Author: Jie Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
Carbon Nanotube Field Effect Transistors (CNFETs) are excellent candidates for building highly energy-efficient future electronic systems. Variations specific to carbon nanotubes (CNTs) pose major obstacles to energy-efficient and robust CNFET digital VLSI. CNFET circuits can suffer from large performance variations, reduced yield, and increased susceptibility to noise. CNT processing techniques alone are inadequate to overcome these challenges. We present an integrated approach, combining CNFET modeling, processing and circuit design, to create VLSI circuits tolerant to CNT variations. Probabilistic models, calibrated using experimental data, are used to analyze the effects of two major sources of CNT variations: metallic CNTs (CNTs with no / very small bandgaps) and grown CNT density variations (due to the non-uniformity in CNT positioning). Using these models, we create a probabilistic framework to derive simple yet useful CNFET processing and circuit design guidelines to overcome CNT variations. The effectiveness of this approach is demonstrated using two examples: 1. CNT variations result in functional failures of CNFET circuits. The failure probability may be reduced through CNFET sizing but at substantial energy costs. A new layout design technique, which engineers correlation among various CNFETs, reduces CNFET circuit failure probability at significantly lower costs. 2. For the first time, the impact of CNT variations on delay variations of CNFET circuits is quantified. We explore the space of CNFET sizing, together with various possibilities to improve CNFET processing, to minimize circuit delay variations at low energy costs.
Author: Albert Lin
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 166
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Book Description
Carbon Nanotube Field Effect Transistor (CNFET) technology has received a lot of attention in the past few years as a promising extension to silicon-CMOS for future digital logic integrated circuits. While recent research has advanced CNFET technology past many important milestones, robust and scalable solutions must be developed to realize the full potential of CNFETs. Thus, this thesis aims to develop a suite of techniques, spanning from material synthesis to circuit solutions, compatible with very-large-scale integration (VLSI). Specifically, to enable the real-world engineering of carbon nanotube integrated circuits, this thesis presents (1) wafer-scale aligned CNT growth, (2) wafer-scale CNT Transfer, (3) wafer-scale device and circuit fabrication techniques, and (4) ACCNT, a VLSI-compatible circuit design solution to surmounting the problem of metallic CNTs. These techniques culminated in the successful demonstration of CNT transistors, inverters, and NAND logic gates on a wafer scale. Furthermore, this thesis sheds light on important design considerations for the demonstration of a simple CNT "computer" and suggests a few critical directions for future work in the field of carbon nanotube technology. In contributing the above, this thesis hopes to propel carbon nanotube technology forward towards the vision of robust, large-scale integrated circuits using high-density carbon nanotubes.
Author: Scott E. Chilstedt
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
The ITRS (International Technology Roadmap for Semiconductors) has recommended that carbon-based transistors be given further study as a potential 0́−Beyond CMOS0́+ technology. Unlike traditional devices with a silicon channel, these transistors have channels made from semiconducting carbon nanomaterials in the form of carbon nanotubes (CNTs) and graphene nanoribbons (GNRs). The research community has given specific attention to these two carbon allotropes because of their outstanding electrical properties, including high mobilities at room temperature, high current densities, and micron-scale mean free paths. Carbon nanomaterial transistors offer many opportunities for circuits and systems, but also present a number of challenges in terms of fabrication, architecture design, and CAD integration. In order to be useful to the semiconductor industry, transistors must be connected together to form higher order circuits. Due to the increased variation and defects in nanometer-scale fabrication, and the regular nature of bottom-up self-assembly, field programmable devices are a promising initial application for such technologies. This thesis details the design and evaluation of a carbon nanomaterial based architecture called FPCNA (field programmable carbon nanotube array). Nanomaterial based devices and circuit building blocks are developed and characterized, including a lookup table created entirely from continuous CNT arrays. To determine the performance of these building blocks, variation-aware physical design tools are used, with statistical timing analysis that can handle both Gaussian and non-Gaussian random variables. When the FPCNA architecture is evaluated using this CAD flow, a 2.75©7 performance improvement is seen over an equivalent CMOS FPGA at a 95% yield. In addition, FPCNA offers a 5.07©7 footprint reduction compared to the baseline FPGA.
Author: Ashok Srivastava
Publisher: CRC Press
ISBN: 9814613118
Category : Science
Languages : en
Pages : 153
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Book Description
Discovery of one-dimensional material carbon nanotubes in 1991 by the Japanese physicist Dr. Sumio Iijima has resulted in voluminous research in the field of carbon nanotubes for numerous applications, including possible replacement of silicon used in the fabrication of CMOS chips. One interesting feature of carbon nanotubes is that these can be me
Author: Aida Todri-Sanial
Publisher: Springer
ISBN: 3319297465
Category : Technology & Engineering
Languages : en
Pages : 340
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Book Description
This book provides a single-source reference on the use of carbon nanotubes (CNTs) as interconnect material for horizontal, on-chip and 3D interconnects. The authors demonstrate the uses of bundles of CNTs, as innovative conducting material to fabricate interconnect through-silicon vias (TSVs), in order to improve the performance, reliability and integration of 3D integrated circuits (ICs). This book will be first to provide a coherent overview of exploiting carbon nanotubes for 3D interconnects covering aspects from processing, modeling, simulation, characterization and applications. Coverage also includes a thorough presentation of the application of CNTs as horizontal on-chip interconnects which can potentially revolutionize the nanoelectronics industry. This book is a must-read for anyone interested in the state-of-the-art on exploiting carbon nanotubes for interconnects for both 2D and 3D integrated circuits.
Author: P. Uma Sathyakam
Publisher: Springer Nature
ISBN: 9811588880
Category : Technology & Engineering
Languages : en
Pages : 134
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Book Description
This book provides a single-source reference on carbon nanotubes for interconnect applications. It presents the recent advances in modelling and challenges of carbon nanotube (CNT)-based VLSI interconnects. Starting with a background of carbon nanotubes and interconnects, this book details various aspects of CNT interconnect models, the design metrics of CNT interconnects, crosstalk analysis of recently proposed CNT interconnect structures, and geometries. Various topics covered include the use of semiconducting CNTs around metallic CNTs, CNT interconnects with air gaps, use of emerging ultra low-k materials and their integration with CNT interconnects, and geometry-based crosstalk reduction techniques. This book will be useful for researchers and design engineers working on carbon nanotubes for interconnects for both 2D and 3D integrated circuits.
Author: Ali Javey
Publisher: Springer Science & Business Media
ISBN: 0387692851
Category : Technology & Engineering
Languages : en
Pages : 275
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Book Description
This book provides a complete overview of the field of carbon nanotube electronics. It covers materials and physical properties, synthesis and fabrication processes, devices and circuits, modeling, and finally novel applications of nanotube-based electronics. The book introduces fundamental device physics and circuit concepts of 1-D electronics. At the same time it provides specific examples of the state-of-the-art nanotube devices.
Author: Saket Gupta
Publisher:
ISBN:
Category :
Languages : en
Pages : 153
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Book Description
Author: Dr. Ashad Ullah Qureshi
Publisher: Concepts Books Publication
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 33
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Book Description
As prevailing copper interconnect technology advances to its fundamental physical limit, interconnect delay due to ever-increasing wire resistivity has greatly limited the circuit miniaturization. Carbon nanotube (CNT) interconnects have emerged as promising replacement materials for copper interconnects due to their superior conductivity. Buffer insertion for CNT interconnects is capable of improving circuit timing of signal nets with limited buffer deployment. However, due to the imperfection of fabricating long straight CNT, there exist significant unidimensional-spatially correlated variations on the critical CNT geometric parameters such as the diameter and density, which will act the circuit performance. This dissertation develops a novel timing driven buffer insertion technique considering unidimensional correlations of variations of CNT. Although the fabrication variations of CNTs are not desired for the circuit designs targeting performance optimization and reliability, these inherent imperfections make them natural candidates for building highly secure physical unclonable function (PUF), which is an advanced hardware security technology. A novel CNT PUF design through leveraging Lorenz chaotic system is developed and we show that it is resistant to many machine learning modeling attacks. In summary, the studies in this dissertation demonstrate that CNT technology is highly promising for performance and security optimizations in advanced VLSI circuit design.
Author: Brajesh Kumar Kaushik
Publisher: Springer
ISBN: 8132220471
Category : Technology & Engineering
Languages : en
Pages : 94
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Book Description
The brief primarily focuses on the performance analysis of CNT based interconnects in current research scenario. Different CNT structures are modeled on the basis of transmission line theory. Performance comparison for different CNT structures illustrates that CNTs are more promising than Cu or other materials used in global VLSI interconnects. The brief is organized into five chapters which mainly discuss: (1) an overview of current research scenario and basics of interconnects; (2) unique crystal structures and the basics of physical properties of CNTs, and the production, purification and applications of CNTs; (3) a brief technical review, the geometry and equivalent RLC parameters for different single and bundled CNT structures; (4) a comparative analysis of crosstalk and delay for different single and bundled CNT structures; and (5) various unique mixed CNT bundle structures and their equivalent electrical models.
