Stress Power Dependent Self-Heating Degradation of Metal-Induced Laterally Crystallized n-Type Polycrystalline Silicon Thin-Film Transistors

Using a fluorinated high-k/metal gate stack combined with a stress relieved preoxide (SRPO) pretreatment before high-k deposition, we show significant device reliability and performance improvements. This is a critical result since threshold voltage instability may be a fundamental problem, and performance degradation for high-fc is a concern. The novel fluorinated Ta_infinC_y/HfZrO_infin/SRPO gate stack device exceeds the positive-bias-temperature-instability and negative-bias-temperature-instability targets with sufficient margin and has electron mobility at 1 MV/cm comparable to the industrial high-quality polySi/SiON device on bulk silicon.     

Dual‐Activity Controlled Asymmetric Synthesis of Superconducting Lead Hemispheres**

A binary surfactant mixture of cetyltrimethylammonium bromide and polyvinyl pyrrolidone is used as the tailoring agent in the fabrication of lead micro/nanostructures. Electron microscopy studies indicate that the morphologies of the products can be efficiently controlled in this simple one‐step synthetic procedure. Intriguingly, well‐defined asymmetric functional colloids, Pb hemispheres, are obtained for the first time, and a dual‐activity‐controlled growth process is proposed to explain their formation. The magnetization measurements show that the as‐prepared samples are superconducting with the same transition temperature as bulk Pb. These findings prove the unique morphology tailoring efficacy of mixed surfactants, which could be used to obtain more variform structures or architectures in the fabrication of advanced materials.     

Fusion of digital television,broadband Internet and mobile communications—Part II: Future service scenarios

This is the second part of the tutorial paper following the previous tutorial paper describing enabling technologies in digital video broadcasting (DVB) system. The paper presents the current and future operational scenarios for DVB via satellite (DVB‐S) system. Review of the current state‐of‐the‐art technologies consisting of integration of broadband Internet and mobile communications and integration of broadband Internet and DVB are given. The future operational scenarios emphasize the fusion of DVB systems with other technologies in terms of network fusion and terminal fusion. For satellite service scenarios, it also takes into consideration mobility management and standard quality‐of‐service mechanism issues, such as integrated services and differentiated services. Several research directions for providing seamless services regardless of network, access technology and terminal in the fusion network are also highlighted in this paper. Copyright © 2007 John Wiley & Sons, Ltd.     

Power law behavior of magnetoresistance in tris(8-hydroxyquinolinato)aluminum-based organic light-emitting diodes

Long-term current drift and dielectric relaxation in organic thin films of a single-layer structure pose a serious problem for the accurate measurement of magnetoresistance at low magnetic fields. A new measurement scheme was devised to minimize errors and to report that the magnetoresistance in tris(8-hydroxyquinolinato)aluminum obeys a power law on the magnetic field at 300, 100, and 4.2 K in an entire range from 1 to 140 mT. The exponent of the power increases gradually from 0.47 for a bias voltage of 3 V to 0.58 for a bias voltage of 8 V. The magnetoresistance was observable above the threshold voltage only and its sign was always negative.     

Low power flexible organic thin film transistors with amorphous Ba0.7Sr0.3TiO3 gate dielectric grown by pulsed laser deposition at low temperature

We deposited amorphous Ba_0.7Sr_0.3TiO₃ (BST) on silicon and plastic substrate under 110 °C by pulsed laser deposition (PLD) and use it as the dielectric of the organic transistor. Depends on the thickness of BST layer, the highest mobility of the devices can achieve 1.24 cm² V^?1 s^?1 and 1.01 cm² V^?1 s^?1 on the silicon and polyethylene naphthalate (PEN) substrate, respectively. We also studied the upward and downward bending tests on the transistors and the dielectric thin films. We found that the BST dielectric pentacene transistor can maintain the mobility at 0.5 cm² V^?1 s^?1 or higher while the bending radius is around 3 mm in both upward and downward bending. Our finding demonstrates the potential application of PLD growth high-k dielectric in the large area organic electronics devices.     

感兴趣系数图像压缩编码算法

根据遥感图像编码的特殊性,提出了一种感兴趣系数编码算法。对于给定码率计算遥感图像小波域系数的熵估计值,从而大致确定正常编码情况下图像编码所截取到的比特平面, 在此基础上给出了感兴趣系数确定方案及提升幅度的计算方法。该算法与感兴趣区域编码方法不同,不需要在图像域指定感兴趣区域,系数提升幅度也不用提前指定,而且不必对所有子带的系数进行提升。该算法是任意区域的感兴趣区域编码的扩展和补充,但更为灵活、有效。仿真结果表明该算法可以有效保留遥感图像中小目标的信息,但图像总体质量略有下降。     

底部填充工艺的瞬时温度环境管理

微电子组装的大部份工艺开发都要求将元件做到更小,以便在尺寸日益缩小的便携式设备上实现更多功能。阐述了大元件的底部填充,即一侧的尺寸超过15mm,底部填充的胶量介于30～50mg。大尺寸晶元的制造工艺要求比现有生产线更大的产能,这就给底部填充点胶带来更大的挑战。大元件的产能超过3000个/h时,需要点胶机点出非常多的胶水。如此多的胶水在出胶前通过点胶阀,这将会带来加热的问题-某些工艺要求出胶前胶水必须要加热。这会对胶点尺寸有影响,因为随着温度的变化,底部填充的胶水黏度也会随之变化,从而轻微影响点出的胶量。从而将影响晶元相邻的“非沾染区”。稳定的温度是点胶稳定性的保证,并且能帮助胶水流进晶元下方同时也有助胶水分离从而更容易喷射出来。从研究中可以观察到：系统温度环境（点胶机内部）对点胶的胶水质量有影响。     

Interferential lithography of 1D thin metallic sinusoidal gratings: Accurate control of the profile for azimuthal angular dependent plasmonic effects and applications

Nonlinear processes involved in the manufacture of nominally sinusoidal surface relief diffraction gratings generated by interference lithography can introduce distortions into the profile of these surfaces. Such distortions may dramatically affect both the specular reflectivity and diffracted efficiencies from such a surface [H. Raether, Phys. Thin Film 9 (1977) 145–261]. We shall consider in particular the case of metallic gratings used to investigate plasmonic effects that can be engineered for bio-sensing applications. To investigate these effects, interference lithography (IL) has been used for the generation of profile controlled sinusoidal plasmonic crystals. IL exposure contrast study has been performed to control the amplitude oscillation and the surface roughness quality. Bi-metallic layer of silver and gold have been systematically deposited with different film thicknesses. A comprehensive numerical model that studies the optical coupling to surface plasmon polaritons on Ag/Au gratings has been undertaken for the simulation of the reflectivity and azimuthal angle dependence [Z. Chen, I.R. Hooper, J.R. Sambles, J. Opt. A: Pure Appl. Opt. 10 (1) (2008) 015007]. This computation illustrates the sensitivity of individual features to specific harmonic components of the surface, for surface plasmon resonances recorded in both the zeroth and higher diffracted orders. The roughness surface control after development and after bi-metallic evaporation strongly contributes to tighten the width of the reflectivity peak. Optimization process has shown that for an Ag (37 nm) and Au (7 nm) metallic bilayer, a semi-amplitude of 20 nm provides the best reflectivity.     

语音自动播放系统

介绍了语音自动播放系统的设计方法,通过采用89C52单片机控制语音芯片ISD4004、键盘、显示和存储部分等实现自动播放高清晰的语音记录,实现语音播放的可编程化、播放自动化,节省人力资源。     

含有受控源的线性电路的叠加原理研究

用叠加原理分析计算含有受控源的线性电路时,独立源可以单独作用,受控源是不能单独作用的。因为受控源单独作用只能求出与控制量有关的未知量,不能计算出具体值,具体值需要通过应用叠加原理才能计算出来,这是不符合叠加原理概念的。但是受控源单独作用作为一种计算方法还是可以的。