System-on-Wafer: 2D and 3D Technologies for Heterogeneous Systems

Heterogeneous integration is a must for future mm-wave, sub-THz communication systems: there is fierce competition to develop components and systems with high data communication bandwidth. Many technical challenges need to be addressed in different areas of physics: mechanical, electromagnetic, thermal. The solutions to these multi-physics problems must be cost-effective with a reasonable environmental impact in order to have a chance to be in pockets, cars, communication infrastructures and others in a few years. CEA-Leti is investigating different 3D integration solutions, mastered internally for tens of years, from the simplest to the most advanced: chiplet copper pillar assembly and die to wafer direct hybrid bonding. This presentation will focus on the issues raised by mm-wave/sub-THz heterogeneous integrated systems and the recent research and solutions developed, bearing in mind that their financial but also environmental costs are parameters that are as important to manage as the physical/technical parameters.