Van der Waals epitaxy and beyond for monolithic 3D integration

Abstract As the limitations of silicon-based technologies approach their physical boundaries, monolithic three-dimensional integration (M3D) and two-dimensional (2D) materials, such as transition metal dichalcogenides (TMDs), have emerged as promising solutions for continuous scaling in semiconductor devices. This perspective explores the evolution of van der Waals (vdW) epitaxy and its potential to integrate TMDs into M3D structures. By circumventing lattice mismatch issues, vdW epitaxy allows the formation of high-quality single-crystal heterostructures across diverse material systems. However, the challenge of achieving films with uniform thickness control remains unresolved. Herein, advanced epitaxial growth techniques for TMDs are reviewed, including quasi-vdW epitaxy, vdW recrystallization, and remote epitaxy, whilst also introducing emerging approaches, such as hypotaxy and interfacial epitaxy. These emerging techniques have the potential to produce large-area defect-free films with controllable thicknesses. Ultimately, the development of new epitaxial methods specifically designed for TMDs is essential for the future integration of 2D materials into industrial applications.