Mechanism of single-event transient pulse quenching between dummy gate isolated logic nodes

As integrated circuits scale down in size, a single high-energy ion strike often affects multiple adjacent logic nodes.The so-called single-event transient（SET） pulse quenching induced by single-event charge sharing collection has been widely studied. In this paper, SET pulse quenching enhancement is found in dummy gate isolated adjacent logic nodes compared with that isolated by the common shallow trench isolation（STI）. The physical mechanism is studied in depth and this isolation technique is explored for SET mitigation in combinational standard cells. Three-dimensional（3D） technology computer-aided design simulation（TCAD） results show that this technique can achieve efficient SET mitigation.

A single-event transient induced by a pulsed laser in a silicon-germanium heterojunction bipolar transistor

A study on the single event transient （SET） induced by a pulsed laser in a silicon-germanium （SiGe） heterojunction bipolar transistor （HBT） is presented in this work. The impacts of laser energy and collector load resistance on the SET are investigated in detail. The waveform, amplitude, and width of the SET pulse as well as collected charge are used to characterize the SET response. The experimental results are discussed in detail and it is demonstrated that the laser energy and load resistance significantly affect the SET in the SiGe HBT. Furthermore, the underlying physical mechanisms are analyzed and investigated, and a near-ideal exponential model is proposed for the first time to describe the discharge of laser-induced electrons via collector resistance to collector supply when both base-collector and collector-substrate junctions are reverse biased or weakly forward biased. Besides, it is found that an additional multi-path discharge would play an important role in the SET once the base-collector and collector-substrate junctions get strongly forward biased due to a strong transient step charge by the laser pulse.

Temperature dependence of single-event transients in SiGe heterojunction bipolar transistors for cryogenic applications

We experimentally demonstrate that the dominant mechanism of single-event transients in silicon-germanium heterojunction bipolar transistors(SiGe HBTs)can change with decreasing temperature from+20℃to-180℃.This is accomplished by using a new well-designed cryogenic experimental system suitable for a pulsed-laser platform.Firstly,when the temperature drops from+20℃to-140℃,the increased carrier mobility drives a slight increase in transient amplitude.However,as the temperature decreases further below-140℃,the carrier freeze-out brings about an inflection point,which means the transient amplitude will decrease at cryogenic temperatures.To better understand this result,we analytically calculate the ionization rates of various dopants at different temperatures based on Altermatt's new incomplete ionization model.The parasitic resistivities with temperature on the charge-collection pathway are extracted by a two-dimensional(2D)TCAD process simulation.In addition,we investigate the impact of temperature on the novel electron-injection process from emitter to base under different bias conditions.The increase of the emitter-base junction's barrier height at low temperatures could suppress this electron-injection phenomenon.We have also optimized the built-in voltage equations of a high current compact model(HICUM)by introducing the impact of incomplete ionization.The present results and methods could provide a new reference for effective evaluation of single-event effects in bipolar transistors and circuits at cryogenic temperatures,and could provide a new evidence of the potential of SiGe technology in applications in extreme cryogenic environments.

Experimental and simulation studies of single-event transient in partially depleted SOI MOSFET

In this study, we investigate the single-event transient（SET） characteristics of a partially depleted silicon-on-insulator（PDSOI） metal-oxide-semiconductor（MOS） device induced by a pulsed laser.We measure and analyze the drain transient current at the wafer level. The results indicate that the body-drain junction and its vicinity are more SET sensitive than the other regions in PD-SOI devices.We use ISE 3D simulation tools to analyze the SET response when different regions of the device are hit. Then, we discuss in detail the characteristics of transient currents and the electrostatic potential distribution change in devices after irradiation. Finally, we analyze the parasitic bipolar junction transistor（p-BJT） effect by performing both a laser test and simulations.

Analysis of single-event transient sensitivity in fully depleted silicon-on-insulator MOSFETs

Based on 3 D-TCAD simulations, single-event transient(SET) effects and charge collection mechanisms in fully depleted silicon-on-insulator(FDSOI) transistors are investigated. This work presents a comparison between28-nm technology and 0.2-lm technology to analyze the impact of strike location on SET sensitivity in FDSOI devices. Simulation results show that the most SET-sensitive region in FDSOI transistors is the drain region near the gate. An in-depth analysis shows that the bipolar amplification effect in FDSOI devices is dependent on the strike locations. In addition, when the drain contact is moved toward the drain direction, the most sensitive region drifts toward the drain and collects more charge. This provides theoretical guidance for SET hardening.

Analytical solutions of transient pulsed eddy current problem due to elliptical electromagnetic concentrative coils

The electromagnetic concentrative coils are indispensable in the functional magnetic stimulation and have potential applications in nondestructive testing. In this paper, we propose a figure-8-shaped coil being composed of two arbitrary oblique elliptical coils, which can change the electromagnetic concentrative region and the magnitude of eddy current density by changing the elliptical shape and/or spread angle between two elliptical coils. Pulsed current is usually the excitation source in the functional magnetic stimulation, so in this paper we derive the analytical solutions of transient pulsed eddy current field in the time domain due to the elliptical concentrative coil placed in an arbitrary position over a half-infinite plane conductor by making use of the scale-transformation, the Laplace transform and the Fourier transform are used in our derivation. Calculation results of field distributions produced by the figure-8-shaped elliptical coil show some behaviours as follows： 1） the eddy currents are focused on the conductor under the geometric symmetric centre of figure-8-shaped coil; 2） the greater the scale factor of ellipse is, the higher the eddy current density is and the wider the concentrative area of eddy current along y axis is; 3） the maximum magnitude of eddy current density increases with the increase of spread angle. When spread angle is 180°, there are two additional reverse concentrative areas on both sides of x axis.

Simplified Calculation Method for Transient Field of Transverse Electromagnetic Horn Antenna Used by High-altitude Electromagnetic Pulse Simulator

For conveniently calculating the radiated electric field of transverse electromagnetic(TEM) horn antenna,an approximate simplified analytical calculation method is suggested.This method divides the horn to a system of V-antennas and superimposes the fields of all V-antennas to obtain the field of the TEM horn.The method is compared with the traditional analytical method and numerical method.The obtained results suggest that the proposed method is valid,simple and that it can fastly calculate the radiated electric field of the TEM horn antenna in an arbitrary space with an arbitrary excitation voltage.Based on this method,radiation of the TEM horn antenna of a high-altitude electromagnetic pulse(HEMP) simulator is simulated.Rise time,pulse width,peak value of electric field,and field distribution are analyzed.Results show that the TEM horn antenna can be used in HEMP simulators: the near field waveform is closer to the standard waveform than to the far field waveform; the standards for the rise time and the peak value of electric field are easily satisfied; the pulse width of the radiated field can be increased by broadening the pulse width of an excitation source and by making the antenna of a proper

APPLICATION OF TRANSIENT ELECTROMAGNETIC PULSE IN DETECTING SUBSURFACE TARGETS

A basic scheme for detecting subsurface targets with nanosecond EM pulse and anespecially developed high quality travelling-wave antenna are described.The antenna is a sortof sector antenna with structure of three layers,which possesses higher radiation efficiency andbetter travelling-wave properties.A fine resolution graphic system and a high speed display areemployed in terminal processing.Metal pipes buried about 1 m under the earth can be detectedand clearly displayed.High resolution and short processing time of the system,compared withother similar devices,make it suitable for engineering use.

Study on the transient radiation for apertures excited by rectangle pulse

The analytic representation of the transient radiation for an aperture excited by a rectangle pulse is obtained. It shows that the field duration and amplitude depend on the observation distance, the elevation angle, the pulse width of the rectangle pulse and the aperture size.

The dual role of multiple-transistor charge sharing collection in single-event transients

As technologies scale down in size, multiple-transistors being affected by a single ion has become a universal phenomenon, and some new effects are present in single event transients （SETs） due to the charge sharing collection of the adjacent multiple-transistors. In this paper, not only the off-state p-channel metal–oxide semiconductor field-effect transistor （PMOS FET）, but also the on-state PMOS is struck by a heavy-ion in the two-transistor inverter chain, due to the charge sharing collection and the electrical interaction. The SET induced by striking the off-state PMOS is efficiently mitigated by the pulse quenching effect, but the SET induced by striking the on-state PMOS becomes dominant. It is indicated in this study that in the advanced technologies, the SET will no longer just be induced by an ion striking the off-state transistor, and the SET sensitive region will no longer just surround the off-state transistor either, as it is in the older technologies. We also discuss this issue in a three-transistor inverter in depth, and the study illustrates that the three-transistor inverter is still a better replacement for spaceborne integrated circuit design in advanced technologies.

Impact of proton-induced alteration of carrier lifetime on single-event transient in SiGe heterojunction bipolar transistor

This paper presents an investigation into the impact of proton-induced alteration of carrier lifetime on the singleevent transient(SET) caused by heavy ions in silicon–germanium heterojunction bipolar transistor(SiGe HBT).The ioninduced current transients and integrated charge collections under different proton fluences are obtained based on technology computer-aided design(TCAD) simulation.The results indicate that the impact of carrier lifetime alteration is determined by the dominating charge collection mechanism at the ion incident position and only the long-time diffusion process is affected.With a proton fluence of 5 × 1013 cm-2, almost no change is found in the transient feature, and the charge collection of events happened in the region enclosed by deep trench isolation(DTI), where prompt funneling collection is the dominating mechanism.Meanwhile, for the events happening outside DTI where diffusion dominates the collection process, the peak value and the duration of the ion-induced current transient both decrease with increasing proton fluence, leading to a great decrease in charge collection.

Ionization process and distinctive characteristic of atmospheric pressure cold plasma jet driven resonantly by microwave pulses

In the present study,a coaxial transmission line resonator is constructed,which is always capable of generating cold microwave plasma jet plumes in ambient air in spite of using argon,nitrogen,or even air,respectively.Although the different kinds of working gas induce the different discharge performance,their ionization processes all indicate that the ionization enhancement has taken place twice in each pulsed periods,and the electron densities measured by the method of microwave Rayleigh scattering are higher than the amplitude order of 10^(18)m^(-3).The tail region of plasma jets all contain a large number of active particles,like NO,O,emitted photons,etc,but without O_(3).The formation mechanism and the distinctive characteristics are attributed to the resonance excitation of the locally enhanced electric fields,the ionization wave propulsion,and the temporal and spatial distribution of different particles in the pulsed microwave plasma jets.The parameters of plasma jet could be modulated by adjusting microwave power,modulation pulse parameters(modulation frequency and duty ratio),gas type and its flow rate,according to the requirements of application scenarios.

Investigation of time domain characteristics of negative capacitance FinFET by pulse-train approaches

The HfO2-based ferroelectric field effect transistors(FeFET)have been widely studied for their ability in breaking the Boltzmann limit and the potential to be applied to low-power circuits.This article systematically investigates the transient response of negative capacitance(NC)fin field-effect transistors(FinFETs)through two kinds of self-built test schemes.By comparing the results with those of conventional FinFETs,we experimentally demonstrate that the on-current of the NC FinFET is not degraded in the MHz frequency domain.Further test results in the higher frequency domain show that the on-state current of the prepared NC FinFET increases with the decreasing gate pulse width at pulse widths below 100 ns and is consistently greater(about 80%with NC NMOS)than the on-state current of the conventional transistor,indicating the great potential of the NC FET for future high-frequency applications.

Temporal pulsed x-ray response of CdZnTe:In detector

The temporal response of cadmium-zinc-telluride(CZT) crystals is evaluated at room temperature by using an ultrafast-pulsed x-ray source. The dynamics of carrier relaxation in a CZT single crystal is modeled at a microscopic level based on a multi-trapping effect. The effects of the irradiation flux and bias voltage on the amplitude and full width at half maximum(FWHM) of the transient currents are investigated. It is demonstrated that the temporal response process is affected by defect level occupation fraction. A fast photon current can be achieved under intense pulsed x-ray irradiation to be up to 2.78×10~9 photons mm-2·s-1. Meanwhile, it is found that high bias voltage could enhance carrier detrapping by suppressing the capture of structure defects and thus improve the temporal response of CZT detectors.

An experimental study of temperature and moisture content of wet porous materials under short-pulsed laser heating

The measurements of temperature and moisture content of a wet porous material were accomplished on the micro-seconds scale. The temperature wave was observed when the wet porous material was heated by short-pulsed laser with high power. It firstly revealed that the moisture content of wet porous material rapidly rises twice in one laser irradiation. The influences of laser parameters, the thickness and initial moisture content of the wet porous material on its temperature and moisture content were investigated.

太赫兹波段介质电磁参数测量与提取对比研究

本文完善了基于太赫兹时域光谱系统和基于矢量网络分析系统材料参数测量的一般理论,在2类系统的交叉频段,建立了相同准光学参数的测量条件,对比分析了2类系统信号参数测量和理论提取的过程。实验验证了在光子学和电子学的重叠区域,不同测量系统在相同测量条件下,能够获取趋于一致的测量结果,证实了结果的准确性只取决于物理模型、理论方法和测量条件是否匹配。提炼出采用单次时域法同时适用于时域系统和频域系统参数测量和提取的适配条件,并形成匹配条件经验理论公式,用于判断材料太赫兹参数测量结果的可靠性。

电快速瞬变脉冲群串扰耦合分析及防护措施研究

EFT产生的瞬态脉冲干扰可通过电缆耦合进入电子系统的内部,损伤电子设备。为降低瞬态脉冲对电缆串扰耦合的影响,首先利用电磁仿真软件CST建立平行电缆耦合仿真模型,当电压等级为4 kV时,测试电缆的近端串扰电压达到71.2 V,远高于部分敏感器件的阈值;然后通过分析电快速瞬变脉冲群的频谱特性,瞬态脉冲的干扰能量主要集中在1~10 MHz的范围内;最后利用仿真软件Filter Solution设计合理的防护电路。结果表明,防护电路能有效降低瞬态脉冲对电路的影响。

100 Mbps以太网端口的电快速瞬变脉冲群抑制装置

为了解决智能网联产品以太网端口的通信性能在电快速瞬变脉冲群试验中出现的非预期降级问题,研制了一款用于100 Mbps以太网端口的瞬态脉冲抑制装置。该装置的应用解决了以太网端口在±4 kV的电快速瞬变脉冲群干扰试验中出现的连接中断问题,并将±4 kV的电快速瞬变脉冲群干扰电压抑制至38.8 V,且不会引起以太网链路通信性能的明显下降。该研究为智能网联产品以太网端口的电快速瞬变脉冲群敏感度的准确判定提供了理论和技术支撑。

低频脉冲磁场诱导TRPC1改善COVID-19患者康复期下肢的肌肉无力症状

背景:肌肉无力是新型冠状病毒(COVID-19)感染后的常见症状,影响康复期人体日常活动能力。在强度1.5 mT,频率3300 Hz的低频脉冲磁场刺激下可通过诱导和激活经典瞬时感受器电位通1(classical transient receptor potential channel 1,TRPC1),提升人体骨骼肌的最大自主收缩力与力量耐力,对肌肉组织产生一系列生理支持效应,该手段是否会改善新型冠状病毒肺炎患者康复期的肌无力症状尚无研究。目的:选用低频脉冲磁场对新型冠状病毒肺炎患者下肢肌群进行磁刺激,以观察该刺激对新型冠状病毒肺炎患者康复期下肢肌群肌无力改善的影响。方法:招募胶体金法抗原检测试剂(COVID-19)为阳性并伴有肌肉无力症状的新型冠状病毒(奥密克戎毒株)感染患者14例,将所有受试者随机分成2组,分别为接受磁场刺激的试验组和接受假治疗的对照组。试验总时长3周,试验组每隔48 h对腿部进行低频脉冲磁刺激,对照组与试验组干预流程一致但给予假刺激,两组患者均不被告知磁刺激仪器是否运行,两组患者共进行9次操作,随后观察两组患者下肢局部肌群最大自主收缩力、腿部爆发力与力量耐力的变化情况。结果与结论:①在采集的8个局部肌群中,试验组患者7个局部肌群在经过3周的低频脉冲磁场刺激,最大自主收缩力值均增长。对照组除3个肌群最大自主收缩力自行增长改善以外,其他肌群肌力无提升。②试验组的左腿前群与双腿后群提升率显著高于对照组。③两组的纵跳摸高高度与膝关节峰值角速度相比试验前测均提升,试验组摸高高度提升率高于对照组。④在疲劳状态下,试验组膝关节峰值角速度下降率显著下降,对照组膝关节峰值角速度下降率无显著性变化;试验组摸高高度下降率显著下降,而对照组摸高高度下降率无显著性变化。⑤上述数据证实,在强度1.5 mT,频率3300 Hz的低频脉冲磁场刺激方案下,新型冠状病毒肺炎患者在康复期经过3周的低频脉冲磁场刺激相比人体自愈过程可使更多的下肢局部肌群肌力获得提升,对基于腿部爆发力的全身协调发力能力及功能状态明显改善。因此,低频脉冲磁场刺激可作为一种改善新冠感染患者下肢肌肉无力症状的有效、非运动的康复手段。

Single Event Transients of Operational Amplifier and Optocoupler

The single event transient effects of the operational amplifier LM124J and the optocoupler HCPL 5231 are investigated by a pulsed laser test facility. The relation of transient pulse shape to pulsed laser equivalent LET is tested,the sensitive areas of the SET effects are identified in voltage follower application mode of LM124J, and the mechanism is initially analyzed. The transient amplitude and duration of HCPL5231 at various equivalent LET are examined,and the SET cross-section is measured. The results of our test and heavy ion experimental data coincide closely,indicating that a pulsed laser test facility is a valid tool for single event effect evaluation.