Skybridge: 3-D Integrated Circuit Technology Alternative to CMOS

TL;DR

Skybridge is a novel 3-D integrated circuit technology that overcomes CMOS scaling limitations, offering significant improvements in density, performance, power efficiency, and thermal management for future ICs.

Contribution

The paper introduces Skybridge, a comprehensive 3-D IC fabric technology that integrates device, circuit, and manufacturing innovations for scalable, high-performance, and thermally manageable ICs.

Findings

30-60x higher density than 16-nm CMOS

3.5x better performance per watt

10x reduction in interconnect lengths

Abstract

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. Partial attempts with die-die and layer-layer stacking have their own limitations. We propose a 3-D IC fabric technology, Skybridge[TM], which offers paradigm shift in technology scaling as well as design. We co-architect Skybridge's core aspects, from device to circuit style, connectivity, thermal management, and manufacturing pathway in a 3-D fabric-centric manner, building on a uniform 3-D template. Our extensive bottom-up simulations, accounting for detailed material system structures, manufacturing process, device, and circuit parasitics, carried through for several designs including a designed microprocessor, reveal a 30-60x density, 3.5x performance per watt benefits, and 10X reduction in interconnect lengths vs. scaled 16-nm CMOS. Fabric-level heat extraction features are shown to successfully manage IC thermal profiles in 3-D. Skybridge can provide continuous scaling of integrated circuits beyond CMOS in the 21st century.