Power -Delivery Network in 3D ICs: Monolithic 3D vs. Skybridge 3D CMOS

Design for power-delivery network (PDN) is one of the major challenges in 3D IC technology. In the typical layer-by-layer stacked monolithic 3D (M3D) approaches, PDN has limited accessibility to the device layer away from power/ground source due to limited routability and routing resources in the vertical direction. This results in an incomplete and low-density PDN design and also severe IR-drop issue. Some improved M3D approaches try to enlarge design area to create additional vertical routing resources for robust and high-density PDN design.

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Structure Discovery for Gene Expression Networks with Emerging Stochastic Hardware

Gene Expression Networks (GENs) attempt to model how genetic information stored in the DNA (Genotype) results in the synthesis of proteins, and consequently, the physical traits of an organism (Phenotype). Deciphering GENs plays an important role in a wide range of applications from genetic studies of the origins of life to personalized healthcare. Probabilistic graphical models such as Bayesian Networks (BNs) are used to perform learning and inference of GENs from genetic data.

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Skybridge-3D-CMOS: A Fine-Grained 3D CMOS Integrated Circuit Technology

Parallel and monolithic 3D integration directions realize 3D integrated circuits (ICs) by utilizing layer-by-layer implementations, with each functional layer being composed in 2D. In contrast, vertically-composed 3D CMOS has eluded us likely due to the seemingly insurmountable requirement of highly customized complex routing and regional 3D doping to form and connect CMOS pull-up and pull-down networks in 3D. In the current layer-by-layer directions, routing can be worse than 2D CMOS because of the limited pin access.

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Towards Automatic Thermal Network Extraction in 3D ICs

Thermal management is one of the critical challenges in 3D integrated circuits. Incorporating thermal optimizations during the circuit design stages requires a convenient automatic method of doing thermal characterization for feedback purposes. In this paper, we present a methodology, which supports thermal characterization by automatically extracting the steady-state thermal modeling resistance network from a post-placement physical design. The method follows a two-level hierarchical approach.

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Routability in 3D IC Design: Monolithic 3D vs. Skybridge 3D CMOS

Conventional 2D CMOS technology is reaching fundamental scaling limits, and interconnect bottleneck is dominating integrated circuit (IC) power and performance. While 3D IC technologies using Through Silicon Via or Monolithic Inter-layer Via alleviate some of these challenges, they follow a similar layout and routing mindset as 2D CMOS. This is insufficient to address routing requirements in high-density 3D ICs and even causes severe routing congestion at large-scale designs, limiting their benefits and scalability.

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Skybridge-3D-CMOS: A Vertically-Composed Fine-Grained 3D CMOS Integrated Circuit Technology

Parallel and monolithic 3D integration directions offer pathways to realize 3D integrated circuits (ICs) but still lead to layer-by-layer implementations, each functional layer being composed in 2D first. This mindset causes challenging connectivity, routing and layer alignment between layers when connected in 3D, with a routing access that can be even worse than 2D CMOS, which fundamentally limits their potential.

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Skybridge: 3-D Integrated Circuit Technology Alternative to CMOS

Continuous scaling of CMOS has been the major catalyst in miniaturization of integrated circuits (ICs) and crucial for global socio-economic progress. However, scaling to sub-20nm technologies is proving to be challenging as MOSFETs are reaching their fundamental limits and interconnection bottleneck is dominating IC operational power and performance. Migrating to 3-D, as a way to advance scaling, has eluded us due to inherent customization and manufacturing requirements in CMOS that are incompatible with 3-D organization.

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Architecting NP-Dynamic Skybridge

This paper introduces a new fine-grained 3D IC fabric technology called NP-Dynamic Skybridge. Skybridge is a family of 3D IC technologies that provides fine-grained vertical integration. In comparison to the original 3D Skybridge, the NP-Dynamic approach enables a more comprehensive logic style for improved efficiency. It addresses device, circuit, connectivity and manufacturability requirements with an integrated 3D mindset. The NP-Dynamic 3D circuit style enables wide range of logic expressions, simple clocking scheme, and reduces buffer requirements.

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Manufacturing Pathway and Experimental Demonstration for Nanoscale Fine-Grained 3-D Integrated Circuit Fabric

At Sub-20nm technologies CMOS scaling faces severe challenges primarily due to fundamental device scaling limitations, interconnection overhead and complex manufacturing. Migration to 3-D has been long sought as a possible pathway to continue scaling; however, CMOS’s intrinsic requirements are not compatible for fine-grained 3-D integration. In [1], we proposed a truly fine-grained 3-D integrated circuit fabric called Skybridge that solves nanoscale challenges and achieves orders of magnitude benefits over CMOS.

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Unconventional Nanocomputing with Physical Wave Interference Functions

In this chapter, we introduce a new fully generic computational paradigm for post-CMOS integrated circuits based on emerging wave-like physical phenomenon (e.g. spin waves), called Wave Interference Functions (WIF). Waves offer new features and opportunities for logic circuits with inherent support for multi-valued data representation, communication and computation. Multi-valued information processing occurs through wave interference, and multi-valued communication between processing elements is through wave propagation.

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Nanocircuits