ABSTRACT

Below 10 µm pitch of chip-to-chip interconnection, two complementary 3D solutions are taking over: a back-end-of-line (BEOL)-type technology, based on Cu/SiO2 direct hybrid bonding in the range of a few micrometers of pitch; and da front-end-of-line (FEOL)-type technology, named CoolCube at CEA-Leti, in the range of few tens of nanometers of pitch. The basis of these principles, process integration, challenges, and perspectives are described in this chapter. Besides, whatever the integration, 3D high density is coming with new and common challenges, among which thermal dissipation. Last paragraph of this chapter dedicated to 3D high-density integration will focus on thermal simulation.