新型铁电存贮器和铁电薄膜的脉冲激光沉积

结合自己的工作，介绍了目前国际上新型功能材料与器件研究的热点之一－铁电集成和铁电存贮器的研究开发；报道了用脉冲激光沉积这种新型成膜技术制备铁电ＰＺＴ薄膜的些实验结果。     

利用猫式自泵浦位相共轭镜的光学联想存储器

报道了以快速响应（１５０ｍｓ），成像质量高（分辨率＞５０ｐｌ／ｍｍ）的１６°切掺铜钾钠铌酸锶钡（Ｃｕ：ＫＮＳＢＮ）晶体猫式自泵浦位相共轭境作为取阈反馈器件，以低吸收薄晶体Ｃｅ：Ｆｅ：ＬｉＮｂＯ３作为存储介质的光学全息联想存储器，利用２５％原信息寻址，可得出完整的联想输出．     

铁电存储器

许多国家在第二次世界大战期间就已经广泛地认识到,经久耐用的、化学上稳定的铁电晶体,将提供一种可作电开关双稳态器件,实现1和0态的编码操作.在美国和西欧的一些大的电子研究实验室,都已经从事这种器件的研制和开发工作.在50年代,铁电存储器的早期研制工作,一大部分集中在IBM、贝尔实验室、RCA和福特实验室. 目前在美国所使用的数字存储器的种类达14种之多,从用作数据库存储器的慢速但廉价的磁带或磁盘,直到快速但昂贵的静态随机存取存储器(SRAM)以及稍慢些的动态随机存取存储器(DRAM〕.当然,还有更加昂贵的器件,例如镀线存储器、带…     

双极双向联想存储器的单通道光学实现

以附加神经元引入附加背景的方式获得将线性离散比极神经元的神经网络在单通道光学矢量-矩阵乘法器内实现的方法,给出了相应的光学系统的修正和非负光学模板的编码形式.以双极神经元的双向联想存储器为例进行了计算机和光电实验模拟.     

纳米静态随机存储器低能质子单粒子翻转敏感性研究

针对65, 90, 250 nm三种不同特征尺寸的静态随机存储器基于国内和国外质子加速器试验平台, 获取了从低能到高能完整的质子单粒子翻转截面曲线. 试验结果表明, 对于纳米器件1 MeV以下低能质子所引起的单粒子翻转截面比高能质子单粒子翻转饱和截面最高可达3个数量级. 采用基于试验数据和器件信息相结合的方法, 构建了较为精确的复合灵敏体积几何结构模型, 在此基础上采用蒙特卡罗方法揭示了低能质子穿过多层金属布线层, 由于能量岐离使展宽能谱处于布拉格峰值的附近, 通过直接电离方式将能量集中沉积在灵敏体积内, 是导致单粒子翻转截面峰值的根本原因. 并针对某一轨道环境预估了低能质子对空间质子单粒子翻转率的贡献.     

A simple and accurate method for measuring program/erase speed in a memory capacitor structure

With the merits of a simple process and a short fabrication period, the capacitor structure provides a convenient way to evaluate memory characteristics of charge trap memory devices. However, the slow minority carrier generation in a capacitor often makes an underestimation of the program/erase speed. In this paper, illumination around a memory capacitor is proposed to enhance the generation of minority carriers so that an accurate measurement of the program/erase speed can be achieved. From the dependence of the inversion capacitance on frequency, a time constant is extracted to quantitatively characterize the formation of the inversion layer. Experimental results show that under a high enough illumination, this time constant is greatly reduced and the measured minority carrier-related program/erase speed is in agreement with the reported value in a transistor structure.     

Angular dependence of multiple-bit upset response in static random access memories under heavy ion irradiation

Experimental evidence is presented relevant to the angular dependences of multiple-bit upset (MBU) rates and patterns in static random access memories (SRAMs) under heavy ion irradiation. The single event upset (SEU) cross sections under tilted ion strikes are overestimated by 23.9% 84.6%, compared with under normally incident ion with the equivalent linear energy transfer (LET) value of ～ 41 MeV/(mg/cm 2 ), which can be partially explained by the fact that the MBU rate for tilted ions of 30 is 8.5%-9.8% higher than for normally incident ions. While at a lower LET of ～ 9.5 MeV/(mg/cm 2 ), no clear discrepancy is observed. Moreover, since the ion trajectories at normal and tilted incidences are different, the predominant double-bit upset (DBU) patterns measured are different in both conditions. Those differences depend on the LET values of heavy ions and devices under test. Thus, effective LET method should be used carefully in ground-based testing of single event effects (SEE) sensitivity, especially in MBU-sensitive devices.     

Modeling of conducting bridge evolution in bipolar vanadium oxide-based resistive switching memory

We investigate the resistive switching characteristics of a Cu/VOx/W structure. The VOx film is deposited by radio- frequency magnetron sputtering on the Cu electrode as a dielectric layer. The prepared VOx sample structure shows reproducible bipolar resistive switching characteristics with ultra-low switching voltage and good cycling endurance. A modified physical model is proposed to elucidate the typical switching behavior of the vanadium oxide-based resistive switching memory with a sudden resistance transition, and the self-saturation of reset current as a function of compliance current is observed in the test, which is attributed to the conducting mechanism is discussed in detail. growth pattern of the conducting filaments. Additionally, the related     

微纳尺度热能调控的声子学元器件研究进展

声子是半导体材料中热能的主要载体.通过对声子调控的深入研究,人们可以为微纳电子器件散热和热能转换提供有效的解决方案.文章介绍了热能调控声子学元器件的研究进展,重点阐述了理论上如何利用微纳米结构材料构建声子学基本单元——热二极管/热整流器.此外,文章还介绍了该领域的关键测量技术和实验进展,包括热整流器和热存储器的设计与实现.最后对声子学研究的发展趋势进行了展望,并提出了存在的困难和挑战.     

阻变存储器复合材料界面及电极性质研究

采用基于密度泛函理论的第一性原理对比研究了Cu（111）/HfO₂（001）,Cu（111）/HfO₂（010）,Cu（111）/HfO₂（100）三种复合材料界面模型的失配率、界面束缚能、电荷密度、电子局域函数以及差分电荷密度. 计算结果表明：Cu（111）/HfO₂（010）失配率最小,界面束缚能最大,界面体系相对最稳定;对比电荷密度及电子局域函数图显示,只有HfO₂（010）方向形成的复合材料体系出现了垂直Cu电极方向完整连通的电子通道,表明电子在此方向上具有局域性、连通性,与阻变存储器（RRAM）器件导通方向一致;差分电荷密度图显示,Cu（111）/HfO₂（010）复合材料体系界面处存在电荷密度分布重叠的现象,界面处有电子的相互转移、成键的存在;进一步计算了Cu（111）/HfO₂（010）体系距离界面不同位置的间隙Cu原子形成能,表明越靠近界面Cu原子越容易进入HfO₂ 体内,在外加电压下易发生电化学反应,从而导致Cu导电细丝的形成与断裂. 研究结果可为RRAM存储器的制备及性能的提高提供理论指导和设计工具. 关键词： 阻变存储器 复合材料 界面 电子通道