共查询到20条相似文献,搜索用时 46 毫秒
1.
Three-dimensional self-consistent simulation of silicon quantum-dotfloating-gate flash memory device
We report on the simulation of single-electron charging operation of a silicon quantum-dot memory device using the self-consistent solutions of the Schrodinger and Poisson equations. We focus on the effects of the poly-wrapped gate on the onset of inversion. We show that the geometry of the control gate causes the inversion to occur on the vertical sides of the channel. The device experiences a strongly nonuniform threshold voltage shift as a function of the number of electrons in the dot to reach about 0.5 V when the floating gate quantum-dot is charged from empty to ten electrons 相似文献
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Wei-Hsun Lin Chi-Che Tseng Kuang-Ping Chao Shu-Cheng Mai Shih-Yen Lin Meng-Chyi Wu 《Photonics Technology Letters, IEEE》2009,21(18):1332-1334
A ten-period InAs-GaAs quantum-dot infrared photodetector (QDIP) with 8-nm In0.15Ga0.85 As capping layer grown after quantum-dot (QD) deposition is investigated. With reduced InAs QD coverage down to 2.0 mono-layers, responses at 10.4 and 8.4 mum are observed for the device under positive and negative biases, respectively. The phenomenon is attributed to the large Stark effect resulted from the asymmetric band diagrams of the device under different voltage polarities. The demonstration of long-wavelength infrared detections with the simple structures of the InGaAs-capped QDIP is advantageous for the development of multicolor QDIP focal-plane arrays. 相似文献
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Stanislaw Kalicinski Martine Wevers Ingrid De Wolf 《Microelectronics Reliability》2008,48(8-9):1221-1226
This paper presents a first study concerned with charging and discharging phenomena in single crystal silicon MEM resonators. It is shown that the DC voltage required for the device operation induces a residual voltage between the resonator and its driving electrode, which is attributed to dielectric charging. The residual voltage can affect the device series resonance frequency and is determined from the measurements. The residual voltage maximum amplitude and the charging rate depend not only on the stressing voltage amplitude but also on the polarization. 相似文献
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Plasma-process-induced charging voltage for a device may be positive (gate is positive with respect to the substrate) or negative depending on the location of the device on the wafer. The negative charging damage increases the number of trapped holes closer to Si-SiO 2 interface while the positive charging damage does not. This number of trapped holes also depends on the antenna ratio. The trapped holes closer to the Si-SiO2 interface gets compensated by hot electrons injected during hot-carrier stressing. Thus, the type of charging voltage and the antenna size determines the hot-carrier response of a device. In addition, the differences in hot-carrier response for devices with varying antenna ratio are shown to be varying linearly with the differences in prestress subthreshold characteristics. This finding has the potential to reduce the hot-carrier stressing time or determine the most vulnerable devices without actually carrying out the experiments 相似文献
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为了改善现有CO2激光器工频LC谐振充电时充电电压随激光器工作频率升高而降低、影响激光输出的稳定性和光束质量,不利于装置的小型化和轻量化的问题。采用全桥逆变结构和串联谐振软开关电路,研究了36kV/10kW高频高压充电电源。该电源系统采用三相380V交流电作为供电系统,大功率智能功率模块作为全桥逆变电路。逆变交流信号经串联谐振电路及高频脉冲变压器得到高压脉冲信号,高压脉冲经整流给负载电容充电,电源应用电压电流双闭环控制系统,输出电压、电流经采样及放大后,反馈到电源控制芯片SG3525,芯片SG3525通过判断反馈信号的大小,控制输出脉冲宽度调制驱动信号的占空比。激光器放电频率为25Hz时,电源输出电压为37kV,峰值输出功率为13.05kW,充电效率为0.826。结果表明,该高频高压充电电源适合用作CO2激光器的高压充电电源。 相似文献
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Temperature study of the dielectric polarization effects of capacitive RF MEMS switches 总被引:2,自引:0,他引:2
Papaioannou G. Exarchos M.-N. Theonas V. Guoan Wang Papapolymerou J. 《Microwave Theory and Techniques》2005,53(11):3467-3473
This paper investigates both theoretically and experimentally the dielectric charging effects of capacitive RF microelectromechanical system switches with silicon nitride as dielectric layer. Dielectric charging caused by charge injection under voltage stress was observed. The amphoteric nature of traps and its effect on the switch operation were confirmed under both positive and negative control voltages. It has been confirmed that charging is a complicated process, which can be better described through the stretched exponential relaxation. This mechanism is thermally activated with an activation energy being calculated from the temperature dependence of the capacitance transient response. The charging mechanism, which is responsible for the pull-out voltage and the device failure, is also responsible for the temperature-induced shift of the capacitance minimum bias. 相似文献
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Jia-You Lee Yu-Ming Chang Fang-Yu Liu 《Industrial Electronics, IEEE Transactions on》1999,46(4):803-813
A new uninterruptible power supply (UPS) topology using the high-frequency tri-port UPS technique is proposed which presents the advantages of no-break power, low cost, input unity power factor, high power density, and high power conversion efficiency. Through the proposed circuit configuration, charging concept, and control strategy, the battery management is easily obtained by controlling the output voltage of the power-factor-correction (PFC) converter, which results in no additional power device being required for charging. The implementing circuit of the charging method is submitted to perform the two-stage charging, constant current charging, and constant voltage charging. The proposed technologies can be applied to the switching power supply with built-in UPS function featuring a low-cost solution for computer equipment, Finally, an experimental AC online UPS is built to verify the proposed concept, analysis, and control strategy 相似文献
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Gate oxide scaling effect on plasma charging damage is discussed for various IC fabrication processes such as metal etching, contact oxide etching, high current ion implantation, and via contact sputtering. Capacitance distortion, stress-induced leakage current, MOSFET characteristics, and circuit performance are used for evaluating the charging damage. We observed that very thin gate oxides are less susceptible to the charging damage because of their lower rate of interface damage, larger charge-to-breakdown, and less device determined stress voltage in the plasma system. We also discuss the diode protection scheme and design techniques for minimizing the charging damage. Latent damage exists after thermal annealing and can be revealed during the subsequent device operation causing circuit performance degradation. High density plasma etching is a trend of the etching technology as it provides better anisotropy, selectivity, and uniformity. Its effects on oxide charging damage is compared with low-density plasma etching. The resistance to process-induced charging damage of future devices appears to be high. This is counter-intuitive and is a good tiding for the future of IC manufacturing. The emergence of alternative gate dielectric raises questions about charging damage that requires further studies. 相似文献
10.
Horng-Chih Lin Chi-Chun Chen Chao-Hsing Chien Szu-Kang Hsein Meng-Fan Wang Tien-Sheng Chao Tiao-Yuan Huang Chun-Yen Chang 《Electron Device Letters, IEEE》1998,19(3):68-70
Monitoring of plasma charging damage in ultrathin oxides (e.g., <4 mm) is essential to understand its impact on device reliability. However, it is observed that the shift of several device parameters, including threshold voltage, transconductance, and subthreshold swing, are not sensitive to plasma charging and thus not suitable for this purpose. Consequently, some destructive methods, such as the charge-to-breakdown measurement, are necessary to evaluate plasma damage in the ultrathin oxides 相似文献
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基于AVR单片机的智能充电器的设计与实现 总被引:6,自引:0,他引:6
介绍了以AVR单片机为核心智能充电器的控制原理,讨论了充电器的硬件结构和软件设计思想.该充电器对充电过程进行全面管理,描述了充电检测的关键技术,实现了智能充电.并对充电电源、电压进行自动检测调整,充电后自动转为恒压浮充状态,使充电过程按理想的充电曲线进行,达到既保护电池、又能使电池充满的最佳效果等要求.这种全新的智能充电方式,有效地解决了普通充电器将蓄电池"充坏"的技术难题,大幅度提高了蓄电池的实际循环寿命,是电动自动车、电动汽车的理想产品. 相似文献
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A hybrid nanoparticle/organic device consisting of small molecule organic semiconductors and Ag nanoparticles is reported. The single device exhibits unusual properties of organic resonant tunneling diode (ORTD) at low driving voltage region and offers light emission at high voltage. For ORTD, a strong negative differential resistance behavior is demonstrated at room temperature. The current resonance with the peak‐to‐valley current ratio of over 4.6 and narrow linewidth of only ~1.4 V is achieved. A detailed operating mechanism of the charging and emission modes is proposed, which can be discussed in terms of the strong charge‐trapping effect of Ag nanoparticles. The repeatable operations of hybrid device show the mutual influences between two modes and the light emission properties of the ORTD are also discussed. 相似文献
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A semi-empirical analytic model for the threshold voltage instability of MOSFET is derived from the Shockley-Read-Hall (SRH) statistics in this paper to account for the transient charging effects in a MOSFET high-k gate stack. Starting from the single energy level and single trap assumption, an analytical expression of the filled trap density in terms of the dynamic time is derived from the SRH statistics. The semi-empirical analytic model of the threshold voltage instability is developed based on the MOSFET device physics between the threshold voltage and the induced trap density. The obtained model is also verified by the extensive experimental data of the trapping and de-trapping stress from the different high k gate configuration. 相似文献
18.
As conventional memories approach scaling limitations, new storage methods must be utilized to increase Si yield and produce higher on-chip memory density. Use of II–VI Zn0.56Cd0.44Se quantum dots (QDs) is compatible with epitaxial gate insulators such as ZnS-ZnMgS. Voltage-dependent charging effects in cladded Zn0.56Cd0.44Se QDs are presented in a conventional metal–oxide–semiconductor capacitor structure. Charge storage capabilities in Si and ZnMgS QDs have been reported by various researchers; this work is focused on II–VI material Zn0.56Cd0.44Se QDs nucleated using photoassisted microwave plasma metalorganic chemical vapor deposition. Using capacitance–voltage hysteresis characterization, the multistep charging and discharging capabilities of the QDs at room temperature are presented. Three charging states are presented within a 10 V charging voltage range. These characteristics exemplify discrete charge states in the QD layer, perfect for multibit, QD-functionalized high-density memory applications. Multiple charge states with low operating voltage provide device characteristics that can be used for multibit storage by allowing varying charges to be stored in a QD layer based on the applied “write” voltage. 相似文献
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It is found that a spurious leakage path from the emitter to the collector of a lateral p-n-p or a trench-defined n-p-n device may be induced by the applied collector voltage. This voltage influences the surface potential at the emitter-base junction through the charging of the polyimide used as interlevel dielectric or as trench fill, respectively. A simple model of the effect is developed, and several successful process features are discussed 相似文献
20.
X T Truong 《IEEE transactions on bio-medical engineering》1972,19(3):251-252
A device to produce displacement step pulses for studying viscoelastic wave propagation in biological specimens was developed on the basis of condenser discharge through a solenoid. The amplitude and rise time of the pulse step can be adjusted by varying the condenser capacity, charging voltage, and distance between the armature and the electromagnet. 相似文献