robotic applications and a pH sensor for biomedical applications. The present results can pave the way to advanced flexible sensing systems, where sensors and local signal conditioning circuits can be integrated on the same flexible substrate.
Materials Science in Semiconductor Processing, 2005
In this paper we compare dry oxidation, at different temperatures and oxidation times, on epitaxi... more In this paper we compare dry oxidation, at different temperatures and oxidation times, on epitaxial SiGe films and Si reference samples. Rapid and conventional furnaces and several analysis techniques, such as Rutherford backscattering spectrometry, transmission electron microscopy and secondary ion mass spectroscopy, have been used to process and characterize our samples. We focused the attention on the thin oxide regime
15th IEEE International Conference on Advanced Thermal Processing of Semiconductors, RTP 2007, 2007
ABSTRACT In this work we demonstrate that He co-implantation can be a powerful tool to control B ... more ABSTRACT In this work we demonstrate that He co-implantation can be a powerful tool to control B diffusion in crystalline silicon (c-Si). In particular, the He induced damage leads to the formation of a distribution of nanovoids near the surface that locally suppress the amount of self-interstitials (Is) generated by further B implantation. Thus, B diffusion is reduced and the B implanted profile assumes a box-like shape. In particular, we analyze the microscopic mechanisms leading to the implanted B -nanovoids interaction, demonstrating that the Is injected from the B implanted region annihilate at nanovoids while eroding the nanovoid front layer. By means of a simulation of B diffusion, we will demonstrate that the consequent non-uniform interstitial supersaturation within the sample determines the peculiar B box-like shape, which is particularly appealing for device fabrication.