Die to wafer 3D stacking for below 10um pitch microbumps

Processing of bump-less or embedded microbumps is introduced in this paper as an approach which enables scaling microbumps for below 10um pitches. Landing wafer is standard damascene process and in top wafer bumps are embedded in a soft backed polymer. Later during thermo-compression bonding this polymer is cured to bond two chips together. Process flow and results of TC bonding is discussed in this paper.