Experimental study on heavy ion single-event effects in flash-based FPGAs

With extensive use of flash-based field-programmable gate arrays(FPGAs) in military and aerospace applications, single-event effects(SEEs) of FPGAs induced by radiations have been a major concern. In this paper, we present SEE experimental study of a flash-based FPGA from Microsemi Pro ASIC3 product family. The relation between the cross section and different linear energy transfer(LET) values for the logic tiles and embedded RAM blocks is obtained. The results show that the sequential logic cross section depends not too much on operating frequency of the device. And the relationship between 0 →1 upsets(zeros) and 1 →0 upsets(ones) is different for different kinds of D-flip-flops. The devices are not sensitive to SEL up to a LET of 99.0 Me V cm2/mg.Post-beam tests show that the programming module is damaged due to the high-LET ions.     

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.     

NT50型中子管离子源磁场变化对放电电流的影响

通过NT50型中子管离子源放电特性实验,研究潘宁离子源磁场变化对放电电流产生的影响.得到磁场变化相对放电电流的关系曲线,进行数据分析,发现离子源放电规律,从而找出其最佳工作状态和工作参数,提高中子管产品质量.     

Nuclear microprobe imaging of single-event upsets

An imaging technique has been developed which produces micron-resolution maps of where single-event upsets occur during ion irradiation of integrated circuits. From these `upset images' the identity and size of a circuit's upset-prone components can be directly determined. Utilizing a scanning nuclear microprobe, this imaging technique selectively exposes the lowest functional units of an integrated circuit (e.g. transistor drains, gates) and immediately measures the effect of a high-energy ion strike on circuit performance. Information about an integrated circuit's radiation hardness (i.e. total dose response and threshold upset LET), which has previously been acquired at the circuit level, can also be measured at the individual transistor level. Such detailed spatial characterization, provides a novel precision diagnostic technique with which to study single-event upset processes in integrated circuits     

Mass spectrometry improvement on an high current ion implanter

The development of accurate mass spectrometry, enabling the identification of all the ions extracted from the ion source in a high current implanter is described. The spectrometry system uses two signals (x-y graphic), one proportional to the magnetic field (x-axes), taken from the high-voltage potential with an optic fiber system, and the other proportional to the beam current intensity (y-axes), taken from a beam-stop. The ion beam mass register in a mass spectrum of all the elements magnetically analyzed with the same radius and defined by a pair of analyzing slits as a function of their beam intensity is presented. The developed system uses a PC to control the displaying of the extracted beam mass spectrum, and also recording of all data acquired for posterior analysis. The operator uses a LabVIEW code that enables the interfacing between an I/O board and the ion implanter. The experimental results from an ion implantation experiment are shown.     

Comparative study of transient current induced in SiC p+n and n+p diodes by heavy ion micro beams

N⁺p and p⁺n diodes were fabricated on p- and n-type 6H–SiC substrates with epitaxial layers, respectively. The charge induced in the diodes by 9 MeV oxygen (O) and nickel (Ni) ions was measured using Transient Ion Beam Induced Current (TIBIC) to clarify the capability of these diodes as particle detectors. As a result of the TIBIC measurements using 9 MeV O, the Charge Collection Efficiency (CCE) of around 83% was obtained for both p⁺n and n⁺p diodes. Since the CCE value includes the consumption of incident ion energy in an Al electrode and the n⁺ (p⁺) region as well as the decay of charge in the measurement system, the CCE value obtained in this study indicates that SiC n⁺p as well as p⁺n diodes are suitable for particle detectors. On the other hand, in the case of 9 MeV Ni ion irradiation, the CCE for both n⁺p and p⁺n diodes decreases due to the Auger recombination in dense electron–hole pairs.     

Effect of transient heating loads on beryllium

Beryllium will be used as a plasma facing material for ITER first wall. It is expected that erosion of beryllium under transient plasma loads such as the edge-localized modes (ELMs) and disruptions will mainly determine a lifetime of ITER first wall. The results of recent experiments with the Russian beryllium of TGP-56FW ITER grade on QSPA-Be plasma gun facility are presented. The Be/CuCrZr mock-ups were exposed to upto 100 shots by deuterium plasma streams with pulse duration of 0.5 ms at ∼250 °C and average heat loads of 0.5 and 1 MJ/m². Experiments were performed at 250 °C. The evolution of surface microstructure and cracks morphology as well as beryllium mass loss are investigated under erosion process.     

CG-100强流离子注入机

离子注入机经过20多年的发展,其主要技术指标已达较高水平。最近几年除了用于半导体掺杂的弱流机外,用于材料改性的强流机及用于超大规模集成电路研制的高能、超高能(MeV)注入机都有了较大的发展。     

强流双潘宁离子源弧特性研究

针对22cm双潘宁离子源,研究了其弧流与放电调节参数的关系以及二次进气的效果,确定了拉长弧流脉宽、提高弧流强度与稳定性、达成离子源合适工作状态的措施,为获得高品质的弧流提供了依据.离子源弧特性测试研究结果对提高强流离子源的工作性能以实现NBI系统强流准稳态运行有重要的指导意义.     

金属真空弧离子源引出强流离子束的数值模拟

为了引出更高强度、更高亮度的铀离子束,以满足重离子研究中心(Gesellschaft für SchwerionenforschungmbH,GSI)重离子同步加速器的需求,本文用三维的计算机程序KOBRA3-INP对金属真空弧离子源(Metalvapor vacuum arcion source,MEVVA)引出强流铀离子束在引出系统和后加速系统中的动力学特性进行了研究,讨论了离子源发射束流密度对引出束性能的影响.结果表明,束流损失主要发生在引出系统和后加速系统之间的漂移区;在假设漂移区束流被空间电荷中和的情况下,模拟结果和实验结果符合;在发射束流密度为180-230 mA/cm2范围内,经后加速的束流强度变化不大.     

Effect of the laser focus position on characteristics of X-ray and ion emission from gold plasmas generated by a sub-nanosecond laser

X-ray and ion emission from gold plasma produced by a sub-nanosecond Nd:glass laser has been studies as a function of distance of the target from the best focus position. Thermal ion (kinetic energy <19 keV) signals and soft X-ray flux (photon energy >0.7 keV) measurements decrease as the target is moved closer to the best focus position in spite of an increase in laser intensity. We observe simultaneously a strong correlation between the onset of this drop in the flux of soft X-ray and the growth of harder X-ray (photon energy 3–5 keV), alongside a growth in fast ion (energy >67 keV) numbers. This is indicative of the onset of non-linear processes at the higher irradiances (～10¹⁴ W/cm²) associated with the best focus position. Our results show that when using laser plasmas as X-ray or ion sources, X-ray and ion emission in a desired spectral range can be optimized by adjusting the focusing on the target.     

单粒子效应不同模拟源的等效性实验研究初探

地面模拟单粒子效应(Single event effect,SEE)采用的模拟源主要有加速器(重离子加速器、高能质子加速器)、天然放射源(锎裂变碎片源)和脉冲激光模拟源.本文针对三种不同的模拟源(脉冲激光、重离子、锎源),开展IDT6116 SRAM单粒子效应不同模拟源的等效性实验研究,探索三种不同的模拟源评估器件和集成电路抗单粒子效应敏感性的等效性,并将三种不同的模拟源的实验结果进行分析比对,比对结果表明,三种不同模拟源模拟实验取得的实验结论基本一致.     

The Legnaro ion microprobe in low current experiments

The focused ion microprobe of the Laboratori Nazionali di Legnaro has been recently employed in experiments requiring very low beam current. This article will discuss the performance of our apparatus in this application, the drawbacks which showed up and the appropriate solutions. We present IBIC observations of grain boundaries in polycrystalline silicon solar cells and IBIC and IBIL measurements on CVD diamond samples. The modifications introduced in the experimental setup are outlined. We emphasise the problems typical of these measurements and propose the interposition of thin gold foils in the beam line, as a way to handle very different current intensities. We study the effects of these foils on beam quality and their effectiveness in reducing the current. A new designed system for easy interchange of foils and related collimators is described, which will be inserted upstream in the beam line.     

Limiting current density in a linear ion accelerator

The differential equation of the separatrix is found for the initial section of a linear ion accelerator in which the diameter of the group of particles is much greater than its length; the solution of the equation is obtained for three forms of stationary charge-density distribution function in phase space. The solution enables the limiting or saturation current density in the accelerator to be determined.Translated from Atomnaya Énergiya, Vol. 21, No. 5, pp. 356–360, November, 1966.     

Modern applications of high energy ion beams: from “single-event burnout” to human eye cancer treatment

Energetic ion beams, originally the domain of nuclear physics, become increasingly important tools in many other fields of research and development. The choice of ion species and ion energy allows an enormously wide variation of the penetration depth and of the amount of the electronic stopping power. These features are utilized to modify or damage materials and living tissues in a specific way. Materials modification with energetic ion beams is one of the central aims of research and development at the ion beam laboratory, ISL-Berlin, a center for ion-beam applications at the Hahn-Meitner-Institut Berlin. In particular, energetic protons will be used for eye cancer treatment. Selected topics such as the “single-event burnout” of high power diodes and the eye cancer therapy setup will be presented in detail.     

Mapping of ion beam induced current changes in FinFETs

We report on progress in ion placement into silicon devices with scanning probe alignment. The device is imaged with a scanning force microscope (SFM) and an aligned argon beam (20 keV, 36 keV) is scanned over the transistor surface. Holes in the lever of the SFM tip collimate the argon beam to sizes of 1.6 μm and 100 nm in diameter. Ion impacts upset the channel current due to formation of positive charges in the oxide areas. The induced changes in the source–drain current are recorded in dependence of the ion beam position with respect to the FinFET. Maps of local areas responding to the ion beam are obtained.     

Experimental study of temperature dependence of single-event upset in SRAMs

We report on the temperature dependence of single-event upsets in the 215–353 K range in a 4M commercial SRAM manufactured in a 0.15-lm CMOS process,utilizing thin film transistors. The experimental results show that temperature influences the SEU cross section on the rising portion of the cross-sectional curve(such as the chlorine ion incident). SEU cross section increases 257 %when the temperature increases from 215 to 353 K. One of the possible reasons for this is that it is due to the variation in upset voltage induced by changing temperature.     

Ion microscopy using magnifying ion TRANSPORT systems and position sensitive detectors

Microanalysis by detection of charged particles may be speeded up by several orders of magnitude when position sensitive detectors are used at the focus of a magnifying lens system. Using beam optics calculations a resolution on the sample of 40 × 7 μm² appears possible with available quadrupoles with an acceptance of 0.375 msr selecting particle energy within a 1.2% range. Even submicron resolution may be possible when energy is selected within a 0.3% range. The projection system has an appreciable field of view: sample regions of the order of 1 mm² may be studied simultaneously when appropriate detectors are used.