A novel single event upset reversal in 40-nm bulk CMOS 6T SRAM cells

In advanced technologies, single event upset reversal(SEUR) due to charge sharing can make the upset state of SRAM cells recover to their initial state, which can reduce the soft error for SRAMs in radiation environments. By using the full 3D TCAD simulations, this paper presents a new kind of SEUR triggered by the charge collection of the Off-PMOS and the delayed charge collection of the On-NMOS in commercial 40-nm 6 T SRAM cells. The simulation results show that the proposed SEUR can not occur at normal incidence,but can present easily at angular incidence. It is also found that the width of SET induced by this SEUR remains the same after linear energy transfer(LET) increases to a certain value. In addition, through analyzing the effect of the spacing, the adjacent transistors, the drain area, and some other dependent parameters on this new kind of SEUR, some methods are proposed to strengthen the recovery ability of SRAM cells.

Knowledge Discovery for Event Series Decision Based on Rough Set

To make decisions about event series is part of our life, and to discover knowledge from these decisions is of great significance in the field of controlling and decision-making. The paper takes event series as the exterior form of movements with the dynamic attributes, and gets the Markov transition probabilities matrix to express those attributes with statistics. First, according to the matrix, the decision table is constructed. Then, by reducing attributes based on rough set theory, the decision table is reduced, and the decision rules are acquired as well. Finally we make the decision through defining rule distance and taking the minimum rule distance as decision principle. Followed is an example, which proves that the algorithm is feasible and effective to the event series decision.

Single-event-transient effect in nanotube tunnel field-effect transistor with bias-induced electron–hole bilayer

The single event transient(SET)effect in nanotube tunneling field-effect transistor with bias-induced electron–hole bilayer(EHBNT-TFET)is investigated by 3-D TCAD simulation for the first time.The effects of linear energy transfer(LET),characteristic radius,strike angle,electrode bias and hit location on SET response are evaluated in detail.The simulation results show that the peak value of transient drain current is up to 0.08 m A for heavy ion irradiation with characteristic radius of 50 nm and LET of 10 Me V·cm^(2)/mg,which is much higher than the on-state current of EHBNTTFET.The SET response of EHBNT-TFET presents an obvious dependence on LET,strike angle,drain bias and hit location.As LET increases from 2 Me V·cm^(2)/mg to 10 Me V·cm^(2)/mg,the peak drain current increases monotonically from 0.015 mA to 0.08 mA.The strike angle has an greater impact on peak drain current especially for the smaller characteristic radius.The peak drain current and collected charge increase by 0.014 mA and 0.06 fC,respectively,as the drain bias increases from 0.1 V to 0.9 V.Whether from the horizontal or the vertical direction,the most sensitive hit location is related to wt.The underlying physical mechanism is explored and discussed.

NBTI效应导致SET脉冲在产生与传播过程中的展宽

本文研究了负偏置温度不稳定性(NBTI)对单粒子瞬态(SET)脉冲产生与传播过程的影响.研究结果表明:NBTI能够导致SET脉冲在产生与传播的过程中随时间而不断展宽.本文还基于工艺计算机辅助设计模拟软件(TCAD)进行器件模拟,提出了一种在130nm体硅工艺下,计算SET脉冲宽度的解析模型,并结合NBTI阈值电压退化的解析模型,建立了预测SET脉冲宽度在产生的过程中随PMOS器件的NBTI退化而不断展宽的解析模型,TCAD器件模拟的结果与解析模型的预测一致;本文还进一步建立了预测SET脉冲宽度在传播的过程中随PMOS器件的NBTI退化而不断展宽的解析模型,SPICE电路模拟的结果与解析模型所预测的结论一致.

我国中考体育方案的实施状况、总体特征与优化路径——以省级、副省级城市为例

通过文献资料法、调查法、比较分析法和数理统计法,对19座省级、副省级城市的中考体育方案进行分析。发现,中考体育的分值设置有所提升,但较分散;分值权重有所增加,但较语数外仍有差距;必考项目+选考项目成为当前主流的项目设置模式;中考满分标准与国家标准接近,但整体低于国家标准。认为,中考体育分值和权重的提升成为必然趋势,“过程性评价+终结性评价”成为主流模式,多元化评价内容建构成为发展方向。未来中考体育要以体教融合为契机,推进中考体育方案改革;落实“双减”政策精神,完善过程性评价细则;增加技能类考试项目,合理设计项目考试方案;提升测试项目的满分标准,增加成绩评价的区分度。旨在更好推进中考体育改革,增进青少年体质健康。

运算放大器SET效应的试验研究

模拟器件的单粒子瞬态脉冲效应的研究,成为近来国际上单粒子效应研究的热点.针对中国生产的运算放大器SF3503,利用脉冲激光单粒子效应测试装置,试验研究了SF3503工作于反相放大器与电压比较器模式SET效应的特征与规律.获取了器件的敏感节点分布、LET阈值和SET脉冲波形的特征参数,其中器件的敏感节点均分布在输入级与放大级,LET阈值不大于1.2 MeV·cm~·mg^(-1),电压比较器产生的最大SET脉冲的幅度达27V、脉冲宽度为51μs.试验表明SF3503对SET效应极其敏感,在不采取任何措施的情况下,在空间任务中直接使用,会严重影响系统的可靠性.

不同能量质子辐照CMOS图像传感器的单粒子瞬态效应研究

针对空间环境宽能谱质子辐射导致的CMOS图像传感器单粒子效应问题,开展了不同能量质子辐照试验,研究了质子辐照导致CMOS图像传感器单粒子效应的异常现象、图像特征及参数性能变化规律。试验表明,质子辐照主要导致CMOS图像传感器出现明显的单粒子瞬态(single event transient,SET)效应现象,包括SET亮斑和亮线。通过对比不同条件下的试验结果,分析了质子能量、积分时间等变化对SET亮斑覆盖像素情况、信号水平的影响规律,并结合TCAD仿真工具,分析了SET亮斑的产生机制。研究结果表明:SET亮斑灰度水平和覆盖像素数目均随辐照质子能量增加而增大;SET亮斑覆盖像素最大灰度值、平均灰度值随CMOS图像传感器积分时间增加而增大,通过调节CMOS图像传感器的积分时间,可以明显改变SET亮斑的特征和器件成像性能;从TCAD软件仿真的微观物理过程获得了SET亮斑随积分时间变化的机制,支持了对试验结果的分析和判断。研究结果可为CMOS图像传感器空间辐射效应评估、抗辐射加固提供试验和理论参考。

基于实例分布约束的事件语义自动划分

针对离散分布于新闻文本集合中的事件语义难以聚合的问题,提出了基于实例分布约束的事件语义自动划分算法。首先,利用远程监督方法,构建用于事件语义划分的训练数据集;其次,设计基于实例分布约束的事件语义分类器,用于判断新的事件触发词的加入是否影响事件语义的聚合;最后,在该分类器的基础上设计事件语义集合生成算法,在不需要预先设定事件类型的情况下,将分布离散的事件触发词自动地划分到不同的事件语义集合中。结果表明本方法可有效实现事件语义的自动划分,为事件语义的高质量聚合提供了一种新的探索。

基于SimEvents仿真获取网络不交化最小路集

从信息传递角度,将Co A网络转换为具有前向和逆向传输路径的信息传输网络;在对网络不交化MPs(Minimal Path sets)算法原理分析基础上,设计了信息在网络中的传输和改写规则(包括正向和逆向传输规则),并以离散事件仿真(Discrete Event Simulation,DES)为手段,对网络建模,对算法实现。以Sim Events为平台,阐述了基于DES进行算法实现的基本思路:即以实体(Entity)为信息载体,以节点为暂存和处理单元。仿真过程中,信息随实体在网络中传输,并不断改写,直至完成不交化MPs的生成。对桥型网络和复杂网络的仿真结果验证了信息处理规则的正确性,和基于DES进行算法实现的可行性。

一种新型SEU/SET加固鉴频鉴相器设计

分析验证了传统D触发器型PFD结构的SEE敏感性,提出了一种新型的SEU/SET加固鉴频鉴相器,SPICE模拟结果表明该结构功能正确,对于1GHz的时钟信号,鉴频鉴相的精度可达0.8rad。锁相环的整体模拟结果表明,抗辐照的PFD与传统的PFD相比,锁相环的电学性能没有改变,锁定时间保持一致。对传统D触发器型PFD和设计加固的PFD进行了遍历轰击模拟,结果显示,提出的抗辐照PFD加固效果非常明显,敏感节点的数目可以降低80%左右。

系统故障演化过程中事件状态联系数构建研究

由于故障数据提取、表示、分析和处理过程存在不确定性,给系统故障演化过程研究带来困难,为此,提出一种基于集对分析联系数的系统故障演化过程事件状态联系数构建方法。基于联系数对多语义状态划分及同异反状态的表示分析能力,以系统安全为目标进行研究。分析已有精确系统故障演化过程分析方法的不足;将事件发生概率分布划分为安全、不确定、不安全三状态等效同异反状态,进而确定状态分项系数得到事件状态联系数;通过同异反真值表确定结果事件状态联系数。结果表明,得到的事件状态联系数符合联系数构造条件和逻辑真值关系,进而获得系统故障演化过程的事件演化表示方法,也可使用集对分析的已有方法进行相关研究。研究搭建集对分析理论与系统安全分析的桥梁,将蕴含不确定数据的定量分析发展为不确定性分析,化简分析过程并体现同异反特征。

基于GFScom的广义可能性Kriple结构中事件建模方法

为了处理系统验证中大量存在的不确定性,国内学者将可能性理论引入到模型检测中,提出了广义可能性Kriple结构。广义可能性Kriple结构有着较好的应用前景,但有许多问题需要解决。其中的一个问题是,如何高效便捷地建立广义可能性Kriple结构的数学模型。为了给广义可能性Kriple结构中的模糊事件提供一种便捷方便的建模方法,在建模的过程中引入具有三种否定的广义模糊集(Generalized Fuzzy Sets with Contradictory,Opposite and Medium negation,GFScom),给出了广义可能性Kriple结构中的模糊事件的建模方法。应用实例表明所提方法是有效、可行的。

基于FPGA的微处理器SET敏感性评估方法

为了快速准确地的评估微处理器单粒子瞬态(single event transient,SET)软错误敏感性,文章提出了一种改进的基于现场可编程门阵列(field programmable gate array,FPGA)故障注入的软错误敏感性评估方法。该方法通过分析微处理器门级网表和时序文件,提取SET故障注入位置和传输延时信息,使用扫描链实现SET故障脉冲的注入,同时考虑了时窗屏蔽效应、逻辑屏蔽效应和电气屏蔽效应对SET故障脉冲传播的影响;并使用该方法对PIC16F54微处理器进行了故障注入。实验结果表明,基于该方法进行故障注入及软错误敏感性评估所需的时间比Isim软件仿真方法提高了约4个数量级。

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.

基于Rosetta软件和Vague集的战术机动事件检测方法

事件检测是态势觉察的重要内容,是对当前战场态势变化的感知,是态势估计的基础,能否正确检测出当前战场所发生的有意义的行为,直接影响到了态势估计的结果。提出一种基于Rosetta软件和Vague集的战术机动事件检测方法,将目标历史数据离散化,建立事件决策表;利用Rosetta软件中的遗传算法约简方法对事件决策表进行约简,得到简约决策表;将实时检测到的目标状态变化离散化,根据简约决策表建立Vague集;计算事件的相似度,根据评价体系,判断发生何种事件。仿真结果表明,这种事件检测方法,较大地提高了检测的正确率。

组合电路SET传播特性与软错误率分析

通过研究单粒子瞬态(Single Event Transient,SET)在逻辑链路中的传输,表明输入脉冲宽度对脉冲在传输过程中的展宽和衰减有重要影响.在辐照环境下,采用SET的传输模型和软错误率的分析模型评估软错误率.基于这两种模型,从门级角度对组合电路的软错误率分析进行了改善,使得软错误率评估方法得到改进.由于电气掩蔽效应对软错误分析具有重要的影响,在运用SET传输模型中考虑了电气掩蔽特性.

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.

煤矿掘进多行为协同控制智能决策模型

智能决策支持的掘进多行为协同控制是煤矿掘进工作面智能化的核心之一,掘进多行为协同控制的最优时序规划是智能决策的关键。针对煤矿掘进多行为控制模式单一、固化、协同作业能力差等问题,设计了一种煤矿掘进多行为协同控制智能决策模型,实现了掘进多行为在最优时序下的协同作业。首先,提出了掘进多行为协同控制智能决策方法,确定了掘进多行为可行时序规划集和多目标最优时序规划策略;其次,根据掘进现场的规定和工艺要求,确定了掘进动作事件集,通过对事件集中两两动作事件之间时间关系的分析,求出掘进多行为时间关系约束矩阵;然后,根据时间点关系约束矩阵转换方法,将掘进多行为时间关系约束矩阵转换为时间点关系约束矩阵,再求出掘进多行为可行时序规划集;最后,定义不同掘进目标下的求解函数,求得不同掘进目标的最优时序。实验结果表明,在不同掘进目标下,按照模型决策出的掘进动作最优时序规划结果,掘进机器人可无干涉协同作业,且掘进作业1个工作循环的执行时间与决策模型计算的时间基本一致。

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.