共查询到20条相似文献,搜索用时 15 毫秒
1.
S. Pankalla R. Ganesan D. Spiehl H.M. Sauer E. Dörsam M. Glesner 《Organic Electronics》2013,14(2):676-681
We present a method for designing organic circuits using Monte-Carlo based circuit simulation. The organic devices suffer from mismatch and variations that are due to systematic and random fluctuations in the process and material characteristics. In this work, we have used the variable range hopping model to extract the model parameters using a mass characterisation technique. The parameter fluctuations of organic transistors are taken into account and process corners determined based on static (noise margin) and transient (delay) characteristics. Thus a methodology is developed to find the parameter range of individual devices, within which the circuits are having good performance, for instance inverters working with desired noise margin. We also found out the critical parameters of the transistor, that predominantly affects the static and transient performance of an inverter. These critical parameters can be provided as input to the process engineers to fine tune the process. This information can also be used in developing robust circuit design techniques, which can overcome the variation effects of these critical parameters. Thus, a mass characterisation of transistors combined with the proposed method, allows robust circuit design in the presence of huge process variations. 相似文献
2.
《Semiconductor Manufacturing, IEEE Transactions on》2009,22(2):217-224
3.
Boning D.S. Balakrishnan K. Hong Cai Drego N. Farahanchi A. Gettings K.M. Lim Daihyun Somani A. Taylor H. Truque D. Xie Xiaolin 《Semiconductor Manufacturing, IEEE Transactions on》2008,21(1):63-71
Variation afflicts the design, manufacture, and operation of integrated circuits. Techniques and tools are needed in three areas to address variation: statistical metrology, advanced process control, and design for manufacturability. First, statistical metrology seeks to characterize and model variations and their sources. Advanced metrology helps to understand geometric and material property variations, while variation test structures and test circuits enable study of the impact of specific or aggregate variations on performance. Second, advanced process control attempts to reduce process variation through sensing and feedback/feedforward control during fabrication. Third, design for manufacturability (DFM) seeks methods to improve performance and yield given process and environmental variation, through robust design, increased regularity, and other approaches. Finally, linkages between these areas, particularly between statistical metrology and DFM, will be important and empowering. 相似文献
4.
For future large-scale integration design technology, the device matrix array (DMA), which precisely evaluates within-die variation in device parameters, has been developed. The DMA consists of a 14-by-14 array of common units. The unit size is 240 by 240 /spl mu/m, and each unit contains 148 measurement elements (52 transistors, 30 capacitors, 51 resistors, and 15 ring oscillators). The element selection and precise measurement are achieved with low parasitic resistance measurement buses and leakage-controlled switching circuits, which allow the measurement accuracy for a transistor, resistor, or capacitor of 90 pA, 11 m/spl Omega/, and 23 aF, respectively, in the 3/spl sigma/ range. The ability to obtain 29 008 samples from a chip enables statistical analysis of the variation in 148 elements of each chip with 240-/spl mu/m spatial resolution. This high resolution and large sample number allows us to precisely decompose the data into systematic and random variation parts with newly developed fourth-order polynomial fitting. Our methodology has been verified using a test chip fabricated by a 130-nm CMOS process with a 100-nm physical gate length and five Cu interconnect layers. In MOSFETs, the random part was dominant and indicated a certain /spl sigma/ value in every chip. In the case of the interconnect layers, the random and systematic parts of the resistance and the capacitance indicated variance fluctuations. By chip, by item, by size, by structure, random or systematic, the /spl sigma/ values of each variation show inconsistency which we believe is attributable to the Cu process. The correlation coefficients of systematic part between device element and ring oscillator frequency shown very high value (0.87-0.98), and those of a random part were low enough (-0.10-0.22) to prove the accuracy of decomposition. 相似文献
5.
We present a new statistical technique for average power estimation in sequential circuits. Because of the feedback loops, power dissipations of sequential circuits in consecutive clock cycles are temporally correlated. The existence of data correlation makes it unsuitable to apply conventional techniques to average power inference, because the sample variance is no longer a maximum likelihood estimator. The convergence criterion derived from the biased variance estimation will be overly optimistic, causing power simulation to stop prematurely at a lower-than-specified estimation accuracy. To overcome this problem, we propose a systematic approach for modeling the power dissipation behavior of sequential circuits as an autoregressive random process. An accurate process variance can be obtained by the model parameters, which enables the derivation of a robust confidence interval of the average power. The interval is checked for convergence against a user-specified accuracy criterion. An iterative procedure is developed to invoke these steps repeatedly until the convergence specification is met. For a set of benchmark sequential circuits, this technique yields high accuracy and efficiency. 相似文献
6.
《Electron Devices, IEEE Transactions on》2006,53(9):2168-2178
The scaling of semiconductor technologies from 90- to 45-nm nodes highlights the need for accurate and predictive compact models that address the regime where small-scale physical effects become dominant. These demanding requirements on compact models extend beyond the core model to a suite of design tools that include extraction tools and statistical methods to account for unpredictable variation (e.g., random dopant fluctuations and polysilicon linewidth variation) and predictable variation (e.g., transistor response differences that are layout dependent). Layout-dependent or local environment differences are driven by factors such as lithography and novel performance-enhancing process techniques such as dual-stress nitride liner films. Sources of variation such as rapid thermal annealing temperature, low-frequency noise, and modeling of back-end-of-line elements need to be considered. The modeling of intradie and interdie variations, updated for small geometries, should be properly positioned in the design flow. This paper presents the challenges and results of compact modeling at the 65-nm node and beyond. 相似文献
7.
《Semiconductor Manufacturing, IEEE Transactions on》2009,22(2):245-255
8.
《Advanced Packaging, IEEE Transactions on》2009,32(2):237-247
9.
Today’s analog/RF design and verification face significant challenges due to circuit complexity, process variations and short
market windows. In particular, the influence of technology parameters on circuits, and the issues related to noise modeling
and verification still remain a priority for many applications. Noise could be due to unwanted interaction between the circuit
elements or it could be inherited from the circuit elements. In addition, manufacturing disparity influence the characteristic
behavior of the manufactured circuits. In this paper, we propose a methodology for modeling and verification of analog/RF
designs in the presence of noise and process variations. Our approach is based on modeling the designs using stochastic differential
equations (SDE) that will allow us to incorporate the statistical nature of noise. We also integrate the device variation
due to 0.18μ
m fabrication process in an SDE based simulation framework for monitoring properties of interest in order to quickly detect
errors. Our approach is illustrated on nonlinear Tunnel-Diode and a Colpitts oscillator circuits. 相似文献
10.
《Solid-State Circuits, IEEE Journal of》1984,19(6):948-956
Explicit formulas are derived using statistical methods for the random errors affecting capacitance and current ratios in MOS integrated circuits. They give the dependence of each error source on the physical dimensions, the standard deviations of the fabrication parameters, the bias conditions, etc. Experimental results, obtained for both matched capacitors and matched current sources using a 3.5-/spl mu/m NMOS technology, confirmed the theoretical predictions. Random effects represent the ultimate limitation on the achievable accuracy of switched-capacitor filters, D/A converters, and other MOS analog integrated circuits. The results indicate that a 9-bit matching accuracy can be obtained for capacitors and an 8-bit accuracy for MOS current sources without difficulty if the systematic error sources are reduced using proper design and layout techniques. 相似文献
11.
This paper reviews computer-aided design techniques to address mixed-signal coupling in integrated circuits, particularly wireless RF circuits. Mixed-signal coupling through the chip interconnects, substrate, and package is detrimental to wireless circuit performance as it can swamp out the small received signal prior to amplification or during the mixing process. Specialized simulation techniques for the analysis of periodic circuits in conjunction with semi-analytical methods for chip substrate modeling help analyze the impart of mixed-signal coupling mechanisms on such integrated circuits. Application of these computer-aided design techniques to real-life problems is illustrated with the help of a design example. Design techniques to mitigate mixed-signal coupling can be determined with the help of these modeling and analysis methods 相似文献
12.
A new direct method of computing the electromagnetic field patterns surrounding the conductor-backed coplanar waveguide (CPW) structure is proposed. Analytical closed-form expressions describing the quasi-TEM field pattern in both the air and the dielectric substrate for conductor-backed CPW's are presented. This approach is based on a new technique which employs a series of inverse conformal mappings to transform a known field pattern from a rectangular structure back into the CPW structure in order to obtain its unknown field pattern directly. A computer program based on this method has demonstrated the speed at which the fields can be plotted compared to existing methods which require repetitive application. Graphical results of these field patterns are presented as a function of the CPW's geometry and dielectric substrate thickness. These held maps which have been directly drawn with true curvilinear squares enable the determination of power flow density, since the same power flows through each square. This direct method of characterizing the power flow density throughout the CPW structure could become an important design tool for the modeling of coplanar monolithic microwave integrated circuits (CMMIC's) 相似文献
13.
Said Gaoua Shahrooz Asadi Mustapha C. E. Yagoub Farah A. Mohammadi 《Analog Integrated Circuits and Signal Processing》2010,63(1):59-70
In today’s radiofrequency and microwave communication circuits, there is an ever-increasing demand for higher integration
and miniaturization. This trend leads to massive computational tasks during simulation, optimization and statistical analyses,
requiring robust modeling tools so that the whole process can be achieved reliably. In this paper, the authors proposed frequency-
and time-domain computer-aided design tools that can characterize RF/microwave field effect and heterojunction bipolar transistors
and efficiently predict a circuit performance. The proposed tools are demonstrated through examples. 相似文献
14.
Robust minimum variance beamforming 总被引:16,自引:0,他引:16
This paper introduces an extension of minimum variance beamforming that explicitly takes into account variation or uncertainty in the array response. Sources of this uncertainty include imprecise knowledge of the angle of arrival and uncertainty in the array manifold. In our method, uncertainty in the array manifold is explicitly modeled via an ellipsoid that gives the possible values of the array for a particular look direction. We choose weights that minimize the total weighted power output of the array, subject to the constraint that the gain should exceed unity for all array responses in this ellipsoid. The robust weight selection process can be cast as a second-order cone program that can be solved efficiently using Lagrange multiplier techniques. If the ellipsoid reduces to a single point, the method coincides with Capon's method. We describe in detail several methods that can be used to derive an appropriate uncertainty ellipsoid for the array response. We form separate uncertainty ellipsoids for each component in the signal path (e.g., antenna, electronics) and then determine an aggregate uncertainty ellipsoid from these. We give new results for modeling the element-wise products of ellipsoids. We demonstrate the robust beamforming and the ellipsoidal modeling methods with several numerical examples. 相似文献
15.
Spatial filtering, particularly common in the field of engineering, is adapted in theory and practice to the filtering of propagating spatial EMG signals. This technique offers a new flexibility in the design of selective EMG measurement configurations. Longitudinal as well as two-dimensional spatial filters can be used. The conditions for the design of suitable spatial filters are deduced by signal theory. The performances of different selected configurations are compared by means of a given simple model of an excited motor unit. The modeling results compare well to the previously described experimental signals. 相似文献
16.
Tuna B. Tarim H. Hakan Kuntman Mohammed Ismail 《Analog Integrated Circuits and Signal Processing》2000,23(3):237-248
A robust design of low voltage low power square law CMOS composite cells using statistical VLSI design techniques is presented. Since random device/process variations do not scale down with feature size or supply voltage, the statistical design of low voltage circuits is essential in order to keep functional yields of low voltage circuits at levels that are competitive and cost effective. The Response Surface Methodology and Design of Experiment techniques were used as statistical techniques. This article shows that statistical techniques will result in area/layout optimization which will enhance functional yield of low voltage analog ICs. 相似文献
17.
数字图像空间分辨率改善的插值--模拟采样迭代方法 总被引:2,自引:0,他引:2
在遥感图像和计算机视觉的一些应用中,需要从已有的一些低分辨率图像来获得更高分辨率的图像.已有一些方法都是针对大小完全相同和图像之间不存在局部的几何畸变(或假设如此)的图像,而对从大小不同或分辨率不同的图像和图像之间存在相对的几何畸变等更普遍存在的实际图像来重构更高分辨率图像的问题未加涉及.本文用从带限信号的非均匀采样进行信号重构的迭代方法和凸集投影方法出发,导出了一种应用范围更加广泛的从多幅空间分辨率低的图像重构更高空间分辨率图像的一般性空间域插值-模拟采样迭代方法,并提出了凸集投影的变权迭代解法.该迭代方法可以对付图像之间存在相对的几何畸变、辐射亮度差异、空间分辨率差异及图像存在噪声等情形.实验表明,该迭代解法具有很好的收敛性和很好的收敛效果. 相似文献
18.
The testability of majority voting based fault-tolerant circuits is investigated and sufficient conditions for constructing circuits that are testable for all single and multiple stuck-at faults are established. The testability conditions apply to both combinational and sequential logic circuits and result in testable majority voting based fault-tolerant circuits without additional testability circuitry. Alternatively, the testability conditions facilitate the application of structured design for testability and Built-In Self-Test techniques to fault-tolerant circuits in a systematic manner. The complexity of the fault-tolerant circuit, when compared to the original circuit can significantly increase test pattern generation time when using traditional automatic test pattern generation software. Therefore, two test pattern generation algorithms are developed for detecting all single and multiple stuck-at faults in majority voting based circuits designed to satisfy the testability conditions. The algorithms are based on hierarchical test pattern generation using test patterns for the original, non-fault-tolerant circuit and structural knowledge of the majority voting based design. Efficiency is demonstrated in terms of test pattern generation time and cardinality of the resulting set of test patterns when compared to traditional automatic test pattern generation software. 相似文献
19.
This tutorial explains statistically designed experiments which provide a proactive means to improve reliability as advocated by Genichi Taguchi. That is, by systematic experimentation, the important parameters (factors) affecting reliability can be identified along with parameter values that yield reliability gains. In addition to improving reliability, Taguchi's robust design can be used to achieve robust reliability; that is, to make a process or product reliability insensitive to factors which are hard or impossible to control. Robust design is also implemented using statistically designed experiments. This paper presents classes of experimental plans for reliability improvement and robust reliability. An important feature of the reliability data collected from such experiments is censoring which occurs when some of the experimental units have not failed by the end of the experiment. Consequently, the analysis methodology must account for these censored data which are likely to occur in light of the ever increasing reliability of today's products. Several appropriate methods are discussed briefly. These experimental plans and analysis methods are illustrated using three documented experiments which improved fluorescent lamp and industrial thermostat reliability and which achieved robust reliability for night-vision goggles 相似文献
20.
《Electron Devices, IEEE Transactions on》1978,25(8):939-944
Yield on integrated circuits is the result of the contribution of many parameters including number of masking steps, design dimensions, and intrinsic process steps. Test vehicles specific to each process to be investigated are used and through ring oscillators yield figures, and test pattern results, evaluation of yield, as well as identification of main causes of yield loss can be made. The test vehicle approach is consistent with actual LSI circuits yield figures. Defect densities for SOS and bulk processes are compared showing that they are mainly dependent upon the number of critical masking steps and design dimensions. 相似文献