Pushing the Boundaries of AI Chips: From Monolithic 3D CMOS to Cryogenic Computing

As CMOS scaling approaches its fundamental limits, the explosive rise of AI and LLMs has unveiled profound bottlenecks in computing architectures. This paper presents two groundbreaking paradigms poised to reshape the landscape of high-performance computing and meet the surging demands of AI-driven workloads. The first paradigm is 3D monolithic integration, a revolutionary approach that achieves unprecedented logic density through Complementary FETs (CFETs), where pMOS and nMOS transistors are vertically stacked, and a dramatic expansion of on-chip memory capacity by integrating memory layers atop logic transistors. The second paradigm leverages the transformative potential of operating chips at cryogenic temperatures where transistors exhibit enhanced performance, and parasitic resistances are substantially minimized. These advancements hold the promise of redefining computing efficiency and performance for the AI era.