电子空穴对单电子陷阱存储器的设计与分析

本文论述了由Ti/TiOx/Ti介观隧道结阵列构成的电子空穴对耦合的单电子陷阱存储器,结合目前扫描隧道显微镜(STM)进行纳米加工的特点,设计了该存储器的电路结构及其结构参数,计算出电路的电容矩阵,并用Monte Carlo法对电路特性进行了模拟.结果表明,该存储器与其它单电子存储器有相同的存储特性,但具有较高的工作温度及工作稳定性.     

一种新型存储器件——磁电存储器

磁电存储器不仅存取速度快、功耗小，而且集动态RAM、磁盘存储和高速缓冲存储器功能于一身，因而已成为动态存储器研究领域的一个热点。文章总结了磁电存储器的工作原理和特性，分析了它们的发展现状及存在的问题，并对其应用前景进行了展望。     

MIM隧道发光结表面形貌分析

简介金属－绝缘层－金属（ＭＩＭ）隧道结的基本结构、工艺流程及发光机理。利用原子力显微镜（ＡＦＭ）观察ＭＩＭ隧道结的表面形貌，发现结表面存在规则有序的自然粗糙度。根据ＡＦＭ照片估计粗糙度尺寸，再利用小金属颗粒隧道结的偶极子共振发射天线理论，计算结发光光谱峰值，理论与实验符合较好。     

M-I-M隧道结发光器件的研究

金属-绝缘层-金属隧道结在低直流偏压下可发光。我们从三种结构研究了这种隧道结的发光效应,验证了表面粗糙度对隧道结的光辐射所起的显著作用,得出了快模式是光辐射的主要来源的初步设想。我们还在这种隧道结结构中引入了LB膜,构成了一种室温性能较好、很有前景的发光隧道结新结构。     

掩埋隧道结在长波长VCSEL结构中的应用

采用气态源分子束外延技术在InP(100）衬底上分别生长了δ掺杂的p+-AlIn-As-n+-InP和p+-InP-n+-InP两种隧道结结构，用电化学C-V和I-V特性曲线表征了载流子浓度和电学特性，发现p+-AlInAs-n+-InP隧道结性能优于p+-InP-n+-InP隧道结. 在InP(100）衬底上生长了包含p+-AlInAs-n+-InP掩埋隧道结和多量子阱有源层的1.3μm垂直腔面发射激光器（VCSEL）结构，测试得出其开启电压比普通的pin结VCSEL小，室温下其电致发光谱波长为1.29μm.     

MoS2势垒层磁性隧道结的温度-偏压特性研究

MoS₂是一种具有特殊能带结构的二维半导体材料,当层数较少时,其带隙会随层数显著减小。因此,基于MoS₂势垒层的磁性隧道结会展现出更丰富的物理特性。文章通过理论计算分别得到了单层、双层、三层以及五层MoS₂势垒层磁性隧道结的温度-偏压相图,研究了铁磁电极半交换劈裂能对相图特性的影响。计算结果表明：单层和三层MoS₂势垒层磁性隧道结适合应用于低温器件中。其中,单层MoS₂势垒层磁性隧道结在高功率工作环境下具有优异的性能。双层MoS₂势垒层磁性隧道结的优化区域位于室温和低偏压区,因此适用于信息存储领域。五层MoS₂势垒层磁性隧道结可通过调节铁磁电极参数使其工作在较宽的功率范围内。上述研究结果为MoS₂势垒层磁性隧道结的应用奠定了坚实的理论基础。     

电容耦合三结高温超导单电子晶体管数值模拟

基于单电子隧道效应的半经典模型，研究了电容耦合三结高温超导单电子晶体管的基本方程，分析了其I－V特性，并对两结和三结高温超导单电子晶体管的特性进行了比较。结果表明，单电子晶体管的特性与常规晶体管有很大的差别，且三结高温超导单电子晶体管比两结高温超导单电子晶体管有更高的灵敏度和更强的抗电磁干扰能力。     

高速高容量铁电存储器有望诞生

近日．复旦大学信息科学与工程学院微电子学系教授江安全在高密度铁电阻变存储器（Ferro—RRAM）的研究中取得重大进展，他带领的研究小组与中科院物理所、首尔大学、剑桥大学等合作，证明了一种铁电自发极化方向调制的P—n结电流，可运用于高密度信息的非挥发存储。这也就意味着，在存储器领域中，     

名词释义——分子存储器

分子存储器和现有的存储器的工作原理是一致的，区别在于电容的存储电荷方式。分子存储器的电荷是存储在分子中，而传统存储器的电荷是存储在氧化物上的体材料中。     

快闪存储器—存储器家族的新成员

磁盘和快闪存储器有一个共同的特点，即整块数据存储。计算机通常采用磁盘存储整块数据，而快闪存储器在数据存储方面更具有优越性。我们研究了快闪存储单元及其工作原理，从中了解到快闪存储器的特性以及与便携式计算机比较的结果。     

采用悬挂金属掩模制作约瑟夫逊隧道结

正 1.引言 近几年来由于约瑟夫逊隧道结在许多方面得到应用,特别是在新一代超级电子计算机上得到了应用,所以人们对制作小面积隧道结的技术产生了浓厚的兴趣。制作软金属超导隧道结,以IBM为代表已形成一套完整的工艺。但要用他们的办法重复地制作出实用的隧道结,必须有高级的专用设备和丰富的技术积累。一般单位在短期内是难以达到这样的技术水平的。1982年Gundlach(西德马克斯-普朗克学会)发表的文章仍在使用刀片制作的金属掩模。我们也曾经使用过这种掩模,但是用一般形式的金属掩模制作隧道结时,在氧化层势垒形成以后,必须打开镀膜机的钟罩,以便转换掩模制作上电极。这样氧化层势垒就容易受到大气污染。 为了克服这一缺点,我们用刀片拼装成的悬挂金属掩模来制作隧道结。这一技术具     

High temperature current–voltage characteristics of InP‐based tunnel junctions

In this paper, we present temperature‐dependent current–voltage measurements of tunnel junctions lattice matched to InP at temperatures ranging from room temperature to 220 °C. Temperature‐dependent tunneling properties were extracted by fitting the current–voltage characteristics using a simple analytical formula. Three different designs of tunnel junction were characterized, including a bulk InAlGaAs tunnel junction, an InAlGaAs tunnel junction with InAlAs cladding layers and an InGaAs/InAlGaAs quantum‐well tunnel junction. Each device exhibited different temperature dependence in peak tunnel current and excess current, with the quantum‐well tunnel junction exhibiting the greatest temperature sensitivity. We use a non‐local tunneling model, in conjunction with a numerical drift‐diffusion solver, to explain the performance improvement available by using double heterostructure cladding layers around the junction region, and use the same model to explain the observed temperature dependence of the devices. Copyright © 2014 John Wiley & Sons, Ltd.     

AlGaAs/GaAs tunnel junctions in a 4-J tandem solar cell

TheⅢ-Ⅴcompound tandem solar cell is a third-generation new style solar cell with ultra-high efficiency. The energy band gaps of the sub-cells in a GaInP/GaAs/InGaAs/Ge 4-J tandem solar cell are 1.8,1.4,1.0 and 0.7 eV,respectively.In order to match the currents between sub-cells,tunnel junctions are used to connect the sub-cells.The characteristics of the tunnel junction,the material used in the tunnel junction,the compensation of the tunnel junction to the overall cell’s characteristics,the tunnel junction’s influence on the current density of sub-cells and the efficiency increase are discussed in the paper.An AlGaAs/GaAs tunnel junction is selected to simulate the cell’s overall characteristics by PC1D,current densities of 16.02,17.12,17.75 and 17.45 mA/cm² are observed,with a V_oc of 3.246 V,the energy conversion efficiency under AM0 is 33.9%.     

Fabrication and numerical analysis of AlGaAs/GaAs tandem solarcells with tunnel interconnections

High-efficiency (20.2% at 1 sun, AM 1.5) Al_0.4Ga_0.6As/GaAs tandem solar cells are successfully fabricated by molecular-beam epitaxy. The interconnection between the AlGaAs top cell and the GaAs bottom cell consists of a GaAs tunnel junction sandwiched between AlGaAs layers and provides a high-quality tunnel junction. Numerical analysis suggests that an efficiency of 30% can be realized by increasing the carrier lifetimes of AlGaAs layers to 10^-8 s. An efficiency of 35% is expected to be obtainable by replacing the GaAs tunnel junction with an Al_0.33 Ga_0.67As tunnel junction     

Fabrication of Josephson tunnel junction with suspended metal mask

 A small area Josephson tunnel junction is fabricated with the suspended metal mask made of ordinary razor blades.The junction overlap is formed by two successive evaporations of superconductor materials at oblique angles.The advantages of this technique are that the fabrication processes can be performed continuously without opening the evaporation chamber and also it is suitable for making a small area tunnel junctions.The Ⅰ-Ⅴ characteristic of a tunnel junction made by this technique has been taken at 4.2K.     

四结叠层太阳电池中AlGaAs/GaAs隧穿结的特性和表现

III-V族化合物叠层太阳电池是具有超高转换效率的第三代新型太阳电池。四结叠层电池GaInP/GaAs/InGaAs/Ge,各子电池的带隙分别为1.8, 1.4, 1.0, 0.7(ev)。为了使各子电池之间电流匹配,在各子电池之间以隧穿结互相连接。本文主要探索研究了四结叠层电池GaInP/GaAs/InGaAs/Ge隧穿结的特性,三个隧穿结的材料选取,探讨了隧穿结对整体叠层电池的特性的补偿作用,对各子电池电流密度的影响,以及在此基础上对整体电池效率的增加。选用AlGaAs/GaAs作为隧穿结运用PC1D进行电池的整体模拟仿真,得到各子电池电流密度分别为16.02mA/cm²,17.12 mA/cm²,17.75 mA/cm²,17.45 mA/cm²,电池在AM0下的开路电压Voc为3.246V,转换效率为33.9%。     

A lateral metal—insulator—p-Si tunnel transistor

We report the fabrication of a lateral MIS tunnel transistor whose emitter and collector are Al/SiO2/p-Si tunnel junctions. All processing is carried out at room temperature except for the growth of the passivating field oxide. The small signal common emitter current gain is 20. Two coupled gain mechanisms exist for such a lateral MIS tunnel transistor. The first mechanism relies on a high minority-carrier injection ratio of the emitter junction. Second, the minority carriers injected into the reverse-biased collector junction may produce additional gain through multiplication of majority-carrier current. Lateral MIS tunnel transistors on n-Si make use of the second mechanism. Our device takes advantage of the high minority-carrier injection ratio achievable with Al/SiO2/p-Si tunnel junctions.     

An integrated controller for tunnel sensors

Micromachined tunnel sensors require electronic circuitry to servo control their tunnel gap width. In this paper, we present the first integrated and complete tunnel sensor controller. This self-contained CMOS controller provides all necessary controller functions; it generates a tunnel junction bias, senses the tunnel current by dropping it across a diode-connected transistor, compares the voltage across this diode to an internally generated proportional to-absolute-temperature reference, derives a feedback signal with an externally configurable frequency response, generates a high-voltage electrostatic drive, and provides a low-voltage output for external circuitry. The chip requires -5 and -40-V power supplies and a compensation RC network, consumes 0.9 mW power, has a power supply rejection ratio of 30 dB, and has a total die area, exclusive of bond pads, of 0.35 mm². The circuit compensates for tunnel junction nonlinearity and contributes less signal noise than the sensor that it controls     

The insulated gate tunnel junction triode

The gate modulated voltage breakdown of the drain diode in the MOS transistor is considered and shown to be direct electric field control of a reverse biased surfacep+-njunction. A structure designed to isolate this effect has been suggested by Atalla and experimentally evaluated by Nathanson, et al., and by the authors. The mechanism of operation discussed involves the application of an external electric field normal to the surface of the highly doped side of the junction to produce direct field emission of carriers. The reverse biased low doped side of the junction then acts as a collector of the field-emitted carriers resulting in a net current flow across the junction. Using the Atalla structure, a model is presented and a quantitative theory is developed to explain and predict the device performance. It is found that the actual device may be represented as an MOS transistor in series with an "ideal" field-controlled tunnel junction, and that the performance of the actual device can never be better than that of the limiting MOS transistor. The theoretical characteristics of the ideal field-controlled tunnel junction are derived and found to agree closely with the experimental results. It is shown that, at the present time, the device is limited by the "ideal" tunnel junction region and not by the series MOS transistor.