Effective improvement of high-k Hf-silicate/silicon interface with thermal nitridation

The electrical properties of polysilicon gate MOS capacitors with hafnium silicate (HfSiO) dielectric, with and without NH/sub 3/ nitridation, were investigated. The results show that with NH/sub 3/ nitridation prior to deposition of HfSiO can effectively tune the flatband voltage close to that of conventional oxide and significantly improve the leakage properties over SiO/sub 2/ (three orders reduction). Furthermore, the excellent interface quality has been evidenced by the result of immunity against soft breakdown with NH/sub 3/ nitridation.     

Impedance boundary conditions in a hybrid FEM/MOM formulation

When numerically modeling structures with imperfect conductors or conductors coated with a dielectric material, impedance boundary conditions (IBCs) can substantially reduce the amount of computation required. This paper incorporates the IBC in the finite-element method (FEM) part of a FEM/method of moments (FEM/MoM) modeling code. Properties of the new formulation are investigated and the formulation is used to model three practical electromagnetic problems. Results are compared to either measured data or other numerical results. The effect of the IBC on the condition number of hybrid FEM/MoM matrices is also discussed.     

Double jeopardy in the nanoscale court [MOSFET modeling]

Physics-based compact short-channel models of threshold voltage and subthreshold swing for undoped symmetric double-gate MOSFETs are presented, developed from analytical solutions of the two-dimensional Poisson equations in the channel region. These models accurately characterize the subthreshold and near-threshold regions of operation by appropriately including essential phenomena such as volume inversion and the dominance of mobile charges over fixed charges under threshold conditions. Explicit, analytical expressions are derived for a scale length, which results from an evanescent-mode analysis. These equations readily quantify the impact of silicon film thickness and gate oxide thickness on the minimum channel length and device characteristics and can be used as an efficient guideline for device designs. These newly developed models are exploited to make a comprehensive projection on the scaling limits of undoped double-gate MOSFETs. On the individual device level, model predictions indicate that the minimum channel length can be scaled beyond 10 nm for a turn-off behavior of S=100 mV/dec for a silicon film thickness below 5 nm and an electrical equivalent oxide thickness below 1 nm.     

Grey-level image hiding scheme based on vector quantisation

A novel image hiding scheme capable of hiding multiple grey-level images into another grey-level cover image is proposed. To reduce the volume of secret images to be embedded, the vector quantisation scheme is employed to encode the secret images. The compressed message is then encrypted by the DES cryptosystem to ensure security. Finally, the encrypted message is hidden into the cover image using the greedy least significant bit substitution technique.     

LD抽运高功率连续波1.34 μmNd∶GdVO4激光器研究

报道了利用光纤耦合大功率半导体激光器 (LD)抽运Nd∶GdVO4晶体 ,采用平凹谐振腔 ,输出 1 34μm波长的高功率连续波固体激光器。在抽运功率为 1 4 75W时 ,获得最大输出功率为 4 6 2W ,光 光转换效率为 31 3% ,斜率效率达 32 9%。利用实验测得的阈值抽运功率和斜率效率 ,计算了Nd∶GdVO4晶体在 1 34μm波长处的受激发射截面     

光码分多址接入系统中远近效应的研究

对光码分多址接入系统中由于各个用户距离和发射功率不同导致的远近效应进行研究。结果表明 ,远近效应显著劣化了小功率用户的误码率和掉线率。而且 ,系统中用户的信号功率方差越大 ,各个用户的误码率和掉线率的劣化也越严重。提出了一种应用光硬限幅器消除远近效应的方法 ,该方法还极大地降低了多用户干扰     

碳纳米管电极上的电化学行为分析

用化学方法对碳纳米管进行表面处理 ,用红外谱对处理后的碳纳米管进行表征 ,处理后的碳纳米管表面出现了活性功能团羧基。用这些碳纳米管制成电极 ,对Cd离子在硫酸钠中的电化学行为进行了分析。结果表明 ,从碳纳米管电极上可以观察到很好的、准可逆循环伏安图 ;在扫描速度为 10 0mV·s- 1时 ,氧化还原峰电位分别出现在 - 0 .6 5V和 - 0 .95V对照饱和甘汞电极(SCE)。峰电流与扫描速度的平方根成良好的线性关系 ,说明反应过程是由镉离子的扩散控制的。由循环伏安图相关的电位与扫描速度关系 ,我们导出了电子转移动力学速度参数。由于碳纳米管电极有很好的电化学活性和可重复性 ,它可以成为一种新型的分析电极材料     

微机电安全密码锁的设计技术

微机电安全密码锁是一类用于确保“要害系统”安全性的装置 ,也可称为微锁、微型组合锁、微型密码鉴别器或微型使用控制开关。本文重点介绍了微机电安全密码锁的基本功能单元 :即鉴别器机构、驱动器与能量耦合器 ,结合工作原理的分析 ,探讨了装置总体设计中应考虑的关键问题     

大规模定制环境下 ERP 的发展

ERP─EnterpriseResourcePlanning企业资源计划系统 ,是指建立在信息技术基础上 ,以系统化的管理思想 ,为现代企业决策层及员工提供决策运行手段的管理平台。从竞争环境的角度出发 ,提出了大规模定制已经逐渐成熟并最终取代大规模生产成为新的生产经营模式的观点 ,同时 ,分析了在大规模定制下传统ERP的局限 ,从管理和技术的角度探讨新一代ERP的特点及发展。     

一种基于平移不变的小波阈值去噪算法

经典的D.L.Donoho小波阈值去噪算法在信号的奇异点处会产生Pseudo-Gibbs现象，从而使去噪后的信号在急剧变换部分产生振荡现象。为了抑制Pseudo-Gibbs现象，提出了一种基于平移不变的小波阈值去噪方法，在一定的平移量范围内，对分析信号进行循环平移，然后对这个新信号进行阈值处理，得到去噪后的信号，再对该信号作相反的循环平移，重复这一过程，对所获得结果求平均，就得到原始信号去噪后的估计信号。仿真实验的结果证明了算法的有效性。