Three-dimensional integrated circuits (3D ICs) stack multiple die or wafers vertically, connected by through-silicon vias (TSVs) or hybrid bonding. The approach increases functional density, reduces interconnect length—improving latency and power—and enables heterogeneous integration of logic, memory, and sensors. Commercial deployment includes high-bandwidth memory (HBM) for AI accelerators, stacked image sensors, and 3D NAND flash. Development and commercialization are advancing; the technology is critical for next-generation processors and memory systems.
Conventional 2D scaling faces interconnect and power limits. 3D integration offers a path: vertical stacking reduces wire length and enables new architectures. Challenges include thermal management—heat must escape stacked layers—testability, cost, and yield. Research continues into hybrid bonding for finer pitch, thermal solutions, and design tools. 3D ICs are increasingly central to high-performance computing and memory.