3D integration of 2D electronics

The adoption of three-dimensional (3D) integration has revolutionized NAND flash memory technology, and a similar transformative potential exists for logic circuits, by stacking transistors into the third dimension. This pivotal shift towards 3D integration of logic arrives on the heels of substantial improvements in silicon device structures and their subsequent scaling in size and performance. Yet, advanced scaling requires ultrathin semiconducting channels, which are difficult to achieve using silicon. In this context, field-effect transistors based on two-dimensional (2D) semiconductors have drawn notable attention owing to their atomically thin nature and impressive performance milestones. In addition, 2D materials offer a broader spectrum of functionalities — such as optical, chemical and biological sensing — that extends their utility beyond simple ‘more Moore’ dimensional scaling and enables the development of ‘more than Moore’ technologies. Thus, 3D integration of 2D electronics could bring us unanticipated discoveries, leading to sustainable and energy-efficient computing systems. In this Review, we explore the progress, challenges and future opportunities for 3D integration of 2D electronics.