Abstract: In this talk, I will discuss the potential for two-dimensional (2D) materials to enable both ​“More Moore”as well as ​“More than Moore” technologies. ​“More Moore” refers to an increasing number of transistor-count per chip, whereas ​“More Than Moore” refers to the increasing number of functionalities per chip.

The aggressive scaling of transistors has led to faster and smaller electronic devices, with future technology roadmaps indicating gate lengths as small as 6 nm using vertically stacked gate-all-around (GAA) architecture. To further enhance device integration and computational capabilities, 3D integration has become crucial. Industry advancements in 3D integration have reduced interconnect density and improved performance in electronic devices. However, silicon-based logic technologies face challenges with monolithic inter-layer vias (MIVs) and scaling below a gate length of 10 nm. Ultra-thin-body (UTB) channel materials such as 2D semiconductors offer solutions, with significant advancements in their synthesis and performance. While progress has been made in 2D/silicon hybrid 3D integration, achieving fully 2D monolithic 3D integration remains a challenge. I will discuss some of our recent demonstrations on monolithic 3D integration of large-area-grown MoS2 and WSe2 2D FETs, showcasing wafer-scale and multi-tier 3D integration with low thermal requirements. The findings open possibilities for sophisticated and functionally diverse 2D material-based chips with increased tiers in the third dimension.

While 3D integration has a huge potential for ​“More Moore”, it can be equally effective towards the integration of non-computational systems such as optical/gas/chemical sensors, memory devices, radio-frequency devices, etc., in different tiers of a 3D IC leading to better energy efficiency, lower latency, lower cost, increased yield and reliability, and multifunctionality within a smaller volume. This approach is referred to as ​“More than Moore”. In this context, 2D materials offer tremendous potential. For example, various types of sensors such as photodetectors, chemical sensors, biological sensors, touch sensors, and radiation sensors have been demonstrated using 2D devices. Emerging neuromorphic, stochastic, straintronic, and biomimetic edge devices that require integration of sensing, computing, and storage capabilities have also been realized using 2D material including several reports from our group, which I will also discuss in my talk.