Advances and challenges in 2D semiconductor devices for monolithic 3D integration

Abstract 2D semiconductors offer transformative advantages for monolithic 3D (M3D) integration, including atomic-scale thickness, high carrier mobility, and compatibility with low-temperature fabrication processes. These properties minimize interlayer interference and enable efficient heterogeneous integration of diverse functionalities, such as logic, memory, and sensing, on a single chip platform. Their van der Waals (vdW) surfaces with no dangling bond allow for clean interfaces, while high thermal conductivity facilitates efficient heat dissipation in vertically stacked architectures. This perspective article highlights the promise of 2D semiconductors and 2D field effect transistors (FETs) as key enablers for M3D integration, and provides a comprehensive overview of recent advances in 2D channel synthesis, defect and doping control, ohmic contact engineering, and high-k dielectric integration. By addressing these critical challenges 2D-based M3D systems have the potential to unlock next-generation ultra-compact, energy-efficient, and multifunctional electronics through vertically integrated heterogeneous device platforms.