Contactless Test Access Mechanism for 3D IC

3D IC integration presents many advantages over the current 2D IC integration. It has the potential to reduce the power consumption and the physical size while supporting higher bandwidth and processing speed. Through Silicon Via’s (TSVs) are vertical interconnects between different layers of 3D ICs with a typical 5μm diameter and 50μm length. To test a 3D IC, an access mechanism is needed to apply test vectors to TSVs and observe their responses. However, TSVs are too small for access by current wafer probes and direct TSV probing may affect their physical integrity. In addition, the probe needles for direct TSV probing must be cleaned or replaced frequently. Contactless probing method resolves most of the TSV probing problems and can be employed for small-pitch TSVs. In this dissertation, contactless test access mechanisms for 3D IC have been explored using capacitive and inductive coupling techniques. Circuit models for capacitive and inductive communication links are extracted using 3D full-wave simulations and then circuit level simulations are carried out using Advanced Design System (ADS) design environment to verify the results. The effects of cross-talk and misalignment on the communication link have been investigated. A contactless TSV probing method using capacitive coupling is proposed and simulated. A prototype was fabricated using TSMC 65nm CMOS technology to verify the proposed method. The measurement results on the fabricated prototype show that this TSV probing scheme presents -55dB insertion loss at 1GHz frequency and maintains higher than 35dB signal-to-noise ratio within 5µm distance. A microscale contactless probe based on the principle of resonant inductive coupling has also been designed and simulated. Experimental measurements on a prototype fabricated in TSMC 65nm CMOS technology indicate that the data signal on the TSV can be reconstructed when the distance between the TSV and the probe remains less than 15µm

MIDAS: Automated Approach to Design Microwave Integrated Inductors and Transformers on Silicon

The design of modern radiofrequency integrated circuits on silicon operating at microwave and millimeter-waves requires the integration of several spiral inductors and transformers that are not commonly available in the process design-kits of the technologies. In this work we present an auxiliary CAD tool for Microwave Inductor (and transformer) Design Automation on Silicon (MIDAS) that exploits commercial simulators and allows the implementation of an automatic design flow, including three-dimensional layout editing and electromagnetic simulations. In detail, MIDAS allows the designer to derive a preliminary sizing of the inductor (transformer) on the bases of the design entries (specifications). It draws the inductor (transformer) layers for the specific process design kit, including vias and underpasses, with or without patterned ground shield, and launches the electromagnetic simulations, achieving effective design automation with respect to the traditional design flow for RFICs. With the present software suite the complete design time is reduced significantly (typically 1 hour on a PC based on Intel® Pentium® Dual 1.80GHz CPU with 2-GB RAM). Afterwards both the device equivalent circuit and the layout are ready to be imported in the Cadence environment

The Hidden Costs of Strategic Communications for the International Criminal Court

In little more than a decade, the International Criminal Court (ICC) has received nearly 11,000 requests for its Prosecutor to conduct atrocity investigations around the globe. To date, no such communication has resulted in an official investigation. Nevertheless, the act of publicizing these investigation requests has proven to be an effective, attention-getting tool that can achieve valuable, alternative goals. This fact explains the increasing popularity of “strategic communications” — highly publicized investigation requests aimed not at securing any ICC-related activity, but at obtaining some non-Court related advantage. This Article, which is the first to identify this trend, explains why the international legal community has accepted the instrumental use of the ICC’s communication process with little reflection. It demonstrates why this tolerance is unwise by identifying the potential costs of strategic communications. It then establishes the significance of these concerns by illustrating the specific costs created by the most widely-publicized communication to date: the call for the ICC Prosecutor to investigate Pope Benedict XVI “for rape and other forms of sexual violence as crimes against humanity.

After the Hague Convention on Choice of Court Agreements: China’s role in the future world of international commercial dispute resolution

This dissertation will analyse the framework of international commercial dispute resolution in China after China signing the 2005 Hague Convention. Firstly, it will discuss the Hague Convention from a Chinese perspective and will explore potential conflicts between the Convention and Chinese law. Since China has not yet ratified the Hague Convention, the issues around the ratification of the Convention will also be discussed. Secondly, the dissertation will examine international commercial arbitration, which is an important and popular international commercial dispute resolution method in China. This part will not only discuss arbitration agreements, arbitration procedure and the effects of arbitration awards in China, but will also explore both the “international” and “Chinese” characteristics in arbitration law and practice. It attempts to answer the question of whether or not international commercial arbitration in China is a success. Thirdly, the dissertation will focus on the Chinese International Commercial Court (CICC) and will make a detailed examination of the essential elements of the CICC. It will assess its future role in international commercial dispute resolution. Then the dissertation will provide a number of recommendations based on Chinese legal reality and culture by analysing international commercial courts in other countries. Lastly, the dissertation will look into the future of international commercial dispute resolution in China. It is concluded that after the signature of the Hague Convention, some modification of Chinese legal framework should be made to apply the Convention. Although there has been a creation of numerous international commercial courts, including new China International Commercial Courts (CICC), it is still too early to tell whether CICC will become a genuine competitor of arbitration and a preferred venue of dispute resolution for parities in international commercial business

Temperature-Aware Design and Management for 3D Multi-Core Architectures

Vertically-integrated 3D multiprocessors systems-on-chip (3D MPSoCs) provide the means to continue integrating more functionality within a unit area while enhancing manufacturing yields and runtime performance. However, 3D MPSoCs incur amplified thermal challenges that undermine the corresponding reliability. To address these issues, several advanced cooling technologies, alongside temperature-aware design-time optimizations and run-time management schemes have been proposed. In this monograph, we provide an overall survey on the recent advances in temperature-aware 3D MPSoC considerations. We explore the recent advanced cooling strategies, thermal modeling frameworks, design-time optimizations and run-time thermal management schemes that are primarily targeted for 3D MPSoCs. Our aim of proposing this survey is to provide a global perspective, highlighting the advancements and drawbacks on the recent state-of-the-ar

High-Q 3D Microfabricated Magnetic-core Toroidal Inductors for Power Supplies in Package

Integration of power inductors is a roadblock in realizing highly miniaturized power supply in package (PwrSiP) and power supply on chip (PwrSoC). Inductors in such power system are used for energy storage and filtering, but they dominate in size and loss. This paper presents a novel 3D through-silicon via (TSV) magnetic-core toroidal inductor for PwrSiP. The magnetic-powder-based core is embedded into TSV air-core inductor using a casting method. The unique air-core inductor design with a hollow core and suspended windings enable a complete core filling with microscale magnetic powders. TSV magnetic-core inductors are fabricated in a compact size of 2.4 x 2.4 x 0.28 mm with the core content varying from 63 to 88 weight percent of soft ferrite NiZn powders. Small-signal measurements show a three-fold higher inductance of 112 nH and a 30% higher quality factor of 14.3 at 12.5 MHz for TSV magnetic-core inductors compared to similar TSV air-core inductors. The results are verified by the modelled results. The total core loss is characterized by large-signal measurements. A suitable inductor is implemented in a zero-voltage-switching 12-MHz buck converter. The converter achieves a peak efficiency of 72% and the output power of 2.4 W converting 12 to 5 VDC

Neuromorphic Dynamics at the Nanoscale in Silicon Suboxide RRAM

Resistive random-access memories, also known as memristors, whose resistance can be modulated by the electrically driven formation and disruption of conductive filaments within an insulator, are promising candidates for neuromorphic applications due to their scalability, low-power operation and diverse functional behaviors. However, understanding the dynamics of individual filaments, and the surrounding material, is challenging, owing to the typically very large cross-sectional areas of test devices relative to the nanometer scale of individual filaments. In the present work, conductive atomic force microscopy is used to study the evolution of conductivity at the nanoscale in a fully CMOS-compatible silicon suboxide thin film. Distinct filamentary plasticity and background conductivity enhancement are reported, suggesting that device behavior might be best described by composite core (filament) and shell (background conductivity) dynamics. Furthermore, constant current measurements demonstrate an interplay between filament formation and rupture, resulting in current-controlled voltage spiking in nanoscale regions, with an estimated optimal energy consumption of 25 attojoules per spike. This is very promising for extremely low-power neuromorphic computation and suggests that the dynamic behavior observed in larger devices should persist and improve as dimensions are scaled down

Nanowires for 3d silicon interconnection – low temperature compliant nanowire-polymer film for z-axis interconnect

Semiconductor chip packaging has evolved from single chip packaging to 3D heterogeneous system integration using multichip stacking in a single module. One of the key challenges in 3D integration is the high density interconnects that need to be formed between the chips with through-silicon-vias (TSVs) and inter-chip interconnects. Anisotropic Conductive Film (ACF) technology is one of the low-temperature, fine-pitch interconnect method, which has been considered as a potential replacement for solder interconnects in line with continuous scaling of the interconnects in the IC industry. However, the conventional ACF materials are facing challenges to accommodate the reduced pad and pitch size due to the micro-size particles and the particle agglomeration issue. A new interconnect material - Nanowire Anisotropic Conductive Film (NW-ACF), composed of high density copper nanowires of ~ 200 nm diameter and 10-30 µm length that are vertically distributed in a polymeric template, is developed in this work to tackle the constrains of the conventional ACFs and serves as an inter-chip interconnect solution for potential three-dimensional (3D) applications

Electrical Impedance Tomography for Biomedical Applications: Circuits and Systems Review

There has been considerable interest in electrical impedance tomography (EIT) to provide low-cost, radiation-free, real-time and wearable means for physiological status monitoring. To be competitive with other well-established imaging modalities, it is important to understand the requirements of the specific application and determine a suitable system design. This paper presents an overview of EIT circuits and systems including architectures, current drivers, analog front-end and demodulation circuits, with emphasis on integrated circuit implementations. Commonly used circuit topologies are detailed, and tradeoffs are discussed to aid in choosing an appropriate design based on the application and system priorities. The paper also describes a number of integrated EIT systems for biomedical applications, as well as discussing current challenges and possible future directions

Terahertz Communications and Sensing for 6G and Beyond: A Comprehensive View

The next-generation wireless technologies, commonly referred to as the sixth generation (6G), are envisioned to support extreme communications capacity and in particular disruption in the network sensing capabilities. The terahertz (THz) band is one potential enabler for those due to the enormous unused frequency bands and the high spatial resolution enabled by both short wavelengths and bandwidths. Different from earlier surveys, this paper presents a comprehensive treatment and technology survey on THz communications and sensing in terms of the advantages, applications, propagation characterization, channel modeling, measurement campaigns, antennas, transceiver devices, beamforming, networking, the integration of communications and sensing, and experimental testbeds. Starting from the motivation and use cases, we survey the development and historical perspective of THz communications and sensing with the anticipated 6G requirements. We explore the radio propagation, channel modeling, and measurements for THz band. The transceiver requirements, architectures, technological challenges, and approaches together with means to compensate for the high propagation losses by appropriate antenna and beamforming solutions. We survey also several system technologies required by or beneficial for THz systems. The synergistic design of sensing and communications is explored with depth. Practical trials, demonstrations, and experiments are also summarized. The paper gives a holistic view of the current state of the art and highlights the issues and challenges that are open for further research towards 6G.Comment: 55 pages, 10 figures, 8 tables, submitted to IEEE Communications Surveys & Tutorial