28 research outputs found

    Wireless Testing of Integrated Circuits.

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    Integrated circuits (ICs) are usually tested during manufacture by means of automatic testing equipment (ATE) employing probe cards and needles that make repeated physical contact with the ICs under test. Such direct-contact probing is very costly and imposes limitations on the use of ATE. For example, the probe needles must be frequently cleaned or replaced, and some emerging technologies such as three-dimensional ICs cannot be probed at all. As an alternative to conventional probe-card testing, wireless testing has been proposed. It mitigates many of the foregoing problems by replacing probe needles and contact points with wireless communication circuits. However, wireless testing also raises new problems which are poorly understood such as: What is the most suitable wireless communication technique to employ, and how well does it work in practice? This dissertation addresses the design and implementation of circuits to support wireless testing of ICs. Various wireless testing methods are investigated and evaluated with respect to their practicality. The research focuses on near-field capacitive communication because of its efficiency over the very short ranges needed during IC manufacture. A new capacitive channel model including chip separation, cross-talk, and misalignment effects is proposed and validated using electro-magnetic simulation studies to provide the intuitions for efficient antenna and circuit design. We propose a compact clock and data recovery architecture to avoid a dedicated clock channel. An analytical model which predicts the DC-level fluctuation due to the capacitive channel is presented. Based on this model, feed-forward clock selection is designed to enhance performance. A method to select proper channel termination is discussed to maximize the channel efficiency for return-to-zero signaling. Two prototype ICs incorporating wireless testing systems were fabricated and tested with the proposed methods of testing digital circuits. Both successfully demonstrated gigahertz communication speeds with a bit-error rate less than 10^−11. A third prototype IC containing analog voltage measurement circuits was implemented to determine the feasibility of wirelessly testing analog circuits. The fabricated prototype achieved satisfactory voltage measurement with 1 mV resolution. Our work demonstrates the validity of the proposed models and the feasibility of near-field capacitive communication for wireless testing of ICs.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/93993/1/duelee_1.pd

    Optical interconnect for integrated circuits

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    This thesis presents the research pertaining to the development of essential components of optical interconnect between dies in a package, involving both guided and free-space propagation of light. In order to pursue such an objective, it required the development of a simpler approach to the design of planar silica lens pairs; develop the technology for fabricating such lens pairs, and modeling the critical factors, like alignment non-idealities, that affect the optical loss of such a scheme involving both guided and free-space propagation. A methodology based on the ABCD matrix method has been developed to design and evaluates the performance of a planar silica lens pair system for a prescribed (‘ideal’) free-space propagation distance. The optical loss of a designed system under various fabrication and experimental imperfections has been calculated and verified against the simulation results obtained from the commercial beam propagation method (BPM) software, BPM_CAD by Optiwave. A two-level optical system comprising of a planar silica lens pair and a pair of 45° micromirror, which is equivalent to a chip to chip optical interconnects in a 3D integrated system, has been theoretically analysed for optical loss due to micromirrors deviation from the ideal 45° and an angular tilt between the two levels. For the implementation of the planar silica lens pair, a hollow cathode PECVD system was used to deposit low stress thick graded index silica film on silicon wafer from a mixture of O2/SiH4/CF4 gases. Technique of depositing low stress thick fluorine doped silica film was developed and films up to 38 ”m thickness with very low compressive stress (16 Mpa) were deposited on silicon substrate. Lens front-face curvature was defined by vertical deep oxide etch using a state of art STS–ICP Advanced Oxide Etch (AOE) system. The planar silica lens pair designed for 200 and 500 ”m of ‘ideal’ free-space propagation distance were fabricated and optically tested. A successful implementation of such a scheme, involving guided and free-space optical propagation has been demonstrated for the first time. Practical demonstration and optical characterization of in-plane chip to chip optical interconnects has been performed, however, integration of 45° micromirror and practical demonstration of stacked-die optical interconnect based on planar silica lens pair has been left for future work

    Topical Workshop on Electronics for Particle Physics

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    The purpose of the workshop was to present results and original concepts for electronics research and development relevant to particle physics experiments as well as accelerator and beam instrumentation at future facilities; to review the status of electronics for the LHC experiments; to identify and encourage common efforts for the development of electronics; and to promote information exchange and collaboration in the relevant engineering and physics communities

    Wireless Terahertz Communications: Optoelectronic Devices and Signal Processing

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    Novel THz device concepts and signal processing schemes are introduced and experimentally confirmed. Record-high data rates are achieved with a simple envelope detector at the receiver. Moreover, a THz communication system using an optoelectronic receiver and a photonic local oscillator is shown for the first time, and a new class of devices for THz transmitters and receivers is investigated which enables a monolithic co-integration of THz components with advanced silicon photonic circuits

    Advanced Trends in Wireless Communications

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    Physical limitations on wireless communication channels impose huge challenges to reliable communication. Bandwidth limitations, propagation loss, noise and interference make the wireless channel a narrow pipe that does not readily accommodate rapid flow of data. Thus, researches aim to design systems that are suitable to operate in such channels, in order to have high performance quality of service. Also, the mobility of the communication systems requires further investigations to reduce the complexity and the power consumption of the receiver. This book aims to provide highlights of the current research in the field of wireless communications. The subjects discussed are very valuable to communication researchers rather than researchers in the wireless related areas. The book chapters cover a wide range of wireless communication topics

    Wide Bandgap Based Devices

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    Emerging wide bandgap (WBG) semiconductors hold the potential to advance the global industry in the same way that, more than 50 years ago, the invention of the silicon (Si) chip enabled the modern computer era. SiC- and GaN-based devices are starting to become more commercially available. Smaller, faster, and more efficient than their counterpart Si-based components, these WBG devices also offer greater expected reliability in tougher operating conditions. Furthermore, in this frame, a new class of microelectronic-grade semiconducting materials that have an even larger bandgap than the previously established wide bandgap semiconductors, such as GaN and SiC, have been created, and are thus referred to as “ultra-wide bandgap” materials. These materials, which include AlGaN, AlN, diamond, Ga2O3, and BN, offer theoretically superior properties, including a higher critical breakdown field, higher temperature operation, and potentially higher radiation tolerance. These attributes, in turn, make it possible to use revolutionary new devices for extreme environments, such as high-efficiency power transistors, because of the improved Baliga figure of merit, ultra-high voltage pulsed power switches, high-efficiency UV-LEDs, and electronics. This Special Issue aims to collect high quality research papers, short communications, and review articles that focus on wide bandgap device design, fabrication, and advanced characterization. The Special Issue will also publish selected papers from the 43rd Workshop on Compound Semiconductor Devices and Integrated Circuits, held in France (WOCSDICE 2019), which brings together scientists and engineers working in the area of III–V, and other compound semiconductor devices and integrated circuits

    Topical Workshop on Electronics for Particle Physics

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