The possible issues related to the use of last-generations Insulated Gate Bipolar Transistors (IG... more The possible issues related to the use of last-generations Insulated Gate Bipolar Transistors (IGBTs) switches into a Marx-topology klystron modulator are discussed. Experimental results obtained from two cells Marx prototypes using two different solutions, including single device and series connected devices both hard-switched, are presented. The use of single high voltage device per cell allowed us to obtain lower on-state voltage drop but much slower switching times. On the other side the series connection of lower voltage IGBTs results in much faster commutations and lower devices costs accompanied by a larger on state voltage drop.
2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe), 2020
In this paper we present the operation principle of a Metal Oxide Vacuum Field Effect Transistor ... more In this paper we present the operation principle of a Metal Oxide Vacuum Field Effect Transistor (MOVFET). The idea is to exploit a technology proposed in the literature to realize nano devices with low threshold voltage for power applications. The principle of operation of the MOVFET is based on the emission of electrons from a cold cathode in a vacuum in such a way to obtain a pentode-like characteristics with a very low on resistance. This last feature is particularly interesting for the application as switches in power electronics applications. Moreover, the absence of a gate oxide which is always present in traditional MOSFETs suggests that this device can have better reliability features even in rad hard applications. A numerical simulator is used to evaluate the impact of the technological parameters on the static characteristics of the device and the perspective performances in power electronics applications.
The decision to use a commercial power MOSFET in a harsh radioactive environment[1], such as oute... more The decision to use a commercial power MOSFET in a harsh radioactive environment[1], such as outer space, is subordinated to the capacity of the device to tolerate single event effects (SEE)[2] caused by single ionising particles. An incident ion may trigger charge generating mechanisms in the active volumes of the device that may give rise to a simple momentary malfunction or to a destructive event. We propose an original statistical characterization of two different charge generation mechanisms based on experimentally measured drain current pulses obtained in various operational conditions (different ion species and different bias voltages). In a power MOSFET, single event effect failure modes include both single event burnout (SEB) and single event gate rupture (SEGR)[3]. The occurrence of a destructive SEB is related to the activation of the parasitic transistor of the structure. The activation is due to the interaction of the ionisation space charge, produced by the energetic i...
The Fifth International Conference on Power Electronics and Drive Systems, 2003. PEDS 2003.
ABSTRACT An experimental investigation about the behaviour of 3300 V - 1200 A IGBT modules both a... more ABSTRACT An experimental investigation about the behaviour of 3300 V - 1200 A IGBT modules both at high temperature and for large output currents is presented. The real IGBT turn-off limits, in terms of maximum switchable current, and the short circuit behaviour at larger different environmental temperatures are identified. The experimental study has been performed by means of a nondestructive set-up where IGBT modules are switched on an inductive load in presence of a protection circuit. It is activated at the occurrence of dangerous operating conditions, thus preventing the IGBT module failure. On the basis of an extensive experimental characterization, the paper demonstrates the possibility of operating up to 145 °C case temperature and at currents much larger than the declared RBSOA limits.
European Conference on Radiation and its Effects on Components and Systems, 2003
In this paper we present an experimental study of the effect of the epi-layer parameters on the r... more In this paper we present an experimental study of the effect of the epi-layer parameters on the reliability of medium voltage power VDMOSFET to sustain single event effects caused by the impact of heavy ions. The impact of energetic particles is accompanied by a charge generation that we experimentally detected and can cause the premature failure of the device. The
The aim of this paper is to present the performances of the fully integrated MOS-Gated GTO: a new... more The aim of this paper is to present the performances of the fully integrated MOS-Gated GTO: a new power device well suited to be applied in the field of high blocking voltages. We start from the characteristics of a fabricated 1.2kV device used to tune the simulator, and we extend the analysis up to 4.5kV blocking voltage. Simulation results are used to understand in detail the physical operations of the device at high values of the blocking voltage and how they compare to the homologous IGBTs. The effects of the lifetime variation are also presented and the trade-off between static and dynamic performances are discussed in detail.
The behaviour in terms of robustness of series-connected high power IGBT modules is presented, ar... more The behaviour in terms of robustness of series-connected high power IGBT modules is presented, arranged in a topology which ensures voltage balance on IGBT’s and diodes by means of a simple auxiliary circuit applied directly on the high power devices, which are used in hard switching mode. Analyses in terms of IGBT and diode SOA (safe operating area), collector to
In this paper we propose an experimental study, supported by numerical simulation, of the role of... more In this paper we propose an experimental study, supported by numerical simulation, of the role of the parasitic transistor on the charge generation phenomenon observed during the impact of heavy ions on medium voltage power MOSFET. The amount of the generated charge is reliant on the gain of the BJT which decreases with an increase of the epitaxial layer thickness in high injection levels and low fields. The charge amplification can induce a premature damage of the device under test and then radically reduces its reliability to sustaining single event effects.
A new test methodology for the analysis of SEE in power MOSFET is presented. It is based on the c... more A new test methodology for the analysis of SEE in power MOSFET is presented. It is based on the combined use of an Ion Electron Emission Microscope (IEEM) and an experimental set-up which is able to acquire the drain signals associated to the impacts during the irradiation. The charge generation sensitivity map of a 200V power MOSFET has been measured.
ABSTRACT Starting from a physical model of the electric field that develops in the gate oxide dur... more ABSTRACT Starting from a physical model of the electric field that develops in the gate oxide during heavy-ion irradiation, we have experimentally and numerically investigated the single event gate damage observed in medium voltage power MOSFETs. Simulation results reveal that the total electric field reached during the heavy-ion impact is close to the one that is known to trigger the formation of latent damages during electro-static discharge (ESD) experiments.
Abstract The objective of the paper is to present a trap assisted conduction mechanism able to ex... more Abstract The objective of the paper is to present a trap assisted conduction mechanism able to explain the creation of a conductive path in the gate oxide of SiC power MOSFET during the impact of heavy ions. The consequent large current flow through the oxide can induce damages to the gate structure. The proposed mechanism combines a Fowler-Nordheim tunneling at the SiC/SiO2 interface with a trap-assisted valence band conduction mechanisms based on Poole-Frenkel effect. The model is based on the results of 2D finite element simulation and is supported by previous works dealing with trap assisted tunneling hole injection in silicon dioxide.
Astroparticle, Particle and Space Physics, Detectors and Medical Physics Applications, 2010
The present study faces the radiation tolerance aspect for two main device categories typically u... more The present study faces the radiation tolerance aspect for two main device categories typically used for power supplies of electromagnetic calorimeters for high-energy physics, like ATLAS Liquid-Ar calorimeters: 200V-MOSFETs and 30V-MOSFETs, which are fundamental for manipulating the primary voltage and the secondary voltage, respectively, of the power distribution system. Results demonstrate that the gate driving policy can significantly affect the radiation tolerance of such devices, suggesting a promising method to reach the 1Mrad target.
This paper investigates the use of switching converters for the power supply distribution to calo... more This paper investigates the use of switching converters for the power supply distribution to calorimeters in the ATLAS experiment when the Large Hadron Collider (LHC) will be upgraded beyond the nominal luminosity. Due to the highly hostile environment the converters must operate in, all the main aspects are considered in the investigation, from the selection of the switching converter topologies
The possible issues related to the use of last-generations Insulated Gate Bipolar Transistors (IG... more The possible issues related to the use of last-generations Insulated Gate Bipolar Transistors (IGBTs) switches into a Marx-topology klystron modulator are discussed. Experimental results obtained from two cells Marx prototypes using two different solutions, including single device and series connected devices both hard-switched, are presented. The use of single high voltage device per cell allowed us to obtain lower on-state voltage drop but much slower switching times. On the other side the series connection of lower voltage IGBTs results in much faster commutations and lower devices costs accompanied by a larger on state voltage drop.
2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe), 2020
In this paper we present the operation principle of a Metal Oxide Vacuum Field Effect Transistor ... more In this paper we present the operation principle of a Metal Oxide Vacuum Field Effect Transistor (MOVFET). The idea is to exploit a technology proposed in the literature to realize nano devices with low threshold voltage for power applications. The principle of operation of the MOVFET is based on the emission of electrons from a cold cathode in a vacuum in such a way to obtain a pentode-like characteristics with a very low on resistance. This last feature is particularly interesting for the application as switches in power electronics applications. Moreover, the absence of a gate oxide which is always present in traditional MOSFETs suggests that this device can have better reliability features even in rad hard applications. A numerical simulator is used to evaluate the impact of the technological parameters on the static characteristics of the device and the perspective performances in power electronics applications.
The decision to use a commercial power MOSFET in a harsh radioactive environment[1], such as oute... more The decision to use a commercial power MOSFET in a harsh radioactive environment[1], such as outer space, is subordinated to the capacity of the device to tolerate single event effects (SEE)[2] caused by single ionising particles. An incident ion may trigger charge generating mechanisms in the active volumes of the device that may give rise to a simple momentary malfunction or to a destructive event. We propose an original statistical characterization of two different charge generation mechanisms based on experimentally measured drain current pulses obtained in various operational conditions (different ion species and different bias voltages). In a power MOSFET, single event effect failure modes include both single event burnout (SEB) and single event gate rupture (SEGR)[3]. The occurrence of a destructive SEB is related to the activation of the parasitic transistor of the structure. The activation is due to the interaction of the ionisation space charge, produced by the energetic i...
The Fifth International Conference on Power Electronics and Drive Systems, 2003. PEDS 2003.
ABSTRACT An experimental investigation about the behaviour of 3300 V - 1200 A IGBT modules both a... more ABSTRACT An experimental investigation about the behaviour of 3300 V - 1200 A IGBT modules both at high temperature and for large output currents is presented. The real IGBT turn-off limits, in terms of maximum switchable current, and the short circuit behaviour at larger different environmental temperatures are identified. The experimental study has been performed by means of a nondestructive set-up where IGBT modules are switched on an inductive load in presence of a protection circuit. It is activated at the occurrence of dangerous operating conditions, thus preventing the IGBT module failure. On the basis of an extensive experimental characterization, the paper demonstrates the possibility of operating up to 145 °C case temperature and at currents much larger than the declared RBSOA limits.
European Conference on Radiation and its Effects on Components and Systems, 2003
In this paper we present an experimental study of the effect of the epi-layer parameters on the r... more In this paper we present an experimental study of the effect of the epi-layer parameters on the reliability of medium voltage power VDMOSFET to sustain single event effects caused by the impact of heavy ions. The impact of energetic particles is accompanied by a charge generation that we experimentally detected and can cause the premature failure of the device. The
The aim of this paper is to present the performances of the fully integrated MOS-Gated GTO: a new... more The aim of this paper is to present the performances of the fully integrated MOS-Gated GTO: a new power device well suited to be applied in the field of high blocking voltages. We start from the characteristics of a fabricated 1.2kV device used to tune the simulator, and we extend the analysis up to 4.5kV blocking voltage. Simulation results are used to understand in detail the physical operations of the device at high values of the blocking voltage and how they compare to the homologous IGBTs. The effects of the lifetime variation are also presented and the trade-off between static and dynamic performances are discussed in detail.
The behaviour in terms of robustness of series-connected high power IGBT modules is presented, ar... more The behaviour in terms of robustness of series-connected high power IGBT modules is presented, arranged in a topology which ensures voltage balance on IGBT’s and diodes by means of a simple auxiliary circuit applied directly on the high power devices, which are used in hard switching mode. Analyses in terms of IGBT and diode SOA (safe operating area), collector to
In this paper we propose an experimental study, supported by numerical simulation, of the role of... more In this paper we propose an experimental study, supported by numerical simulation, of the role of the parasitic transistor on the charge generation phenomenon observed during the impact of heavy ions on medium voltage power MOSFET. The amount of the generated charge is reliant on the gain of the BJT which decreases with an increase of the epitaxial layer thickness in high injection levels and low fields. The charge amplification can induce a premature damage of the device under test and then radically reduces its reliability to sustaining single event effects.
A new test methodology for the analysis of SEE in power MOSFET is presented. It is based on the c... more A new test methodology for the analysis of SEE in power MOSFET is presented. It is based on the combined use of an Ion Electron Emission Microscope (IEEM) and an experimental set-up which is able to acquire the drain signals associated to the impacts during the irradiation. The charge generation sensitivity map of a 200V power MOSFET has been measured.
ABSTRACT Starting from a physical model of the electric field that develops in the gate oxide dur... more ABSTRACT Starting from a physical model of the electric field that develops in the gate oxide during heavy-ion irradiation, we have experimentally and numerically investigated the single event gate damage observed in medium voltage power MOSFETs. Simulation results reveal that the total electric field reached during the heavy-ion impact is close to the one that is known to trigger the formation of latent damages during electro-static discharge (ESD) experiments.
Abstract The objective of the paper is to present a trap assisted conduction mechanism able to ex... more Abstract The objective of the paper is to present a trap assisted conduction mechanism able to explain the creation of a conductive path in the gate oxide of SiC power MOSFET during the impact of heavy ions. The consequent large current flow through the oxide can induce damages to the gate structure. The proposed mechanism combines a Fowler-Nordheim tunneling at the SiC/SiO2 interface with a trap-assisted valence band conduction mechanisms based on Poole-Frenkel effect. The model is based on the results of 2D finite element simulation and is supported by previous works dealing with trap assisted tunneling hole injection in silicon dioxide.
Astroparticle, Particle and Space Physics, Detectors and Medical Physics Applications, 2010
The present study faces the radiation tolerance aspect for two main device categories typically u... more The present study faces the radiation tolerance aspect for two main device categories typically used for power supplies of electromagnetic calorimeters for high-energy physics, like ATLAS Liquid-Ar calorimeters: 200V-MOSFETs and 30V-MOSFETs, which are fundamental for manipulating the primary voltage and the secondary voltage, respectively, of the power distribution system. Results demonstrate that the gate driving policy can significantly affect the radiation tolerance of such devices, suggesting a promising method to reach the 1Mrad target.
This paper investigates the use of switching converters for the power supply distribution to calo... more This paper investigates the use of switching converters for the power supply distribution to calorimeters in the ATLAS experiment when the Large Hadron Collider (LHC) will be upgraded beyond the nominal luminosity. Due to the highly hostile environment the converters must operate in, all the main aspects are considered in the investigation, from the selection of the switching converter topologies
Uploads
Papers by G. Busatto