3D Integration For HPC & AI, CEA-Leti

2020 Edition. In Device Technology of the Year

The chiplet-on-interposer concept involves integrating a multiplicity of chips on a common Silicon platform unlike the concept of large monolithic systems on chip (SoCs). The active interposer extends this notion by adding smart functions at the interposer level, in particular by integrating CMOS components. The interposer is more than a simple interconnection platform; it becomes the foundation for analog and low power digital and photonic functions and increased 3D communication, especially with network-on-chip architectures. The INTACT proof of concept uses 96-core architecture comprising 6 chiplets (FDSOI 28 nm node) 3D-stacked on an active silicon interposer (CMOS 65 nm node). Advanced 3D Technology: 150,000 chiplet connections using ultra-fine pitch die-to-die interconnect, 14,000 TSVs through interposer. Advanced 3D Architecture: active interposer providing network-on-chip for chiplet-to-chiplet communication in a scalable, configurable, cache coherent system.