电子元器件屏蔽封装材料的屏蔽效果

针对电子元器件屏蔽封装材料的屏蔽效果评估方法及理论计算在器件屏蔽封装中应用的问题,本文通过理论计算一种屏蔽材料对1.0MeV电子的屏蔽效果,以及对应的实验验证,指出此种屏蔽材料有很好的屏蔽电子辐射作用.研究证明了理论与实验相互验证的方法能很好的评估屏蔽材料的屏蔽效果,同时指出理论计算的结果能在屏蔽材料设计中作为依据.     

栅控横向PNP双极晶体管辐照感生电荷的定量分离

设计并制作了一种栅控横向PNP双极晶体管测试结构,在常规横向PNP双极晶体管基区表面氧化层上制作了一栅电极,利用栅扫描法,通过扫描栅极所加电压,获得了基极电流随栅极电压的变化特性.理论推导和数学计算获得了氧化物陷阱电荷和界面陷阱电荷的定量变化,分离出栅控横向PNP双极晶体管在辐照及其室温退火过程中感生的缺陷.对设计的晶体管测试结构和采用的测试方法做了具体介绍.     

Feshbach resonance management of vector solitons in two-component Bose—Einstein condensates

We consider two coupled Gross-Pitaevskii equations describing a two-component Bose-Einstein condensate with time-dependent atomic interactions loaded in an external harmonic potential,and investigate the dynamics of vector solitons.By using a direct method,we construct a novel family of vector soliton solutions,which are the linear combination between dark and bright solitons in each component.Our results show that due to the superposition between dark and bright solitons,such vector solitons possess many novel and interesting properties.The dynamics of vector solitons can be controlled by the Feshbach resonance technique,and the vector solitons can keep the dynamic stability against the variation of the scattering length.     

质子辐射下互补金属氧化物半导体有源像素传感器暗信号退化机理研究

对某国产0.5 μm工艺制造的互补金属氧化物半导体有源像素传感器进行了10 MeV质子辐射试验, 当辐射注量达到预定注量点时, 采用离线的测试方法, 定量测试了器件暗信号的变化情况. 试验结果表明, 随着辐射注量的增加暗信号迅速增大. 采用MULASSIS (multi-layered shielding simulation software)软件计算了电离损伤剂量和位移损伤剂量, 在与γ辐射试验数据对比的基础上, 结合器件结构和工艺参数, 建立了分离质子辐射引起的电离效应和位移效应理论模型, 深入分析了器件暗信号的退化机理. 研究结果表明, 对该国产器件而言, 电离效应导致的表面暗信号和位移效应导致的体暗信号对整个器件暗信号退化的贡献大致相当.     

自旋为1/2的双层平方晶格阻挫模型的基态相变

基于线性自旋波理论,研究了二维各向异性双层平方晶格阻挫模型的基态性质.探讨了各向异性和自旋间交换作用对基态相图及系统可能发生相变的影响.结果显示:对于各向同性,当层间耦合相互作用J_c≥0.21或J_c≤-0.175时,Nèel态(NS)和Collinear态(CS)能共存;对于各向异性,NS和CS也可以共存.对弱的各向异性,NS更稳定;对于强的各向异性,系统将发生由NS向CS转换的一阶相变.     

大规模集成电路抗辐射性能无损筛选方法

空间辐射环境会对电子器件产生辐射损伤。由于商用器件性能普遍优于抗辐射加固器件,所以从商用器件中筛选出抗辐射性能优异的器件将在一定程度上提高空间电子系统的可靠性。结合数学回归分析与物理应力实验的方法,研究了集成电路抗辐射性能无损筛选技术。通过不同的外界能量注入及总剂量辐照实验,探究电路典型参数的应变情况与电路耐辐射性能的关系,并确定其辐射敏感参数;建立预测电路抗辐射性能的多元线性回归方程,并对应力条件下的回归方程进行辐照实验验证。结果显示,物理应力实验与数学回归分析结合的筛选方法减小了实验值与预测值的偏差,提高了预估方程的拟合优度和显著程度,使预估方程处于置信区间。     

基于X射线的晶圆级器件辐照与辐射效应参数提取设备的设计与实现

基于标准工艺线的设计加固是大规模集成电路抗辐射加固的发展趋势,对微纳米单元器件进行辐射效应参数提取是实现设计加固的前提。为了摒除参数提取过程中封装引入的影响,实现在线参数测试,本文设计了一套晶圆级器件辐照与辐射效应参数提取试验装置,兼备晶圆级器件电离总剂量辐照、器件参数在线测试分析功能,并且具有通用性强、测量范围宽、结构一体化、操作自动化等特点。对设备在50 kV管压下产生的X射线能谱、剂量率、束斑的测量以及对晶圆级MOS器件进行I-V、C-V、低频噪声特性的测试分析结果表明,该设备符合ASTM F1467测试标准,且能满足晶圆级器件辐射效应参数提取要求,可为大规模集成电路抗辐射设计加固提供良好的试验条件。     

CMOS有源像素图像传感器的电子辐照损伤效应研究

对某国产CMOS图像传感器进行了两种不同能量的电子辐照试验,在辐照前后及退火过程中采用离线测量方法,考察了暗信号、饱和电压、光谱响应特性等参数,分析了器件的电子辐照效应损伤机理。结果表明:暗信号和暗信号非均匀性都随着辐照剂量的增加及高温退火时间的延长而增大;饱和电压在两种能量电子辐照下均出现较大幅度的减小,并在高温退火过程中有所恢复;光谱响应特性无特别明显变化。经分析,暗电流、饱和电压的变化主要由辐照诱发的氧化物陷阱电荷导致的光敏二极管耗尽层展宽和界面陷阱电荷密度增大导致产生-复合中心的增加所引起。     

Radiation Effects Due to 3 MeV Proton Irradiations on Back-Side Illuminated CMOS Image Sensors

Benefitting from the higher quantum efficiency and sensitivity compared with the front-side illumination(FSI)CMOS image sensors(CISs), backside illumination(BSI) CMOS image sensors tend to replace CCDs and FSI CISs for space applications. However, the radiation damage effects and mechanisms of BSI CISs in the radiation environment are not well understood. We provide radiation effects due to 3MeV proton irradiations of BSI CISs dedicated to imaging by the analyses of mean dark current increase, dark current nonuniformity and full well capacity in pixel arrays and isolated photodiodes. Additionally, the present annealing certifies the radiationinduced defects, which are responsible for the parameter degradations in BSI CISs.     

Color ghost imaging via sparsity constraint and non-local self-similarity

We propose a color ghost imaging approach where the object is illuminated by three-color non-orthogonal random patterns. The object’s reflection/transmission information is received by only one single-pixel detector, and both the sparsity constraint and non-local self-similarity of the object are utilized in the image reconstruction process. Numerical simulation results demonstrate that the imaging quality can be obviously enhanced by ghost imaging via sparsity constraint and nonlocal self-similarity(GISCNL), compared with the reconstruction methods where only the object’s sparsity is used. Factors affecting the quality of GISCNL, such as the measurement number and the detection signal-to-noise ratio, are also studied.