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1.
采用分子束外延方法在砷化镓衬底上生长了双垒单阱结构,然后用常规半导体器件工艺制成了谐振隧穿二极管(RTD),有相当好的I-V特性.对于5μm×5μm的RTD器件,在室温条件下,测得其峰谷比最大可到7.6∶1,最高振荡频率大于26GHz.  相似文献   

2.
在半绝缘的50nm InP衬底上采用分子束外延的方法生长了RTD与HEMT的集成材料结构.RTD室温下峰谷电流比最高达到18.39,阻性截止频率大于20.05GHz.栅长为1μm的HEMT截止频率为19.8GHz,最大跨导为237mS/mm.由多个RTD串联形成的多峰值逻辑以及HEMT栅压调节RTD电流的特性也得以验证.  相似文献   

3.
在半绝缘的50nm InP衬底上采用分子束外延的方法生长了RTD与HEMT的集成材料结构.RTD室温下峰谷电流比最高达到18.39,阻性截止频率大于20.05GHz.栅长为1μm的HEMT截止频率为19.8GHz,最大跨导为237mS/mm.由多个RTD串联形成的多峰值逻辑以及HEMT栅压调节RTD电流的特性也得以验证.  相似文献   

4.
在InP衬底上采用感应耦合等离子体刻蚀技术制备了高性能的AlAs/In0.53Ga0.47As/InAs共振隧穿二极管.正向偏压下PVCR=7.57,Jp=39.08kA/cm2;反向偏压下PVCR=7.93,Jp=34.56kA/cm2.在未去除测试电极和引线等寄生参数影响下,面积为5μm×5μm的RTD的阻性截止频率为18.75GHz.最后对非对称的I-V特性进行了分析讨论.  相似文献   

5.
在InP衬底上采用感应耦合等离子体刻蚀技术制备了高性能的AlAs/In0.53Ga0.47As/InAs共振隧穿二极管.正向偏压下PVCR=7.57,Jp=39.08kA/cm2;反向偏压下PVCR=7.93,Jp=34.56kA/cm2.在未去除测试电极和引线等寄生参数影响下,面积为5μm×5μm的RTD的阻性截止频率为18.75GHz.最后对非对称的I-V特性进行了分析讨论.  相似文献   

6.
报道了GaAs基共振隧穿二极管(RTD)与金属-半导体-金属光电探测器(MSM PD)单片集成的两种光电集成电路,并在室温条件下分别测试了RTD器件、MSM器件和集成电路的电学特性.测试表明:RTD器件的峰谷电流比为4;由于改进了在半绝缘GaAs衬底上制作MSM的方法,5V偏压下的电流由原来的2μA增加到了18μA,基本实现了两种电路的逻辑功能.  相似文献   

7.
介绍了一种基于共振隧穿二极管(RTD)和高电子迁移率晶体管(HEMT)的单片集成电路.采用分子束外延技术在GaAs底层上重叠生长了RTD和HEMT结构.RTD室温下的峰谷电流比为5.2∶1,峰值电流密度为22.5kA/cm2.HEMT采用1μm栅长,阈值电压为-1V.设计电路称为单稳态-双稳态转换逻辑单元(MOBILE).实验结果显示了该电路逻辑运行成功,运行频率可达2GHz以上.  相似文献   

8.
介绍了一种基于共振隧穿二极管(RTD)和高电子迁移率晶体管(HEMT)的单片集成电路.采用分子束外延技术在GaAs底层上重叠生长了RTD和HEMT结构.RTD室温下的峰谷电流比为5.2∶1,峰值电流密度为22.5kA/cm2.HEMT采用1μm栅长,阈值电压为-1V.设计电路称为单稳态-双稳态转换逻辑单元(MOBILE).实验结果显示了该电路逻辑运行成功,运行频率可达2GHz以上.  相似文献   

9.
报道了GaAs基共振隧穿二极管(RTD)与金属-半导体-金属光电探测器(MSM PD)单片集成的两种光电集成电路,并在室温条件下分别测试了RTD器件、MSM器件和集成电路的电学特性.测试表明:RTD器件的峰谷电流比为4;由于改进了在半绝缘GaAs衬底上制作MSM的方法,5V偏压下的电流由原来的2μA增加到了18μA,基本实现了两种电路的逻辑功能.  相似文献   

10.
谐振隧穿二极管的直流模型及其双稳态特性   总被引:4,自引:1,他引:3  
研制成的在常温下工作的谐振隧穿二极管 (RTD) ,峰谷比达到了 5∶ 1,最高振荡频率为 2 6 .3GHz.采用基于物理意义的电流 -电压方程 ,利用通用电路模拟软件 PSPICE,建立了其直流电路模型 ,模拟结果和实验数据吻合得很好 ;并以此为基础模拟出了以 RTD为驱动器 ,以电阻或 RTD本身为负载的电路双稳态特性 ,同时分析了 RTD器件双稳态特性 .  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

15.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

16.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

17.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

18.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

19.
We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.  相似文献   

20.
To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.  相似文献   

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