This paper analyzes the limitations of the existing interconnect technologies and design methodologies and presents a novel three-dimensional (3-D) chip design strategy that exploits the vertical dimension to alleviate the interconnect related problems and to facilitate heterogeneous integration of technologies to realize a system-on-a-chip (SoC) design. A comprehensive analytical treatment of these 3-D ICs has been presented and it has been shown that by simply dividing a planar chip into separate blocks, each occupying a separate physical level interconnected by short and vertical interlayer interconnects (VILICs), significant improvement in performance and reduction in wire-limited chip area can be achieved, without the aid of any other circuit or design innovations. A scheme to optimize the interconnect distribution among different interconnect tiers is presented and the effect of transferring the repeaters to upper Si layers has been quantified in this analysis for a two-layer 3-D

Abstract- Although the emerging three-dimensional integration technology can significantly reduce interconnect delay, chip area, and power dissipation in nanometer technologies, its impact on overall system performance is still poorly understood due to the lack of tools and systematic flows to evaluate 3D microarchitectural designs. The contribution of this paper is the development of MEVA-3D, an automated physical design and architecture performance estimation flow for 3D architectural evaluation which includes 3D floorplanning, routing, interconnect pipelining and automated thermal via insertion, and associated die size, performance, and thermal modeling capabilities. We apply this flow to a simple, out-of-order superscalar microprocessor to evaluate the performance and thermal behavior in 2D and 3D designs, and demonstrate the value of MEVA-3D in providing quantitative evaluation results to guide 3D architecture designs. In particular, we show that it is feasible to manage thermal challenges with a combination of thermal vias and double-sided heat sinks, and report modest system performance gains in 3D designs for these simple test examples. 1.

Introduction Chip industry obeys a number of laws, various kinds of laws. Mathematical laws if accurate models can be formulated, physical laws, especially solid state physics, obtained by observation and induction, chemical laws pertinent for the manufacturing processes, economical and judicial laws that concern such industries. The most famous and most cited law of chip industry is the one that Gordon Moore formulated in 1964 after observing trends in the then very young field of integration of electronic circuits. Mathematically formulated, Moore's law reads as follows: ## ## # ## (1) where # is the maximum number of devices on a single chip. The proportionality constant is called the moore exponent which according to Moore, with years as the unit of time, equaled ###. An even older law, also formulated after observing properties of early logic circuitry in computers, is known as Re

Most previous 3D IC research focused on “stacking ” traditional 2D silicon layers, so the interconnect reduction is limited to interblock delays. In this paper, we propose techniques that enable efficient exploration of the 3D design space where each logical block can span more than one silicon layers. Although further power and performance improvement is achievable through fine grain 3D integration, the necessary modeling and tool infrastructure has been mostly missing. We develop a cube packing engine which can simultaneously optimize physical and architectural design for effective utilization of 3D in terms of performance, area and temperature. Our experimental results using a design driver show 36 % performance improvement (in BIPS) over 2D and 14 % over 3D with single layer blocks. Additionally multi-layer blocks can provide up to 30 % reduction in power dissipation compared to the single-layer alternatives. Peak temperature of the design is kept within limits as a result of thermal-aware floorplanning and thermal via insertion techniques. 1.

3-D integration presents many new opportunities for architects and embedded systems designers. However, 3-D integration has not yet been explored by the cryptographic hardware community. Traditionally, crypto coprocessors have been implemented as a separate die or by utilizing one or more cores in a chip multiprocessor. These methods have their drawbacks and limitations in terms of tamper-resistance, side-channel immunity and performance. In this work we propose a new class of co-processors that are “snapped-on ” to the main processor using 3-D integration, and we investigate their security ramifications. These 3-D co-processors hold many advantages over previous implementations. This paper begins with an overview of 3-D integration and its prior applications. We then outline security threat models relevant to crypto co-processors and discuss the advantages and disadvantages of using a dedicated 3-D crypto co-processor compared to traditional, commodity, off-chip crypto co-processors. We also discuss the performance improvements that can be gained from using a 3-D approach. 1

Continuous scaling of VLSI circuits is reducing gate delays but rapidly increasing interconnect delays. Semiconductor Industry Association (SIA) roadmap predicts that, beyond the 130 nm technology node, performance improvement of advanced VLSI is likely to begin to saturate unless a paradigm shift from present IC architecture is introduced. This paper presents a comprehensive analytical treatment of ICs with multiple Si layers (3-D ICs). It is shown that significant improvement in performance (more than 145%) and reduction in wire-limited chip area can be achieved with 3-D ICs with vertical inter-layer interconnects (VILICs). This analysis is based on dividing a chip into separate blocks, each occupying a separate physical level. A scheme to optimize interconnect distribution among different interconnect tiers is presented and the effect of transferring the repeaters to upper Si layers has been quantified in this analysis. Furthermore, thermal analysis of ICs with two Si layers is pres...

In this article we propose techniques that enable efficient exploration of the 3D design space, where each logical block can span more than one silicon layer. Fine-grain 3D integration provides reduced intrablock wire delay as well as improved power consumption. However, the corresponding power and performance advantage is usually underutilized, since various implementations of multilayer blocks require novel physical design and microarchitecture infrastructure to explore 3D microarchitecture design space. We develop a cubic packing engine which can simultaneously optimize physical and architectural design for efficient vertical integration. This technique selects the individual unit designs from a set of single-layer or multilayer implementations to get the best microarchitectural design in terms of performance, temperature, or both. Our experimental results using a design driver of a high-performance superscalar processor show a 36 % performance improvement over traditional 2D for 2–4 layers and 14 % over 3D with single-layer unit implementations. Since thermal characteristics of 3D integrated circuits are among the main challenges, thermal-aware floorplanning and thermal via insertion techniques are employed to keep the peak temperatures below threshold.