Towards $5\mu \mathrm{m}$ interconnection pitch with Die-to-Wafer direct hybrid bonding

Die-to-wafer direct hybrid bonding process is foreseen as a key enabler of heterogeneous 3D integration. Hybrid bonding technologies were first developed on W2W assembly reaching 3D interconnection pitch of 1μm. Recently, CEA-Leti demonstrated the feasibility of DTW direct hybrid bonding at 10μm with a specific die bonder (NEO HB) developed by SET Corporation. In this paper, the last improvements of DTW hybrid bonding process flow and die bonder alignment capability are presented. Main results showed an alignment capability improved to <; 1μm which enables bonding of die with <; 5μm interconnection pitch. Finally, multi-interconnection pitch bondings on a wafer were achieved with Cu pitches varying from 5μm to 10μm.