Analysis of process variations impact on the single-event transient quenching in 65 nm CMOS combinational circuits

Single-event transient pulse quenching(Quenching effect)is employed to effectively mitigate WSET(SET pulse width).It enhanced along with the increased charge sharing which is norm for future advanced technologies.As technology scales,parameter variation is another serious issue that significantly affects circuit’s performance and single-event response.Monte Carlo simulations combined with TCAD(Technology Computer-Aided Design)simulations are conducted on a six-stage inverter chain to identify and quantify the impact of charge sharing and parameter variation on pulse quenching.Studies show that charge sharing induce a wider WSET spread range.The difference of WSET range between no quenching and quenching is smaller in NMOS(N-Channel Metal-Oxide-Semiconductor Field-Effect Transistor)simulation than that in PMOS’(P-Channel Metal-Oxide-Semiconductor Field-Effect Transistor),so that from parameter variation view,quenching is beneficial in PMOS SET mitigation.The individual parameter analysis indicates that gate oxide thickness(TOXE)and channel length variation(XL)mostly affect SET response of combinational circuits.They bring 14.58%and 19.73%average WSET difference probabilities for no-quenching cases,and 105.56%and 123.32%for quenching cases.     

Simulation analysis of heavy-ion-induced single-event response for nanoscale bulk-Si FinFETs and conventional planar devices

FinFET technologies are becoming the mainstream process as technology scales down. Based on 28-nm bulk-Si FinFETs and planar transistors, three-dimensional technology computer-aided design (TCAD) simulations are performed to investigate the charge collection mechanisms and single-event transient (SET) pulse widths for nanoscale devices. Simulation results show that charge collection and SET pulse widths for FinFETs are smaller than those of the planar device. An overall analysis indicates that for P-hits, the reduced charge collection in p-FinFET is induced mainly by the narrow sensitivity drain volumes when ion linear energy transfer (LETs) less than 20 MeV cm²/mg; however, the parasitic bipolar amplification effect presents an important effect on the charge reduction for higher ion LETs. An in-depth analysis shows that the reduced bipolar amplification effect in p-FinFET is owing to the conduction channel (fin body) rather than source/drain region. Due to a parasitic reversed bipolar effect, the single-event response for N-hit is less sensitive than that for P-hit. Moreover, comparisons of the temperature dependence of SET pulse width in both FinFETs and planar devices is carried out, which indicate that the SET pulse width in PMOS shows stronger temperature dependence than that in p-FinFET. This gives a new insight into the single-event effects (SEE) in FinFETs, which can provide guidelines for future radiation-hardened applications of FinFET-based circuits.     

基于SET/MOS混合结构的4-2编码器设计

基于单电子晶体管（SET）的库仑振荡效应、多栅输入特性和相移特性,实现了SET/MOS混合结构的或门逻辑,并利用该或门逻辑实现了4-2编码器。利用HSPICE对所设计电路进行仿真验证,仿真结果表明该电路能够实现4-2编码器的编码功能。与纯CMOS编码器相比,该SET/MOS混合电路仅由2个PMOS管、2个NMOS管和2个SET构成,具有结构简单、尺寸小、集成度高的优点。     

低导通电阻沟槽栅极LIGBT的模拟研究

横向绝缘栅双极晶体管(LIGBT)采用少数载流子的注入来降低导通电阻,完成了5μm外延层上普通LIGBT(C-LIGBT)、3μm外延层上的Trench Gate LIGBT(TG-LIGBT)设计及仿真.研究了利用沟槽结构改善LIGBT的正向特性和利用RESURF技术改善TG-LIGBT的反向特性.通过Silvaco TCAD软件验证了了击穿电压大于500 V的两种结构LIGBT设计,实现了导通压降为1.0 V,薄外延层上小元胞尺寸,且有低导通电阻、大饱和电流的TG-LIGBT器件.     

等离子体边缘损伤的横向分布测量

等离子体刻蚀工艺中，栅边缘直接暴露在等离子体环境中，UV射线和粒子轰击会在栅漏交叠区栅氧化层中和硅二氧化硅界面处产生大量的陷阱，这些陷阱的分布和数量对器件的长期可靠性将会产生重大的影响，采用低频电荷泵技术测量了栅边缘损伤的横向分布，为评估栅边缘损伤提供了一个良好的手段。     

闸门对河道污染物影响的模拟研究

通过明渠水槽模拟的闸门调控实验,初步认识了闸门影响下污染物迁移转化波形分布规律.实验结果表明,通过合理调度,闸门在一定开度下可以起到既保证上游污染物通过闸门、减少闸前污染物质的聚集,又可降低闸下河道沿程的污染物浓度分布的作用,为进一步在实践中确定合理的考虑污染控制的闸坝调控方案提供了实验依据.为进一步认识闸门调控下污染物迁移规律,本文采用实验数据,建立了模拟河道流量、闸上游水位、闸前污染物浓度、闸门高度与闸下游各断面的污染物浓度之间复杂非线性关系的BP神经网络模型,网络学习和检验都取得了较高的精度,表明了人工神经网络在闸门对河道污染物影响的模拟与预测中的可行性和实用性.     

同步脉宽调制式高分辨力ADC研究

同步V/F转换器由于其输出频率的相位调制特性,以及输出频率上限的限制,影响了其分辨力的进一步提高。采用电荷平衡与双斜式原理相结合的同步V/F转换技术,可提高其分辨力。该文提出一种基于双比较器定电压的同步脉宽调制新技术,在定电压积分的基础上,通过较高的同步时钟脉冲自动"微调"积分时间,实现了一个周期内电荷的充分平衡。通过多周期测量,实现了各周期内电荷动态平衡调节效果。经实验验证和测试表明,分辨力达5位,最小二乘法拟合线性度优于0.005%。     

N型LDMOS器件在关态雪崩击穿条件下的退化

针对功率开关管在未箝位电感性开关转换时会反复发生雪崩击穿,引起器件参数退化的问题,对一种20 V N型横向双扩散MOS器件(NLDMOS)在关态雪崩击穿条件下导通电阻的退化进行研究.通过恒定电流脉冲应力测试、TCAD（technology computer aided design）仿真和电荷泵测试,分析研究导通电阻退化发生的区域及退化的微观机理,并针对实验结果提出2种退化机制：(1) NLDMOS漂移区中的空穴注入效应,这种机制会在器件表面产生镜像负电荷,造成开态导通电阻Ron的减少;(2)漂移区中的表面态增加效应,这种机制会造成载流子迁移率的下降,引起Ron的增加.这2种机制都随着雪崩击穿电流的增加而增强.     

一种精简的高速率功率MOS驱动器

设计了一种具有新颖的死区产生方法的高压功率MOS驱动电路,利用电阻调节驱动MOS管栅极电容充放电的时延,来产生极短的死区时间,可精简电路结构,提高驱动速率,并且无需电流偏置,就能有效降低电流源噪声．基于0.4μm BCD工艺,经Cadence环境下进行仿真验证．结果表明,该驱动电路能够产生10ns以下的死区时间,且传输时延低于70ns．对采用该驱动电路的一款功率因数校正芯片进行测试,驱动输出开关信号的上升沿时间为90ns,下降沿时间为55ns．功率因数可达0.995,总谐波失真为6.5％．     

光纤开度仪在大型船闸中的应用

采用两大先进技术一无丌传感技术与可编程控制技术,研制出了一种新型的光纤开度仪。将其应用于大型船闸闸门(特别是多级船闸)的开度测控,实现了光测光传,提高了检测中的自动化程度。该套系统测量范围宽、测量精度高,重复测量稳定性好及抗干扰能力强,它的应用成功地解决了大型船闸闸门系统的检测与拉制技术难题     

新型流水线ADC的设计与分析

设计和分析了一种新型的流水线式模数转换器。电路设计主要包括一种开关采样差分折叠式共源共栅增益级、两个时钟控制动态比较器组成的两位模数转换器、两位数模转换器。由于采用了电容下极板采样、全差分和开关栅电压自举,有效地消除了开关管的电荷注入效应、时钟馈通效应引起的采样信号的误差,提高了模数转换器的线性度、信噪比、转换精度和速度。该转换器的设计是在0.6 μm CMOS工艺下实现,转换器在采样频率为5 MHz、信号频率为500 kHz时功耗为70 mW;SFDR为80 dB。     

试论工科院校中的学生评教工作

学生评教是高等工程教育质量监控体系中的一个重要的环节。工科院校只有重视学生评教的理论和实践问题的研究,才能使学生评教工作尽可能大地发挥正面效应。本文阐述了学生评教的法律依据和时代精神、意义和怍用;肯定了学生评教的可信性和有效性;归纳了制定学生评教表的基本原则;分析了影响学生评教效果的人为因素。     

Analyzing and mitigating the internal single-event transient in radiation hardened flip-flops at circuit-level

Internal SET has become a great concern in normal radiation-hardened flip-flops with increases in frequency. We investigate the internal SET problem in the traditional hardened flip-flops in this article. We also propose a novel structure to eliminate the internal SET problem. Three-dimensional technology computer-aided design (TCAD) was adopted to verify the hardened performance of this proposed novel structure. Besides, the power and setup time were compared with the traditional hardened flip-flops.     

大型翻板闸门流体激振的双模型试验研究

针对水工闸门的流激振动普遍存在的情况下，振动强度难以预测的问题，通过双模型试验获得结构振动响应特征，即通过变态相似的水力学模型试验获得流体激振载荷功率谱密度，借助严格比例的结构模型试验获得液固耦合下的结构分析点的传递函数，通过数值计算得到不同工况下闸门过流时的振动随机响应特征.在某大型翻板闸门的应用结果表明，该方法合理有效，通过模型试验与随机响应计算，预测实际流激振动的随机响应特征量；门顶过流时该闸门的振动响应集中在低频段，不会产生共振现象，同时该闸门对波浪载荷作用将是敏感的，必须给予充分关注.     

凤滩弧形闸门局部开启原型振动试验研究

采用先进的电子测量技术测定了凤滩水电厂弧形闸门原型的动力特性和局部开启时结构的振动反应．对闸门振动现象及机制进行了探讨，指出了闸门开启运行时的最不利泄流位置，为同类型闸门作局部开启运行提供了有益的参考依据     

基于SOA-MZI差分相位法的全光异或逻辑门研究

建立了基于SOA-MZI结构差分相位法的全光异或逻辑门模型,实现了20 Gbit/s信号的全光异或逻辑运算.运算结果表明:输出脉冲信号的宽度主要是由延迟时间t决定的.采用差分相位法,可以减弱输出脉冲的码型效应,避免出现“拖尾”现象.     

基于传感器阵列的油品分层系统的研究与设计

针对目前油品含水率测量存在的油污的问题,设计了6电极电容传感器阵列,以此来解决单个或少量传感器探头易被油污污染,严重影响决策判断的问题．针对电路中漏电流问题进行了电路的改进,采用D触发器来控制两个互补时序的开关,比单纯用非门的方法能减少大概几十纳秒的电荷泄漏时间,能较好的改善漏电流的问题．设计了基于PC机WINDOWS操作系统的实验数据采集与分析系统,试验证明所设计的传感器阵列与数据采集系统能够达到预期的简单液体层次分离的效果．     

Application of ventilation simulation to spontaneous combustion control in underground coal mine: A case study from Bulianta colliery

Spontaneous combustion of residual coal in longwall goaf is a long standing hazard. Airflow leakage into goaf is a major driver to the hazard and this issue deteriorates where longwalls are operating in multiple seams and shallow covers because mining-induced cracks are very likely to draw fresh airflow into goaf due to presence of pressure differential between longwall face and surface. To study the problem more critically, a ventilation simulation package ‘‘Ventsim" is used to conduct a case study from Bulianta colliery. It was found that isolating and pressurizing active longwall panel can mitigate the problem and the pressure differential can be adjusted by varying performance of auxiliary fan and resistance of ventilation regulator. A booster ventilation system can also mitigate the problem by adjusting fan duties. Ventilation simulation is a powerful tool to study spontaneous combustion control in underground coal mine.     

SET安全机制分析

SET(Secure Electronic Transaction)是在互联网上进行在线交易时保证银行卡安全支付的一个开放协议,其特点是高安全性,具有良好的可操作性.文章对该协议的流程和二次签名机制进行了详细的分析和说明.     

土工格室处理高速公路拓宽结合部分析

为了解土工格室处理高速公路拓宽结合部的效果,使加宽部分路堤和既有道路更为紧密地衔接形成整体,减少新老路堤的不均匀沉降,应用有限元分析土工格室铺于新老路基结合处不同层位时路基顶面各关键点的侧向位移、竖向沉降和最大差异沉降.结果表明,土工格室的铺设可以减少路基的侧向位移和差异沉降,且铺于基底和基顶时效果最好,可以提高路基整体刚度和地基承载能力.