Bipolar Gain Research Articles

Comparative analysis of heavy ions and alpha particles impact on gate-all-around TFETs and gate-all-around MOSFETs

The single-event-transient (SET) effect due to heavy ions and alpha particles irradiation on n-type gate-all-around tunnel field effect transistor (GAA TFET) and n-type gate-all-around MOSFET (GAA MOSFET) has been carried out. Due to differences in carrier injection mechanisms, the generated electron-hole pairs (EHPs) due to high-energy particles (HEPs) act differently on the device. In addition, the impact of HEPs (i.e., heavy ions and alpha particles) on several locations along the channel are analyzed followed by the analysis of different energies of heavy ions and alpha particles irradiation on the device. Further, the impact of varying striking angles of HEPs on the device is also analyzed to get a close match as practically exposed device characteristic. Finally, the bipolar gain of the device has been analyzed which shows GAA TFET device has more immunity toward heavy ions strike and weak immunity toward alpha particle strikes when compared to the GAA MOSFET counterpart.

TCAD simulation study of heavy ion radiation effects on hetero junctionless tunnel field effect transistor

Semiconductor devices used in radiation environment are more prone to degradation in device performance. Junctionless Tunnel Field Effect Transistor (JLTFET) is one of the most potential candidates which overcomes the short channel effects and fabrication difficulties. In this work, 20 nm JLTFET is proposed with Silicon in the drain/channel region whereas source uses different materials, Silicon Germanium (SiGe), Gallium Nitride (GaN), Gallium Arsenide (GaAs), Indium Arsenide (InAs). The device performance is examined by subjecting it to heavy ion radiation at a lower and higher dose of linear energy transfer (LET) values. It can be seen that the most sensitive location is the source/channel (S/C) interface for SiGe, GaN and GaAs whereas the drain/channel (D/C) interface for InAs. Further analysis is carried out at these vulnerable regions by matching ION of all materials. The parameters, transient peak current (Ipeak), collected charge (QC), threshold voltage shift (ΔVth) and bipolar gain (β) are extracted using transient simulations. It is observed that for a lower dose of LET, Ipeak of SiGe is 27% lesser than InAs and for higher dose of LET, SiGe shows 56% lesser Ipeak than InAs. SiGe is less sensitive at lower and higher dose of LET due to reduced ΔVth, tunneling and electron density.

Radiation study of TFET and JLFET-based devices and circuits: a comprehensive review on the device structure and sensitivity

All electronic devices when used in a radiation environment undergo significant changes in their electrical properties. It is interesting to explore the effects of radiation, not only on conventional MOSFET devices but also on novel devices like FinFET, Tunneling Field Effect Transistor (TFET), and Junctionless Field Effect Transistor (JLFET). This study presents a systematic review of radiation studies on TFET and JLFET-based devices/circuits. TFET and JLFET have gained popularity in recent days due to their wide use in ultra-scaled designs than conventional CMOS. The effect of radiation on a divergent range of TFET and JLFET devices and circuits is explored. The variations in DC characteristics and electrical parameters under the influence of radiation strikes are analyzed in detail. The radiation effects like Total Ionizing Dose (TID), and Single Event Upset (SEU) are noted for these devices/circuits. The radiation study on different devices shows that these devices are sensitive to Single Event Effect (SEE), steeper Subthreshold Swing (SS), increase in Electron Hole Pair (EHP) production, increase in drain current (ID), and increase in collected charge (QC), decrease in bipolar gain and trans-conductance.

A Single-Phase Compact-Sized Matrix Converter with Symmetrical Bipolar Buck and Boost Output Voltage Control

The development of single-phase symmetrical bipolar voltage gain matrix converters (MC) is growing rapidly as they find their application in power systems for dynamic restoration of line voltages, high voltage AC–DC converters, and variable frequency controllers for many industrial processes. However, the existing trend in matrix converter technology is a buck–boost operation that has inherently serious issues of high voltage and current surges or stresses. This is a big source of the high voltage and current rating of semiconductor switching devices. There is also a problem of high ripples both for voltage as well for current, requiring large size of filtering capacitors and inductors. The non-symmetrical control of the voltage gain increases the control complication. A large count of operating transistors is critical regarding their cost, size, and power conversion losses, as the space and cost required by their gate control circuits are much larger than the size and cost of the switching transistors. Thus, in this research work, a new single-phase MC is introduced only employing six fully controlled switching devices, ensuring similar operation or outputs as is obtained from the existing topologies that require the use of eight or more fully controlled switching devices, and the reduction by two or more switching transistors helps to compact the overall size and lower the overall cost. The separation in its voltage buck and boost operation enables smooth control of the voltage gain through duty cycle control. The low values of the voltage and current surges reduce the power rating and losses of the switching devices. The flow of the current in the filtering inductor is kept unidirectional to avoid the current interruption and reversal problem once the operation of the converter is abruptly switched from inverting to non-inverting and vice versa. All these factors are comprehensively detailed through the circuit’s description and comparative analysis. Simulation and practical results are presented to confirm the effectiveness of the developed circuit topology.

3.101 Does Lithium With Antipsychotics Make Children and Adolescents With Bipolar Disorder Gain Weight?

Bipolar disorder in children and adolescents is a serious illness with a chronic course and a high recurrence rate. Drug compliance issues are very important to maintain therapy. Most antipsychotics and mood stabilizers cause weight gain and lead to poor drug compliance. Mood stabilizers and antipsychotics are usually used for treating bipolar disorder. However, weight gain is an adverse effect of these drugs. In this study, we tried to investigate whether lithium with antipsychotics causes more weight gain than lithium monotherapy and to determine which mood stabilizer causes more weight gain.

Investigation of Single-Event-Transient Effects Induced by Heavy-Ion in All-Silicon DG-TFET

The heavy-ion analysis is a single-event-effect (SEE) that produces a single-event-transient (SET) pulse of current. In this work, the analysis was done to observe the maximum impact of heavy-ions on a calibrated double-gate tunnel field-effect transistor (DG-TFET) taken as a device under test (DUT). The impact of heavy-ions on DG-TFET is compared with the previous work done for different TFETs. The ions are directed to strike vertically at five different positions; source, source-body junction, body, drain-body junction, and the drain region of DG-TFET. The analysis is done by observing the heavy-ion generation rate, heavy-ion charge density, and transient current for the strike of the ion at different locations on the DUT and at different linear energy transfer (LET) values with the help of physics-based numerical simulation. In the study, a detailed analysis of the transient current due to a heavy-ion strike in the body region is reported, and this transient current is compared with the existing reported data for different FETs. Bipolar gain of the device is also observed for a heavy-ion strike in the body region, which is an important parameter for analyzing SEE. The findings in this study can give a new insight into SEE in TFET devices and can also provide guidelines for radiation-hardened applications for TFET-based circuits.

A Bipolar Voltage Gain Boost AC-AC Converter Based on Four Switching Transistors

In numerous applications, such as the correction of grid voltage during voltage sag or swell events caused by system faults, it is necessary to ensure the stabilization of the output voltage with in-phase and out-phase features. This feature can also be employed in high-voltage-gain AC to DC conversion. AC voltage control schemes with one-stage conversion are viable approaches in this regard as only voltage regulation is needed. This conversion approach has strong potential for such applications as it is simple to realize. The voltage-correcting compensators are connected in series with the lines. The inputs of the AC voltage controllers employed in the voltage-correcting compensators may be connected to the faulty phase or other healthy phases. The number of AC voltage controllers used in a voltage compensator are one and two if its input power is drawn from the faulty and non-faulty phases, respectively. In the latter case, voltage gains and phase adjustment are major problems. There is no such issue in the first approach, where the voltage-correcting controller is connected to the line where the voltage variation is to be corrected. A high voltage gain more than the unity of both voltage polarities is required if the depth level of the correcting voltage is around 50% or more. The size and cost of a voltage-correcting controller depend on the number of switching transistors, as an isolated DC source with a gate-controlling circuit is a mandatory requirement for the switching operation of each transistor. Therefore, in the suggested research, an AC voltage controller having bipolar voltage gain is realized only with four switching transistors and six diodes, which reduces the overall size and cost significantly. The verification of the suggested topology is ensured by obtaining the simulation and real results from Simulink-based and practical-based platforms, respectively.

Influence of ionisation track structure on 20 nm FDSOI transistor

The response of a 20-nm fully depleted silicon on insulator (FDSOI) transistor under irradiation by heavy ions is analysed using GEometry ANd Tracking (Geant4) and Synopsys Sentaurus device simulations. Because of the huge energy fluctuations between thin silicon layers, the deposited energy calculated using surface linear energy transfer (LET) is imprecise under the incidence of heavy ions at very low energy (< 0.3 MeV/amu). The radial ionisation distribution range obtained by Geant4 decreases with an increase in ion mass at the same silicon depth (2 μm). Using radial ionisation distribution data in the electrical step of simulating a single event, the current peak value under irradiation by low-energy Xe ions is the highest value (229.6 μA), which reveals that low-kinetic-energy ions may cause damage larger than that caused by the incidence of high-kinetic-energy ions. Additionally, although the high-energy ions generate larger collected charges in the device, the larger deposited charges will minimise the resulting parasitic bipolar amplification gain.

Dual Output and High Voltage Gain DC-DC Converter for PV and Fuel Cell Generators Connected to DC Bipolar Microgrids

This paper introduces a new topology for a DC-DC converter with bipolar output and high voltage gain. The topology was designed with the aim to use only one active power switch. Besides the bipolar multiport output and high voltage gain this converter has another important feature, namely, it has a continuous input current. Due to the self-balancing bipolar outputs, the proposed topology is suitable for bipolar DC microgrids. Indeed, the topology balancing capability can achieve the two symmetrical voltage poles of bipolar DC microgrids. Furthermore, it is possible to create a midpoint in the output of the converter that can be directly connected to the ground of the DC power supply, avoiding common-mode leakage currents in critical applications such as transformerless grid-connect PV systems. The operating principle of the proposed topology will be supported by mathematical analysis. To validate and verify the characteristics of the presented topology, several experimental results are shown.

High-Efficiency Single-Phase Matrix Converter With Diverse Symmetric Bipolar Buck and Boost Operations

Single-phase matrix converters (MCs) are undergoing rapid developments due to their bipolar voltage gain (as required in dynamic voltage restorers) and step-changed frequency operation (used in high step-up ac-dc rectifiers, and to provide medium frequency isolation in traction and wind turbine converters, etc.). However, existing buck-boost MCs require high-voltage/current rating devices, and suffer from large component voltage/current stresses and ripples, significantly degrading their efficiency. This article proposes a highly efficient single-phase buck-boost MC; consisting of eight IGBTs (implemented using two full-bridge IGBT modules), second-order input and output filters, and a small value film capacitor. Efficient discrete inverting and noninverting buck and boost operations are proposed (same as that of sixteen-switch cascaded buck-boost MC) with significantly lower component voltage/current stresses and ripples. In addition, flexible inverting and noninverting buck-boost operations are proposed with independent control of buck and boost duty ratios. All of the proposed operations are free of commutation issues, compatible with reactive loads, and provide smooth input and output currents. Furthermore, all the switches have same voltage stresses, and all four switches in a full-bridge module experience the same current stresses. A comprehensive description of circuit operation is presented based on a number of proposed switch modulation strategies with a nonunity power factor load, followed by design guidelines, and comparative evaluations with existing topologies. Finally, experimental verification results are presented, using a 400-VA laboratory prototype converter.

A High-Frequency Isolated Multilevel Cascaded-Type Bipolar Direct PWM AC–AC Converter for Utility Voltage Compensation

A high-frequency isolated multilevel cascaded-type bipolar direct PWM ac-ac converter is proposed. By cascading N-unit cells, the converter can produce symmetric bipolar voltage gain of ±ND. It does not require a separate ac source for each unit cell, and can provide higher ac output voltages with multiple levels using low-voltage rating devices, decreasing output voltage harmonics and filtering requirements. Moreover, phase-shift PWM switching is employed, increasing the effective frequency of the output filter, further reducing its requirements. The converter can be utilized as a dynamic voltage restorer (DVR) for grid voltage regulation, with the following features: No need for an external dc source, separate ac sources, and a line-frequency voltage injection transformer. Injection of higher voltage magnitudes than the line voltage, mitigating deep voltage sags. Injection of a negative series voltage to provide compensation for voltage swells. The detailed circuit operation is explained together with component design guidelines and application as DVR. Finally, experimental results are provided using an 800-W scale-down laboratory prototype.

A New Single-Phase AC Voltage Converter With Voltage Buck Characteristics for Grid Voltage Compensation

Voltage sags and swells are the major problems of the power distribution system that arise due to uneven distribution of the single-phase and nonlinear loads. They severely degrade the power quality and may cause the failure of the equipment at the user's side. The voltage sag and swell issues are compensated by operating the AC voltage controllers with bipolar voltage gain characteristics. In these converters, high switching voltage and current, and a large number of switching devices are the main issues that cause unwanted power losses and result in reduced efficiency of the system. High voltage stresses may cause device failure due to the increase in dv/dt rating. The large count of switching devices results in high cost and high conversion losses. So here, we propose a novel AC converter with fewer switching devices that reduces switching voltage and current to have low conversion losses. The amplitude of the output is governed through the direct PWM control (DPWM) of one switch that controls the switching state of the other switch indirectly called indirect PWM control switch (IDPWM). The detailed analysis of the proposed converter is carried out to compare its performance with the existing converters. MATLAB/Simulink environment-based simulation results are proved through the experimental results obtained by developing a hardware prototype.

Modeling of IGBT With High Bipolar Gain for Mitigating Gate Voltage Oscillations During Short Circuit

In this paper, the impact of the p-n-p bipolar transistor gain on the short-circuit behavior of high-voltage trench insulated-gate bipolar transistors (IGBTs) is analyzed. The short-circuit ruggedness against high-frequency oscillations is strongly improved by increasing the hole current supplied by the collector. By doing so, the electric field at the emitter of the IGBT is increased and less influenced by the amount of the excess charge (i.e., the electric field is fixed). The charge-field interactions during the short circuit event, leading to periodic charge storage and charge removal effect and provoking miller capacitance variations, can be mitigated. The effectiveness of using IGBTs with a high bipolar gain is validated through both simulations and experiments, also a design rule to tradeoff the IGBT’s losses and short-circuit robustness is provided.

Analysis of bipolar amplification due to heavy-ion irradiation in 45 nm FDSOI MOSFET with thin BOX and ground plane

Single event transient (SET) due to heavy-ion strike is one of the serious reliability issues when the MOSFET is scaled down to advanced technology nodes. SOI technology is more immune to SET than bulk technology due to its smaller collection volume and buried oxide (BOX). The device structure modification using thin BOX and ground plane (GP) doping will aid further scaling of SOI MOSFET. In this paper, the bipolar amplification due to heavy-ion strike is analysed for both thick BOX device and thin BOX device with GP in 45 nm SOI technology. The bipolar gain is reduced by optimizing GP doping. The effect of substrate bias and supply voltage scaling on the bipolar gain is also analysed. The replacement of thick BOX with thin BOX (without GP) reduces the bipolar gain by 3.2 times for LET = 0.2 MeV/(mg/cm2). The inclusion of a GP layer underneath the thin BOX reduces the bipolar gain further by 2.3 times. This lower bipolar amplification of thin BOX with GP device makes it to be less sensitive to the heavy-ion strike than the one with thick BOX.

Excess OFF-State Current in InGaAs FinFETs: Physics of the Parasitic Bipolar Effect

InGaAs FinFETs are challenged by relatively high leakage current in the OFF state. This originates from band-to-band tunneling (BTBT) at the drain end of the channel that is amplified by a parasitic bipolar effect (PBE) as a result of its floating body. In this paper, we present a simple model of the PBE in InGaAs FinFETs, which captures the key gate length and fin width dependences. Our model accounts for surface recombination at the sidewalls of the fin as well as bulk recombination at the heavily doped source. When compared with experimental results, our model suggests that fin sidewall recombination dominates in long gate length transistors and leads to an exponential gate length dependence of the current gain on the parasitic bipolar junction transistor (BJT). The model enables the extraction of the carrier diffusion length which exhibits the predicted fin width dependence. For short gate length transistors, source recombination is shown to dominate and the parasitic bipolar gain scales with the inverse of the gate length.

A Single-Phase Buck and Boost AC-to-AC Converter with Bipolar Voltage Gain: Analysis, Design, and Implementation

In this research, a new single-phase direct AC-to-AC converter, operating in buck and boost mode, with a bipolar voltage gain, is proposed. The operation is accomplished through high frequency direct and indirect PWM control of a single switch with low voltage stresses. This reduces, not only the control effort, but also the switching losses. The low voltage stresses across the high frequency switches, reduce the dv/dt problem significantly without any loss and bulky voltage snubber arrangement. The operation, in its all-operating modes, has a low inductor ripple current and switching current. The proposed converter may be employed as an AC voltage restorer in a power distribution system to cope with the voltage sag and swell issues. The detailed analysis of the proposed converter is carried out in order to compare its performance with the existing converters. The simulation results obtained using the MATLAB/Simulink environment are verified through experimental results.

A Scaling Study of Excess OFF-State Current in InGaAs Quantum-Well MOSFETs

A scaling study of excess OFF-state current in planar InGaAs quantum-well MOSFETs is reported. We find that pure band-to-band tunneling (BTBT) dominates the drain OFF-state current in deviceswith channel length above $\sim 1~\mu \text{m}$ . In this regime, the drain–gate voltage sets the rate of BTBT. In devices with channel lengths below $\textsf {1}~\mu \text{m}$ , a parasitic bipolar transistor effect becomes relevant. The bipolar current gain is found to scale inversely with the effective channel length for Lg between 70 nm and $\textsf {1}~\mu \text{m}$ , as expected from simple bipolar transistor theory. For Lg below ~7 nm, the OFF-state current increases rapidly due to an enhancement in bipolar current gain as a result of strong short-channel effects and punchthrough. Current gains in excess of 104 have been observed. A reduction in channel thickness decreases both BTBT and the bipolar gain effect.

Multiscale Modeling of Total Ionizing Dose Effects in Commercial-off-the-Shelf Parts in Bipolar Technologies

A multiscale modeling platform that supports the “virtual” qualification of commercial-off-the-shelf parts is presented. The multiscale approach is divided into two modules. The first module generates information related to the bipolar junction transistor gain degradation that is a function of fabrication process, operational, and environmental inputs. The second uses this information as inputs for radiation-enabled circuit simulations. The prototype platform described in this paper estimates the total ionizing dose and dose rate responses of linear bipolar integrated circuits for different families of components. The simulation and experimental results show good correlation and suggest this platform to be a complementary tool within the radiation-hardness assurance flow. The platform may reduce some of the costly reliance on testing for all systems.

Dual-Buck AC–AC Converter With Inverting and Non-Inverting Operations

In this paper, a novel buck–boost ac–ac converter is proposed. The basic switching unit of the proposed converter is a unidirectional buck circuit; therefore, it has no shoot-through worries. It can achieve safe commutation without using RC snubbers or soft commutation strategies. It can be implemented with power MOSFETs without their body diodes conducting and, for current freewheeling external diodes, can be used to minimize the reverse recovery issues and related loss. It has a bipolar voltage gain with both inverting and non-inverting operations. The non-inverting operation can be used to compensate voltage sag, and inverting operation can be used to compensate voltage swell. Therefore, the proposed converter as a dynamic voltage restorer is capable of compensating for both voltage sag and swell in a wide range. The detailed theoretical analysis followed by detailed experimental results of a 300-W prototype converter is provided.

Transformer‐less dynamic voltage restorer based on a three‐leg ac/ac converter

A transformer-less dynamic voltage restorer (DVR) with bipolar voltage gain capability is proposed in this study. The DVR is formed by a three-leg ac/ac converter with its output capacitor in series with the transmission line. Since the energy used for voltage compensation is obtained from the grid, long-time voltage disturbances can be compensated without using bulky energy storage elements. As a result, the proposed DVR has the features of compact structure, light weight, and low cost. Moreover, it also has a high reliability as the commutation problem is avoided by adopting the proposed modulation strategy. A detailed analysis of the topology structure and operation principle is given, followed by the developed control method. Finally, simulations and experimental results are presented to verify the validity of the DVR.