SOC布图设计中的互连优化算法

使用Elmore时延模型,对二端连线的缓冲器插入方法进行了详细的讨论.给出了最小时延下,缓冲器的最佳数量和位置;同时给出了在一定时延约束条件下的缓冲器的最小数量及位置;并在典型的0.18μm工艺参数条件下进行了测试.测试结果显示,缓冲器插入方法可以显著地减小线上的时延,而且缓冲器的数目将随着时延约束的放宽而迅速下降.当时延约束仅比最优时延多5%时,插入的缓冲器数目就降到了最佳缓冲器数的70%左右,这一结果对缓冲器插入算法具有普遍的指导意义.     

精确时延模型下满足时延约束的缓冲器数目最小化的算法

提出了在精确时延模型下,满足时延约束的缓冲器数目最小化的算法.给出一个两端线网,该算法可以求出满足时延约束的最小缓冲器数目.运用高阶时延模型计算互连线的时延,运用基于查找表的非线性时延模型计算缓冲器的时延.实验结果证明此算法有效地优化了缓冲器插入数目和线网的时延,在二者之间取得了较好的折中.算法的运行时间也是令人满意的.     

精确时延模型下满足时延约束的缓冲器数目最小化的算法

提出了在精确时延模型下,满足时延约束的缓冲器数目最小化的算法.给出一个两端线网,该算法可以求出满足时延约束的最小缓冲器数目.运用高阶时延模型计算互连线的时延,运用基于查找表的非线性时延模型计算缓冲器的时延.实验结果证明此算法有效地优化了缓冲器插入数目和线网的时延,在二者之间取得了较好的折中.算法的运行时间也是令人满意的     

受摆率约束的缓冲器插入设计优化方法

随着VLSI集成度的提高,缓冲器插入技术作为一种互连优化方法,在系统设计中得到了广泛的应用。提出一种针对片上互连网络的缓冲器插入方法,求解在摆率约束下的缓冲器最优插入问题。该方法由两阶段算法组成,首先对待优化互连线网进行分段,以求解可行的缓冲器插入位置集合,其次在所求得的上述位置集合中求解摆率约束条件下的最小代价缓冲器插入问题。在0.13 μm CMOS工艺下进行电路设计,实验结果表明,相较于延时最优缓冲器插入方法,该方法所得优化结果能够满足实际电路的摆率约束,同时获得最小超过30%的面积改善比率。     

基于精确时延模型考虑缓冲器插入的互连线优化算法

随着VLSI电路集成度增大和特征尺寸的不断减小,连线的寄生效应不可忽略,互连线的时延在电路总时延中占了很大的比例,成为决定电路性能的主要因素.在互连时延的优化技术中,缓冲器插入是最有效的减小连线时延的方法.本文提出了一个在精确时延模型下,在布线区域内给定一些可行的缓冲器插入位置,对两端线网进行拓扑优化,并同时插入缓冲器以优化时延的多项式时间实现内的算法.我们的算法不但可以实现时延的最小化,也可以在满足时延约束的条件下,最小化缓冲器的插入数目,从而避免不必要的面积和功耗的浪费.     

采用精确时延模型基于路径的缓冲器插入时延优化

提出了一种基于路径的缓冲器插入时延优化算法 ,算法采用高阶模型估计连线时延 ,用基于查表的非线性时延模型估计门延迟 .在基于路径的时延分析基础上 ,提出了缓冲器插入的时延优化启发式算法 .工业测试实例实验表明 ,该算法能够有效地优化电路时延 ,满足时延约束     

采用精确时延模型基于路径的缓冲器插入时延优化

提出了一种基于路径的缓冲器插入时延优化算法,算法采用高阶模型估计连线时延,用基于查表的非线性时延模型估计门延迟.在基于路径的时延分析基础上,提出了缓冲器插入的时延优化启发式算法.工业测试实例实验表明,该算法能够有效地优化电路时延,满足时延约束.     

一种提高芯片良率的时序电路缓冲器插入算法

针对集成电路工艺参数波动影响芯片良率的问题,提出一种提高芯片良率的时序电路缓冲器插入算法.该算法通过蒙特卡罗仿真模拟流片后的芯片,确定时序电路中可插入缓冲器的最佳位置,在保证良率的前提下,降低了面积及成本损耗.算法经过ISCAS89的基准电路和TAU2013的电路进行仿真验证,结果表明插入缓冲器的数量小于等于触发器数量的1%,良率提高高达35.98%.     

时钟延时及偏差最小化的缓冲器插入新算法

本文提出了以最小时钟延时和时钟偏差为目标的缓冲器插入新算法.基于Elmore延时模型,我们得到相邻缓冲器间的延时是缓冲器在时钟树中位置的凸函数.当缓冲器布局使所有缓冲器间延时函数具有相同导数值时,时钟延时达到最小;当所有源到各接收端点路径的延时函数值相等时,时钟偏差达到最小.对一棵给定的时钟树,我们在所有从源点到各接收端点路径上插入相同层数的缓冲器,通过优化缓冲器的位置实现时钟延时最小;通过调整缓冲器尺寸和增加缓冲器层数,实现时钟偏差最小.     

VLSI互联线的延时优化研究

首先对互连线模型进行了分析,介绍了插入缓冲器来减小长线延时的方法,然后通过具体计算分析了缓冲器插入的位置、数量,以及尺寸对连线延迟的影响,得出了理论上最理想的优化方案,并给出了结合实际物理设计的优化方案和算法.最后,对一条长互联线的延迟进行了仿真计算,结果证明所给出的算法可有效地减小延时.     

Development of the readout system for waveguide multilayer optical card

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.