Air-Gap Transmission Lines on Organic Substrates for Low-Loss Interconnects

The fabrication of low-loss transmission line structures with an air dielectric layer is described. The channels are characterized at low frequency (10 and 100 kHz) using capacitance and loss tangent and at high frequency (500 MHz to 10 GHz) using -parameter measurements. The incorporation of an air gap resulted in structures with effective dielectric constants between 1.5-1.8 and significantly lower loss tangents. The fabrication technique could be used to create more complicated air gap transmission line structures for use in monolithic microwave integrated circuits.     

Systematic Lumped-Element Modeling of Differential IC Transmission Lines

In this paper, we report a systematic and efficient approach to obtain lumped-element models for differential integrated-circuit interconnect transmission lines covering both the low-frequency R/C as well as the high-frequency quasi-TEM behavior. To accurately model signal delay and loss, and to preserve causality, the frequency dependence of both line resistance as well as the line inductance is included in our model. The impact of ground inductance is also properly covered by the model. The validity of our approach is verified against experimental data collected up to 120 GHz for the even and odd modes on these differential transmission lines. We predict that these lines can transport data over 1-cm distance with rates up to 40 Gb/s, even with some imbalance in differential drive.      

集成电路Cu互连线的XRD研究

对硫酸盐体系中电镀得到的Cu镀层,使用XBD研究不同电沉积条件、不同衬底和不同厚度镀层的织构情况和择优取向.对比了直流电镀和脉冲电镀在有添加剂和无添加剂条件下的织构情况.实验结果表明,对于在各种条件下获得的1 μm Cu镀层,均呈现(111)晶面择优,这样的镀层在集成电路Cu互连线中有较好的抗电迁移性能.     

集成电路互连引线电迁移的研究进展

随着大规模集成电路的不断发展,电迁移引起的集成电路可靠性问题日益凸现.本文介绍了电迁移的基本理论,综述了集成电路互连引线电迁移的研究进展.研究表明,互连引线的尺寸、形状和微观组织结构对电迁移有重要影响;温度、电流密度、应力梯度、合金元素及工作电流模式等也对电迁移寿命有重要影响.同时指出了电迁移研究亟待解决的问题.     

RLC传输线的精确矩模型及其在互连线网时延估计中的应用

快速估计互连线网的信号传输特性是VLSI设计中的重要问题,矩匹配是目前的主要方法.本文给出了获得RLC传输线精确矩模型的一个简单方法,避免了以往方法复杂的推导.文中还提出了互连线时延估计的一个新方法,这一方法不仅可用于目前通常的二阶模型,还可对高阶模型进行估计.     

Simulation of Critical IC Fabrication Processes Using Advanced Physical and Numerical Methods

Critical steps of IC fabrication are simulated by one- and two-dimensional computer programs using advanced physical models. Our codes deal with an arbitrary number of physical quantities such as concentrations of dopants, vacancies, interstitial and clusters, the electrostatic potential, and so on. Furthermore, they easily permit the exchange or variation of the physical models under consideration. As typical applications phenomena of coupled diffusion in one and two dimensions and dynamic arsenic clustering are investigated. The differences caused by the models of the zero space-charge approximation and the solution of the exact Poisson equation are studied by examples of As-B diffusion with various doping concentrations at different temperatures. A dynamic cluster model developed for the simulation of thermally annealed As implantations is compared to measured data of laser annealing experiments. A short outline of the mathematical and the numerical problems is given to show the amount of sophistication necessary for up-to-date process simulation.     

深亚微米集成电路设计中的互连线延迟问题

深亚微米集成电路的互连线延迟是设计中需十分重视并必须解决的问题。本文讨论了影响互连线延迟的因素并对深亚微米物理设计的关键步骤中如何考虑并解决互连线延迟问题进行叙述和讨论。     

中国集成电路多层布线工艺技术的实践及发展方向

本文结合我公司双层布线工艺技术的自我实践及我公司与日本富士通公司技术合作的成果，再引用当今世界上最先进的CMP多层布线技术，来阐述我国集成电路双层布线技术的实践及发展方向。     

铜互连布线及其镶嵌技术在深亚微米IC工艺中的应用

近几年来 ,随着 VLSI器件密度的增加和特征尺寸的减小 ,铜互连布线技术作为减小互连延迟的有效技术 ,受到人们的广泛关注。文中介绍了基本的铜互连布线技术 ,包括单、双镶嵌工艺 ,CMP工艺 ,低介电常数材料和阻挡层材料 ,及铜互连布线的可靠性问题     

集成电路铜互连线脉冲电镀研究

针对先进纳米铜互连技术的要求,研究了脉冲电流密度对铜互连线电阻率、晶粒尺寸和表面粗糙度等性能的影响.实验结果表明,2～4 A/dm2电流密度下的铜镀层拥有较小电阻率、较小的表面粗糙度和较大的晶粒尺寸.     

The Analysis and Identification of Flux-Induced Voltage Transients on Low-Loss Transmission Lines with Application to the Lightning-Transient-Analysis (LTA) Problem

One of the acknowledged lightning threats to aircraft is the induction threat in which a lightning-induced fuselage skin current inductively or capacitively flux couples through small dielectric "holes" or apertures in the fuselage onto intemal avionics cabling. In order to optimize the circuit protection, it is necessary to identify both the nature and location of the flux excitation. Using standard capacitor-bank LTA testing, this paper advances a linear-system-identification technique, based on the impulse response, that will defme both the nature and location of the dominant excitations. The technique is then successfuily applied to the identification of the Yaw Damper Circuit of the USAF F-111.     

Minimization of Via-Induced Signal Reflection in On-Chip High Speed Interconnect Lines

Vias are extensively used to connect different metal levels in a multilayered Integrated Circuits (IC). The impedance discontinuities at the junction of the interconnect and via results in signal reflections and create signal integrity problems. This is one of the important design issues in ICs operating at gigahertz (GHz) frequencies. In this paper, a method for the reduction of via-induced signal reflection in high-speed on-chip intermediate/global interconnect structures is proposed. Signal reflection minimization is achieved through impedance matching by the inclusion of an appropriate capacitive load at the interconnect–via junction. This method is demonstrated for a two-layer interconnect structure connected through a via. The proposed solution reduces the signal reflection to as low as −35 dB at the tuned frequency of 5 GHz and less than −10 dB in its vicinity (1 to 10 GHz). The operating frequency can be changed by tuning the matching capacitive load and hence this method can be extended to any high frequency operation by digitally tuning a bank of on-chip capacitors (without going through a new fabrication run). Further it is shown that the signal reflections are reduced considerably in a six-layer structure and hence this method can be extended to any multi-level interconnect structure.     

Problems in Strip Transmission Lines

A review is given of characteristic-impedance formulas for shielded-strip transmission lines. From these formulas a set of approximate relationships for the attenuation and Q of a dielectric-filled shielded-strip transmission line is derived. The method makes the standard assumption that the current distribution is that of a lossless line and the surface resistivity that of an infinite-plane condutor. Although this method applies accurately to most other types of lines, in this case an error of the order of 10% is believed to occur due to the failure of the assumptions at the corners of the strip. However, the error is in a direction that makes the computed values conservative, and the accuracy should be sufficient for most practical purposes. The derivation of a correction term is now being attempted. In addition to the discussion of attenuation attention is given in this paper to the design considerations involved in a shielded-strip-line impedance meter, and to some preliminary data obtained with this device. Also the future topics for investigation under this research and development program are mentioned.     

Analysis of Arbitrarily Oriented Microstrip Transmission Lines in Arbitrarily Shaped Dielectric Media Over a Finite Ground Plane

A numerical analysis is presented for a multiconductor transmission line in multilayered Iossy, dielectric regions where the ground plane is of finite extent. The transmission fines are infinitely long and vary in cross section from finite to infinitesimally thin. The Green's function for such a two-dimensional transmission line involves an arbitrary constant. If the ground plane is infinite, the method of images could be used where this constant cancels out. However, in the case of a finite ground plane, the constant has to be evaluated. Here a numerical method is presented where the constant could be eliminated rather than evaluated by imposing the condition for the total charge to be zero. The transmission lines, dielectric regions, and the ground plane can have arbitrary cross sections.     

Low-Loss Slow Light Transmission in Photonic Crystal Waveguides Comprising of Liquid Crystal Infiltration

A low loss photonic crystal(PhC) waveguide having rectangular air holes in Si core is proposed having an average group index of 55 in the bandwidth of 1.2 THz.The possible propagation losses due to inefficient coupling are also investigated for proposed structure.It is found that high transmission is obtained for a broad bandwidth from the output of the finally designed heterogeneous waveguide consisting of a slow liquid crystal infiltrated PhC waveguide surrounded by fast PhC waveguides on both sides.     

Anomalous Low-Loss Transmission in a Gas-Confined Dielectric Waveguide for Millimeter and Submillimeter Wavelengths

A novel low-loss (gas-confined) dielectric waveguide for millimeter and submillimeter wavelengths was previously reported by the author. The waveguide consists of a thin dielectric tube separating an internal high-dielectric-constant gas from an external low-dielectric-constant gas. The attenuation constant of this form of waveguide usually increases with increasing tube thickness. The thick tube is indispensable for a mechanically stable waveguide. In this paper, anomalous low-loss transmission characteristics in a gas-confined dielectric waveguide with a thick tube are described. Some condtions are theoretically found where the attenuation constant of the waveguide with a thick tube is extremely low, due to tight field confinement within the internal gas. A qualitative explanation of the operation mechanism is also given.     

Propagation in Ferrite-Filled Coaxial Transmission Lines

The dispersion relations (/spl omega/-/spl beta/diagrams) for propagation of the quasi-TEM mode and higher-order symmetric modes in longitudinally magnetized ferrite-filled coaxial waveguide are presented. The dispersion relations for ferrite-filled coaxial cavity resonators are analyzed and presented graphically. The performance and operation of an X-band tunable ferrite filter is evaluated in light of the /spl omega/-/spl beta/diagrams     

低k介质与铜互连集成工艺

阐明了低k介质与铜互连集成工艺取代传统铝工艺在集成电路制造中所发挥的关键作用。依照工艺流程,介绍了如何具体实现IC制造多层互连工艺:嵌入式工艺、低k介质与平坦化、铜电镀工艺与平坦化;阐述了工艺应用现况与存在的难题,给出了国际上较先进的解决方法。     

Complementarity in the Study of Transmission Lines

The principle of complementarity is applied to the slot transmission line. The properties of a dual circuit are investigated. The pairs of several possible duals for a given configuration are correlated and new quantities are defined for use with different types of circuits. A complete parallelism between the two-wire line and the two-slot line is established for the ideal cases and is extended by approximation to include the practical cases. Measurements were made with a two-slot transmission line and its associated probing system. The method of testing the line for balance is discussed. The transverse distribution of the longitudinal current and the attenuation constant were measured. The analogy between the steady-state field in a conducting medium and the electrostatic field in a dielectric is investigated. The expressions for the constants of a two-slot line are given in a form that permits a ready evaluation from experimental data obtained with the electrolytic tank. The measured results are compared with theoretical values.