VLSI集成电路参数成品率及优化研究进展

VLSI的参数成品率是与制造成本和电路特性紧密相关的一个重要因素,随着集成电路(IC)进入超深亚微米发展阶段,芯片工作速度不断增加,集成度和复杂度提高,而工艺容差减小的速度跟不上这种变化,因此参数成品率的研究越来越重要.本文系统地讨论了参数成品率的模型和设计技术研究进展,分析不同技术的特点和局限性.最后提出了超深亚微米(VDSM)阶段参数成品率设计和成品率增强面临的主要问题及发展方向.     

一种基于非参数统计的微波集成电路成品率优化算法

给出了一种新的微波集成电路成品率优化算法——基于非参数统计的成品率快速优化算法。利用该方法，仅需要较少的仿真次数或直接利用非参数统计成品率分析算法的结果，便可直接得出一组或几组参数的成品率优化值，有效地缩短了优化时间。算例表明，该方法对微波集成电路进行快速成品率优化设计及提高电路设计的稳定性具有较好的应用价值。     

VLSI集成电路参数成品率及优化研究进展

VLSI的参数成品率是与制造成本和电路特性紧密相关的一个重要因素，随着集成电路(IC)进入超深亚微米发展阶段，芯片工作速度不断增加，集成度和复杂度提高，而工艺容差减小的速度跟不上这种变化，因此参数成品率的研究越来越重要．本文系统地讨论了参数成品率的模型和设计技术研究进展，分析不同技术的特点和局限性．最后提出了超深亚微米(VDSM)阶段参数成品率设计和成品率增强面临的主要问题及发展方向．     

统计DCTT最佳容差分配方法

本文提出了集成电路参数最佳容差分配的新模型和方法，该方法利用精确罚函数方法求解一类特殊的不可微量优化问题，它不仅可提供最佳容差分配结果，而且可为ＤＣＴＴ统计最优化提供满意的可行点，同时，这类方法可直接解决集成电路的泛函最优化问题，具有更进一步的拓展性。     

DCTT统计最优化模型及其性质

本文提出了集成电路最优化中综合考虑成品率极大、最佳容差设计、调整设计和生产效益极大化设计的统计最优化模型(Design Centering,Tolerance and Tuning.简称DCTT模型)。讨论了该模型与广义统计最优化模型的等价性以及其他主要性质。在确定性最优化框架下,该模型为统计最优化和集成电路可制造性设计的进一步发展开辟了新途径。     

基于缺陷均匀分布的集成电路制造成品率与可靠性之间的关系模型

在集成电路可制造性设计研究中,成品率与可靠性之间的关系模型备受人们关注.缺陷对成品率和可靠性的影响不仅与出现在芯片上的缺陷粒径大小有关而且与缺陷出现在芯片上的位置有关.本文主要考虑了出现在互连线上的金属丢失物缺陷对互连线的影响,分析了同一粒径的缺陷出现在互连线不同位置对互连线有效宽度的影响,给出了基于缺陷均匀分布的互连线平均有效宽度,结合已有成品率和可靠性估计模型,提出了基于缺陷位置信息的集成电路制造成品率与可靠性之间的关系模型.在工艺线稳定的情况下,利用该工艺线的制造成品率可以通过该关系式有效地估计出产品的可靠性,从而有效地缩短新产品的研发周期.     

基于工艺参数扰动的IC参数成品率多目标优化算法

在芯片制造工艺中,参数扰动影响了集成电路（Integrated Circuit,IC）成品率,使不同参数成品率间存在着此消彼长的相互制约关系,而目前IC参数成品率优化算法却主要局限于单一优化目标问题。本文提出一种基于工艺参数扰动的参数成品率多目标优化算法。该算法针对漏电功耗成品率及芯片时延成品率,首先构建具有随机相关性的漏电功耗及芯片时延统计模型;随后根据其相互制约特性建立基于切比雪夫仿射理论的参数成品率多目标优化模型;最后利用自适应加权求和得到分布均匀的帕雷托优化解。实验结果表明,该算法对于具有不同测试单元的实验电路均可求得大约30个分布均匀的帕雷托优化解,不仅能够有效权衡多个优化目标间的相互制约关系,还可以使传统加权求和优化方法在帕雷托曲线变化率较小之处得到优化解。     

集成电路可制造性设计理论与统计最优化方法统一模型的研究

文中系统地介绍了集成电路可制造性设计的基本概念，讨论了ＩＣ发展趋势和ＶＬＳＩ的极限，以及功能设计向优化设计过渡的必然性。综合考虑了电路制造的参数成品率极大，最佳容差设计，调整设计和制造费用极小化问题，提出了建立在不可微规划框架上的统计最优化方法的统一模型。     

随机掺杂波动引起阈值电压偏离的统计分析

工艺参数波动和偏离已严重影响纳米集成电路制造性能和成品率,阈值电压是MOS集成电路设计中的重要参数,而随机掺杂工艺波动是引起阈值电压的偏离的一个重要因素.本文根据阈值电压的偏离的物理机制,通过统计分析的方法,推导随机掺杂波动引起阈值电压偏离标准差的简洁表达式,根据该公式计算了实际纳米工艺器件阈值电压偏离的标准差数据,该...     

电路中心值最优化设计系统的研究与实现

本文提出一种容差域可伸缩的重心游移法来改进电路中心值设计的统计最优化方法＾［１］。该方法系统地解决了初始态下，成功点集为空集时的参数中心值设计问题。给出了容差域伸缩策略，并介绍了如何在ＳＰＩＣＥ软件基础上开发电路中心值优化系统的方法。     

步进频波形优化设计及处理技术

为增大步进频信号对多普勒效应的容忍度,文中对波形参数进行了优化设计。通过研究认为,对多普勒效应的容忍范围与脉冲重复周期之间存在强耦合关系,为增大容忍范围需要尽可能减小脉冲重复周期。为解决因减小重复周期而可能带来的距离模糊问题,提出了在频率上对发射端和接收端进行异步设置的处理技术,并且为了避免雷达作用范围内的盲区,提出了根据目标所在距离自适应设计信号波形参数的方法,此方法与处理技术特别适用于远程警戒雷达。     

Intelligent Robustness Insertion for Optimal Transient Error Tolerance Improvement in VLSI Circuits

Due to aggressive technology scaling, VLSI circuits are becoming increasingly susceptible to radiation-induced single-event-upsets (SEUs). Redundancy insertion has been adopted to provide the circuit with additional transient error resiliency. However, its applicability and efficiency are limited by the tight design constraints and budgets. In this paper, we present an intelligent “constraint-aware robustness insertion” methodology. By selectively protecting sequential elements in static CMOS digital circuits, it is able to maximally improve the SEU tolerance while keeping the incurred design overhead within acceptable range. Our technique consists of three major components. The first one is a configurable hardening sequential cell design that serves as the basic building block of the framework; the second one is a robustness calibration technique that evaluates the relative error tolerance of all sequential elements and provides guidelines to the redundancy insertion; the third one is an optimization algorithm that searches for the optimal protection scheme under given design constraints and budgets. Simulation results show that the intelligent robustness insertion reduced the error rate by 46% with zero timing penalty and 10% area increase. Furthermore, by exploring the tradeoffs between reliability and design overhead, we also demonstrate the proposed technique can help achieve high reliability improvement while keeping the design overhead within acceptable range.      

Design for testability of embedded integrated operationalamplifiers

The operational amplifier (op amp) is one of the most encountered analog building blocks. In this paper, the problem of testing an integrated op amp is treated. A new low-cost vectorless test solution, known as oscillation test, is investigated to test the op amp. During the test mode, the op amps are converted to a circuit that oscillates and the oscillation frequency is evaluated to monitor faults. The tolerance band of the oscillation frequency is determined using a Monte Carlo analysis taking into account the nominal tolerance of all important technology and design parameters. Faults in the op amps under test which cause the oscillation frequency to exit the tolerance band can therefore be detected. Some Design for Testability (DfT) rules to rearrange op amps to form oscillators are presented and the related practical problems and limitations are discussed. The oscillation frequency can be easily and precisely evaluated using pure digital circuitry. The simulation and practical implementation results confirm that the presented techniques ensure a high fault coverage with a low area overhead     

反射面天线误差设计研究

行为建模技术是一种利用模型参数控制其行为特性的闭环反馈设计系统。利用现代设计手段结合行为建模技术,设计人员可以在设计过程的任何时候评价设计结果。使用行为建模技术可以很好地解决反射面天线误差设计问题,通过单项分析各种可能存在的误差因素可获得相应的天线误差灵敏度,结合关联各方面误差的综合分析,可以为天线系统制造误差要求及分配提供解决依据。使用行为建模技术还能够解决天线变形等系统误差补偿问题,为天线调试与维护提供了一种直观有效的手段。     

最佳容差设计问题的研究正交内切球优化方法

本文提出最佳容差设计方法,该方法在设计中采用初始目标函数和准中心目标函数,使设计时间缩短;在优化中采用正交优化方法,使方法简单、直观;运用求可行域最大内切球半径和球心的方法,同时确定设计元件中心值和容差;为达到最佳设计之目的,本方法在最后进行一次中心值和容差的综合设计,本文给出例证,说明此方法可行,且有优越性。     

The design of radially symmetric lenses

For scanning over wide angles at millimeter wavelengths, an antenna incorporating a radially symmetric lens is an attractive solution if the lens can be realized in a practical form. It is shown that suitable lenses can be constructed very simply, from natural dielectrics if desired, and a design technique for the optimal antenna is presented. Some results are given of analytical and experimental studies of a number of actual antennas operating at wavelengths near 4 mm. These confirm that practical solutions are available. Homogeneous lenses may be used up to antenna gains of about 35 dB, and a lens consisting of a single shell and a core is sufficient for most other practical requirements.     

Practical Design of Lensed Fibers for Semiconductor Laser Packaging Using Laser Welding Technique

We propose a set of guidelines for the practical design of lensed fiber for the optical coupling of semiconductor lasers in butterfly packages using laser welding. These guidelines have optimized the tradeoff between coupling efficiency and alignment tolerance. Moreover, a radius of curvature of 11 $mu$m is shown to be optimal for semiconductor lasers whose divergence angles range from 5$^{circ}$ to 30$^{circ}$. To experimentally evaluate the design, lensed fibers were assembled by a Nd:YAG laser welding technique in conventional butterfly packages and their coupling efficiencies were 28%–72% without horizontal misalignment compensation.      

Packet-switch mechanism based on QoS class mapping using flow label for overlay network

In the past few years, overlay networks have emerged as an alternative option for supporting value-added services such as fault tolerance, multicasting, and security. In this paper, we describe a quality of service (QoS) overlay network architecture for scalable, efficient and practical QoS support. In this architecture, we propose a flow label (FL)-based QoS class mapping method for QoS implementation, which can offer better scalability for applications and provide users with more refined QoS. Based on this method, a packet-switch mechanism using flow label is presented, depending on which, packets can be transmitted fast according to label, and more optimal paths can be chosen to guarantee the QoS requirement.     

基于CPU-GPU协同并行内点算法求解结构化非线性规划

大量工程应用问题可建模为结构化非线性规划,且这类问题的系数矩阵可分为稀疏型和稠密型两种类型.利用原始-对偶内点法（primal dual interior point method,PD-IPM）,并结合分布式并行技术可高效求解此类问题.经典工程问题-机组组合（unit commitment,UC）为稀疏系数矩阵的结构化非线性规划,本文根据PD-IPM原理,对UC模型进行连续松弛预处理,结合快速解耦技术解耦牛顿修正方程并设计CPU-GPU协同并行算法求解子问题,最后将结果与带稠密型子问题的结构化非线性规划的求解结果进行比较和分析.实验结果显示,本文所设计的算法对于两种不同类型的结构化非线性规划求解均能获得较好的加速比.     

Design and Performance of Space–Time Precoder With Hybrid ARQ Transmission

Multiple-input-multiple-output (MIMO) technology can efficiently increase the system capacity in rich scattering environments without increasing the bandwidth or transmission power. The precoder for MIMO transmission is a processing technique that exploits the channel state information (CSI) by operating on the signal before transmission to effectively improve link performance. A hybrid automatic repeat request (HARQ) scheme can be incorporated with the linear precoder to ensure highly reliable communication. To fully utilize the type-I HARQ diversity gain, particularly in slow-fading channels, we propose the optimal design principle of linear precoders whose column vectors are correspondingly orthogonal to each other. In addition, the practical solution based on codebook is given in this paper. Finally, simulation results demonstrate the effectiveness of the proposed precoders in reducing the detection of bit error rate (BER) and in improving normalized throughput.