VLSI Design

This book provides some recent advances in design nanometer VLSI chips. The selected topics try to present some open problems and challenges with important topics ranging from design tools, new post-silicon devices, GPU-based parallel computing, emerging 3D integration, and antenna design. The book consists of two parts, with chapters such as: VLSI design for multi-sensor smart systems on a chip, Three-dimensional integrated circuits design for thousand-core processors, Parallel symbolic analysis of large analog circuits on GPU platforms, Algorithms for CAD tools VLSI design, A multilevel memetic algorithm for large SAT-encoded problems, etc

Cutting Edge Nanotechnology

The main purpose of this book is to describe important issues in various types of devices ranging from conventional transistors (opening chapters of the book) to molecular electronic devices whose fabrication and operation is discussed in the last few chapters of the book. As such, this book can serve as a guide for identifications of important areas of research in micro, nano and molecular electronics. We deeply acknowledge valuable contributions that each of the authors made in writing these excellent chapters

Performance analysis of fault-tolerant nanoelectronic memories

Performance growth in microelectronics, as described by Moore’s law, is steadily approaching its limits. Nanoscale technologies are increasingly being explored as a practical solution to sustaining and possibly surpassing current performance trends of microelectronics. This work presents an in-depth analysis of the impact on performance, of incorporating reliability schemes into the architecture of a crossbar molecular switch nanomemory and demultiplexer. Nanoelectronics are currently in their early stages, and so fabrication and design methodologies are still in the process of being studied and developed. The building blocks of nanotechnology are fabricated using bottom-up processes, which leave them highly susceptible to defects. Hence, it is very important that defect and fault-tolerant schemes be incorporated into the design of nanotechnology related devices. In this dissertation, we focus on the study of a novel and promising class of computer chip memories called crossbar molecular switch memories and their demultiplexer addressing units. A major part of this work was the design of a defect and fault tolerance scheme we called the Multi-Switch Junction (MSJ) scheme. The MSJ scheme takes advantage of the regular array geometry of the crossbar nanomemory to create multiple switches in the fabric of the crossbar nanomemory for the storage of a single bit. Implementing defect and fault tolerant schemes come at a performance cost to the crossbar nanomemory; the challenge becomes achieving a balance between device reliability and performance. We have studied the reliability induced performance penalties as they relate to the time (delay) it takes to access a bit, and the amount of power dissipated by the process. Also, MSJ was compared to the banking and error correction coding fault tolerant schemes. Studies were also conducted to ascertain the potential benefits of integrating our MSJ scheme with the banking scheme. Trade-off analysis between access time delay, power dissipation and reliability is outlined and presented in this work. Results show the MSJ scheme increases the reliability of the crossbar nanomemory and demultiplexer. Simulation results also indicated that MSJ works very well for smaller nanomemory array sizes, with reliabilities of 100% for molecular switch failure rates in the 10% or less range

EFFECTS OF DIVERSE VARIABLES ON RESISTIVITY, RHEOLOGY, AND NETWORK VISUALIZATION OF ELECTRICALLY CONDUCTIVE EPOXY-CNT COMPOSITES

The addition of high-aspect ratio nanometric conductive fillers (i.e., carbon nanotubes [CNTs]) to an epoxy matrix has been shown to improve electrical conductivity by many orders of magnitude. These nanocomposites, well-suited for electrostatic dissipation and electromagnetic interference applications, are of intense interest to the aerospace industry where epoxy resins are already widely employed. Future adoption and commercial production efforts are limited by a lack of understanding of how electrical and rheological properties of uncured mixtures relate to the finished composite, how they change throughout the epoxy curing process, or how these materials are affected by extreme operating environments. To bridge these gaps, the viscosity and electrical properties of uncured mixtures were characterized and correlated to cured values, potentially allowing for quality control at a point in the production process where remediation is possible. Rare-earth oxide nanoparticles, europium-doped yttria, were synthesized into CNT walls, enhancing the contrast of the conductive network in scanning electron microscopy and micro-computed tomography while also granting deep-UV fluorescence. Lastly, in-situ electrical measurements of an epoxy-CNT composite were conducted under simulated low-earth orbit conditions with instantaneous decreases in resistivity as large as 60% being documented.DOD SpaceLieutenant Commander, United States NavyApproved for public release. Distribution is unlimited

Understanding Controlled Evaporation Of Microdroplets Towards Scalable Micro/Nano Manufacturing

This research investigates the controlled evaporation of microdroplets to the nano scale regime for scalable micro/nano manufacturing. A customized direct write inkjet printing system was utilized to generate monodisperse microdroplets of different fluid types. Two novel approaches were employed to achieve the research objective. The first approach incorporated a convective heat source (i.e. resistive heated ring) to induce controlled heat flux for microdroplet evaporation after ejection from the inkjet system

Nano and Micro Morphology of Type I Collagen as a Function of Disease and Drug Treatment.

Type I collagen, the most abundant protein in the human body, is the primary organic component of bone and forms fibrils with a periodic spacing (D-spacing) along the fibril axis. These collagen fibrils are organized into larger hierarchical structures. Using atomic force microscopy (AFM), individual microfibrils were quantitatively characterized and a minimum of 90 collagen molecules were required before D-spacing was observed. The arrangement of type I collagen fibrils into microstructures in bone tissue altered upon estrogen depletion, a model for postmenopausal osteoporosis, as well as drug treatments for osteoporosis. Micro-scale structural changes were measured in a rabbit animal model from the following treatment groups: Sham, ovariectomized (OVX), OVX + alendronate (ALN), OVX + cathepsin K inhibitor (CatKI), and OVX + estrogen replacement therapy (ERT). AFM images were collected for 84 animals across all five treatment groups. A fibril-by-fibril analysis was conducted by hand-coding fibrils into Parallel (collagen bundles or collagen sheets) or Oblique microstructures. In cortical bone, OVX increased the proportion of fibrils coded as Oblique and decreased the proportion of fibrils coded as Parallel with statistical significance (p < 0.05). Treatment with ALN or ERT partially prevented this change from occurring and treatment with CatKI completely prevented this change from occurring within error. An automated imaged level analysis was conducted using an autocorrelation technique and calculating a fibril alignment parameter (FAP) to describe the degree of local collagen fibril alignment in an image. At this level of hierarchical structure, OVX altered trabecular bone and showed no changes to cortical bone. Treatment with CatKI prevented the trabecular microstructural change from occurring but also introduced a change to the cortical bone. Treatment with ALN altered both the cortical and trabecular microstructure. Sites of collagen interactions with the collagen chaperone PEDF, pigment epithelium derived factor, were imaged in bone tissue by phase imaging during tapping mode AFM. Gold nanoparticles were used as a secondary tag on PEDF to allow detection of PEDF binding in tissue. PEDF bound heterogeneously and was detected between collagen fibrils with a low amount of alignment.PhDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133366/1/mcauble_1.pd

HIGH PERFORMANCE CLOCK DISTRIBUTION FOR HIGH-SPEED VLSI SYSTEMS

Tohoku University堀口 進課

Characterising, understanding and predicting the performance of structural power composites

Dramatic improvements in power generation, energy storage, system integration and light-weighting are needed to meet increasingly stringent carbon emissions targets for future aircraft and road vehicles. The electrification of transport could significantly reduce direct CO2 emissions; however, battery energy and power density limitations pose a major technological barrier. The introduction of multifunctional structural power composites (SPCs), which simultaneously provide mechanical load-bearing and electrochemical energy storage, offers new possibilities. By replacing conventional materials with SPCs, electrical performance requirements could be relaxed, and vehicle mass could be reduced; however, for SPCs to outperform monofunctional systems, significant performance and reliability improvements are still required. The use of computational models to support experimental efforts has so far been overlooked, despite wide recognition of the benefits of such a combined approach. The aim of this work was to develop predictive finite element models for structural supercapacitor composites (SSCs), and use them to investigate their mechanical, electrical, and electrochemical behaviour. A unit cell modelling technique was used to generate realistic mesoscale models of the complex microstructure of SSCs. The effects of composite manufacturing processes on the final performance of SSCs were investigated through characterisation and modelling of compaction and manufacturing defects. Numerical predictions of the elastic properties of SSCs were evaluated against data from the literature; and the presence of defects was shown to significantly degrade performance. Motivated by the large series resistance of SSCs, direct conduction models were developed to better understand electrical charge transport. Based on investigations of various current collector geometries, design strategies for the mitigation of resistive losses were proposed. To enable analysis of the combined mechanical-electrochemical behaviour of SSCs, an ion transport user element subroutine was developed but could not be validated. Overall, this work demonstrates that substantial improvements in the mechanical and electrical properties of SSCs are possible through control of the composite microstructure. The models developed in this work provide guidance for the optimisation of manufacturing processes and the design of new SSC architectures, and underpin the future certification and deployment of these emerging materials.Open Acces