In this letter we present the results regarding the electrical and optical characterization of Geiger mode silicon avalanche photodiodes(GMAP) fabricated by silicon standard planar technology. Low dark count rates,neg...In this letter we present the results regarding the electrical and optical characterization of Geiger mode silicon avalanche photodiodes(GMAP) fabricated by silicon standard planar technology. Low dark count rates,negligible afterpulsing effects,good timing resolution and high quantum detection efficiency in all the visible range have been measured. The very good electro-optical performances of our photodiodes make them attractive for the fabrication of arrays with a large number of GMAP to be used both in the commercial and the scientific fields,as telecommunications and nuclear medical imaging.展开更多
This article gives an overview of the main passive solutions and active techniques, based on AC switches to limit inrush currents in medium power AC-DC converters （up to 3.7 kW） for electric vehicle charging systems...This article gives an overview of the main passive solutions and active techniques, based on AC switches to limit inrush currents in medium power AC-DC converters （up to 3.7 kW） for electric vehicle charging systems. In particular, a strategy, based on SCR （silicon controlled rectifier） phase, shift control in a mixed rectifier bridge with diodes and thyristors, is proposed. The challenge is to help designers optimize the triggering delay of SCRs to both limit the peak value of inrush current spikes and optimize the charge duration of the DC-link capacitor. A mathematical model （Mathcad engineering tool） has been defined to point out, the interest of a variable triggering delay to control SCRs to meet the expectations described previously. Experimental measurements using an industrial evaluation board of the AC-DC converter demonstrate the robustness of the method.展开更多
Rapid prototyping methods for the design and fabrication of polymeric labs-on-a-chip are on the rise,as they allow high degrees of precision and flexibility.For example,a microfluidic platform may require an optimizat...Rapid prototyping methods for the design and fabrication of polymeric labs-on-a-chip are on the rise,as they allow high degrees of precision and flexibility.For example,a microfluidic platform may require an optimization phase in which it could be necessary to continuously modify the architecture and geometry;however,this is only possible if easy,controllable fabrication methods and low-cost materials are available.In this paper,we describe the realization process of a microfluidic tool,from the computer-aided design(CAD)to the proof-of-concept application as a capture device for circulating tumor cells(CTCs).The entire platform was realized in polymethyl methacrylate(PMMA),combining femtosecond(fs)laser and micromilling fabrication technologies.The multilayer device was assembled through a facile and low-cost solvent-assisted method.A serpentine microchannel was then directly biofunctionalized by immobilizing capture probes able to distinguish cancer from non-cancer cells without labeling.The low material costs,customizable methods,and biological application of the realized platform make it a suitable model for industrial exploitation and applications at the point of care.展开更多
We present the properties and potentialities of light emitting devices based on amorphous Si nanoclusters. Amorphousnanostructures may constitute an interesting alternative to Si nanocrystals for the monolithic integr...We present the properties and potentialities of light emitting devices based on amorphous Si nanoclusters. Amorphousnanostructures may constitute an interesting alternative to Si nanocrystals for the monolithic integration of optical andelectrical functions in Si technology. In fact, they exhibit an intense room temperature electroluminescence (EL). The ELproperties of these devices have been studied as a function of current and of temperature. Moreover, to improve theextraction efficiency of the light, we have integrated the emitting system with a 2D photonic crystal structure opportunelyfabricated by using conventional optical lithography to reduce the total internal reflection of the emitted light. The extractionefficiency in such devices increases by a factor of 4 at a resonance wavelength.展开更多
Cz n-type Si (100) samples with and without a top SiO2 layer were implanted with 40 keV helium ions at the same dose of 5×1016 cm-2. Cross-sectional transmission electron microscopy (XTEM) and thermal desorption ...Cz n-type Si (100) samples with and without a top SiO2 layer were implanted with 40 keV helium ions at the same dose of 5×1016 cm-2. Cross-sectional transmission electron microscopy (XTEM) and thermal desorption spectroscopy (THDS) were used to study the thermal evolution of cavities upon and helium thermal release, respectively. XTEM results show that the presence of the top SiO2 layer could suppress the thermal growth of cavities mainly formed in the region close to the SiO2/Si interface, which leads to the reduction in both the cavity band and cavity density. THDS results reveal that the top oxide layer could act as an effective barrier for the migration of helium atoms to the surface, and it thus gives rise to the formation of more overpresurrized bubbles and to the occurrence of a third release peak located at about 1100 K. The results were qualitively discussed by considering the role of the oxide surface layer in defect migration and evolution upon annealing.展开更多
We present a nonlinear event-driven model of a Digital PLL used in the context of a polar modulation. This modeling has shown that the estimation method of the TDC gain has a big impact on the EVM for wideband modulat...We present a nonlinear event-driven model of a Digital PLL used in the context of a polar modulation. This modeling has shown that the estimation method of the TDC gain has a big impact on the EVM for wideband modulation and a solution has been proposed which consists to add the modulation on the gain after calibration of the gain offset. This transforms the classical two-points modulator into a three-points modulator. This implementation has been validated for WCDMA standard.展开更多
Electrical ground looks simple on a schematic; unfortunately, the actual performance of a circuit is dictated by its layout （and by its printed-circuit-board）. When the ground node moves, system performance suffers ...Electrical ground looks simple on a schematic; unfortunately, the actual performance of a circuit is dictated by its layout （and by its printed-circuit-board）. When the ground node moves, system performance suffers and the system radiates electromagnetic interferences. But the understanding of the physics of ground noise can provide an intuitive sense for reducing the problem. Ground bounce can produce transients with amplitudes of volts; most often changing magnetic flux is the cause; in this work, the authors use a Finite-Difference Time-Domain to begin to understand such phenomena. Additionally, predicting substrate cross-talks in mixed-signal circuits has become a critical issue to preserve signal integrity in future integrated systems. Phenomena that involve parasitic signal propagation into the substrate are discussed. A simple methodology to predict the substrate cross-talk and some associated tools are presented. Finally, the authors indicate a stochastic method which could grasp both outer or inner RF （Radio-Frequency） radiations and substrate parasites.展开更多
This technical paper presents the resolution of high leakage current failures on QFN-mr （Quad-Flat No-leads Multi-Row） LF （leadframe） devices by optimizing the waterjet deflash process and eliminating the ESD （el...This technical paper presents the resolution of high leakage current failures on QFN-mr （Quad-Flat No-leads Multi-Row） LF （leadframe） devices by optimizing the waterjet deflash process and eliminating the ESD （electrostatic discharge） events. ESD damage to units can cause permanent or latent product failures which results in low final test yield, and worse, possible external customer complaints. The use of CO2 （carbon dioxide） bubbler was able to reduce the DI （deionized） water’s equivalent resistivity from 17 M？ to 0.30 M？, minimizing the tribocharging effect produced during the waterjet deflash process. Moreover, ESD events were eliminated by grounding the floating assembly equipment parts and installing appropriate ESD controls. It is of high importance to reduce or eliminate the leakage current failures to ensure the product quality, especially as the market becomes more demanding. After the optimization and implementation of the corrective and improvement actions, high leakage current occurrence was significantly reduced from baseline of 5,784 ppm to 20 ppm.展开更多
This technical paper presents a fundamental approach for design and optimization of a spiral inductor using ASITIC(analysis and simulation of spiral inductors and transformers for ICs)and SpiralCalc(integrated spiral ...This technical paper presents a fundamental approach for design and optimization of a spiral inductor using ASITIC(analysis and simulation of spiral inductors and transformers for ICs)and SpiralCalc(integrated spiral inductor calculator).Both tools are available for research and non-commercial purposes.Inductors are key components esp.for impedance matching and are designed such that they would exhibit a high Q-factor(quality-factor)for the specific inductance and frequency range of operation.A sample value of 5.3 nH is set for this paper for the spiral inductor design using the tools.For optimum Q-factor,an octagonal geometry for spiral inductor is used for ASITIC design,to have a close comparison to that of the SpiralCalc.Design methodologies for the optimization of the spiral inductor parameters such as the inductance and the Q-factor are discussed.Results comparison between the two tools is also presented.Design tradeoffs between inductor parameters are inevitable,and these parameters affect the performance of the inductor esp.at higher frequencies.With this,it is crucial that inductors be designed carefully for their effective frequency range of operation and specific requirements of the intended application.展开更多
文摘In this letter we present the results regarding the electrical and optical characterization of Geiger mode silicon avalanche photodiodes(GMAP) fabricated by silicon standard planar technology. Low dark count rates,negligible afterpulsing effects,good timing resolution and high quantum detection efficiency in all the visible range have been measured. The very good electro-optical performances of our photodiodes make them attractive for the fabrication of arrays with a large number of GMAP to be used both in the commercial and the scientific fields,as telecommunications and nuclear medical imaging.
文摘This article gives an overview of the main passive solutions and active techniques, based on AC switches to limit inrush currents in medium power AC-DC converters （up to 3.7 kW） for electric vehicle charging systems. In particular, a strategy, based on SCR （silicon controlled rectifier） phase, shift control in a mixed rectifier bridge with diodes and thyristors, is proposed. The challenge is to help designers optimize the triggering delay of SCRs to both limit the peak value of inrush current spikes and optimize the charge duration of the DC-link capacitor. A mathematical model （Mathcad engineering tool） has been defined to point out, the interest of a variable triggering delay to control SCRs to meet the expectations described previously. Experimental measurements using an industrial evaluation board of the AC-DC converter demonstrate the robustness of the method.
基金This work was supported by SMILE(a SAW-MIP Integrated device for oraL cancer Early detection)project,part of the ATTRACT program that has received funding from the European Union’s Horizon 2020 Research and Innovation Program(777222).
文摘Rapid prototyping methods for the design and fabrication of polymeric labs-on-a-chip are on the rise,as they allow high degrees of precision and flexibility.For example,a microfluidic platform may require an optimization phase in which it could be necessary to continuously modify the architecture and geometry;however,this is only possible if easy,controllable fabrication methods and low-cost materials are available.In this paper,we describe the realization process of a microfluidic tool,from the computer-aided design(CAD)to the proof-of-concept application as a capture device for circulating tumor cells(CTCs).The entire platform was realized in polymethyl methacrylate(PMMA),combining femtosecond(fs)laser and micromilling fabrication technologies.The multilayer device was assembled through a facile and low-cost solvent-assisted method.A serpentine microchannel was then directly biofunctionalized by immobilizing capture probes able to distinguish cancer from non-cancer cells without labeling.The low material costs,customizable methods,and biological application of the realized platform make it a suitable model for industrial exploitation and applications at the point of care.
基金This work has been partially supported by MIUR through the proj- ects FIRB and D.D.1105.
文摘We present the properties and potentialities of light emitting devices based on amorphous Si nanoclusters. Amorphousnanostructures may constitute an interesting alternative to Si nanocrystals for the monolithic integration of optical andelectrical functions in Si technology. In fact, they exhibit an intense room temperature electroluminescence (EL). The ELproperties of these devices have been studied as a function of current and of temperature. Moreover, to improve theextraction efficiency of the light, we have integrated the emitting system with a 2D photonic crystal structure opportunelyfabricated by using conventional optical lithography to reduce the total internal reflection of the emitted light. The extractionefficiency in such devices increases by a factor of 4 at a resonance wavelength.
文摘Cz n-type Si (100) samples with and without a top SiO2 layer were implanted with 40 keV helium ions at the same dose of 5×1016 cm-2. Cross-sectional transmission electron microscopy (XTEM) and thermal desorption spectroscopy (THDS) were used to study the thermal evolution of cavities upon and helium thermal release, respectively. XTEM results show that the presence of the top SiO2 layer could suppress the thermal growth of cavities mainly formed in the region close to the SiO2/Si interface, which leads to the reduction in both the cavity band and cavity density. THDS results reveal that the top oxide layer could act as an effective barrier for the migration of helium atoms to the surface, and it thus gives rise to the formation of more overpresurrized bubbles and to the occurrence of a third release peak located at about 1100 K. The results were qualitively discussed by considering the role of the oxide surface layer in defect migration and evolution upon annealing.
文摘We present a nonlinear event-driven model of a Digital PLL used in the context of a polar modulation. This modeling has shown that the estimation method of the TDC gain has a big impact on the EVM for wideband modulation and a solution has been proposed which consists to add the modulation on the gain after calibration of the gain offset. This transforms the classical two-points modulator into a three-points modulator. This implementation has been validated for WCDMA standard.
文摘Electrical ground looks simple on a schematic; unfortunately, the actual performance of a circuit is dictated by its layout （and by its printed-circuit-board）. When the ground node moves, system performance suffers and the system radiates electromagnetic interferences. But the understanding of the physics of ground noise can provide an intuitive sense for reducing the problem. Ground bounce can produce transients with amplitudes of volts; most often changing magnetic flux is the cause; in this work, the authors use a Finite-Difference Time-Domain to begin to understand such phenomena. Additionally, predicting substrate cross-talks in mixed-signal circuits has become a critical issue to preserve signal integrity in future integrated systems. Phenomena that involve parasitic signal propagation into the substrate are discussed. A simple methodology to predict the substrate cross-talk and some associated tools are presented. Finally, the authors indicate a stochastic method which could grasp both outer or inner RF （Radio-Frequency） radiations and substrate parasites.
文摘This technical paper presents the resolution of high leakage current failures on QFN-mr （Quad-Flat No-leads Multi-Row） LF （leadframe） devices by optimizing the waterjet deflash process and eliminating the ESD （electrostatic discharge） events. ESD damage to units can cause permanent or latent product failures which results in low final test yield, and worse, possible external customer complaints. The use of CO2 （carbon dioxide） bubbler was able to reduce the DI （deionized） water’s equivalent resistivity from 17 M？ to 0.30 M？, minimizing the tribocharging effect produced during the waterjet deflash process. Moreover, ESD events were eliminated by grounding the floating assembly equipment parts and installing appropriate ESD controls. It is of high importance to reduce or eliminate the leakage current failures to ensure the product quality, especially as the market becomes more demanding. After the optimization and implementation of the corrective and improvement actions, high leakage current occurrence was significantly reduced from baseline of 5,784 ppm to 20 ppm.
文摘This technical paper presents a fundamental approach for design and optimization of a spiral inductor using ASITIC(analysis and simulation of spiral inductors and transformers for ICs)and SpiralCalc(integrated spiral inductor calculator).Both tools are available for research and non-commercial purposes.Inductors are key components esp.for impedance matching and are designed such that they would exhibit a high Q-factor(quality-factor)for the specific inductance and frequency range of operation.A sample value of 5.3 nH is set for this paper for the spiral inductor design using the tools.For optimum Q-factor,an octagonal geometry for spiral inductor is used for ASITIC design,to have a close comparison to that of the SpiralCalc.Design methodologies for the optimization of the spiral inductor parameters such as the inductance and the Q-factor are discussed.Results comparison between the two tools is also presented.Design tradeoffs between inductor parameters are inevitable,and these parameters affect the performance of the inductor esp.at higher frequencies.With this,it is crucial that inductors be designed carefully for their effective frequency range of operation and specific requirements of the intended application.
