Multi-Functional Self-Assembled Monolayer for Chip-to-Chip and Chip-to-Wafer Hybrid Bonding

Multi-Functional Self-Assembled-Monolayer (MF-SAM) material, SQ-1, with several capabilities such as Cu-oxide removal, Cu-surface protection in both air-ambient as well as under plasma exposure, and desorption/decomposition below the temperature budget of hybrid-bonding (HB) has been developed and demonstrated. This new SQ-1 MF-SAM can preserve the metallic surface of CMP-ed Cu bond pads /electrodes for several days to weeks in air atmosphere prior to HB. We did also observe very good electrical characteristics for tightly pitched 5 μm-size Cu-joints which were formed from the SQ-1 treated Cu electrodes. This demonstrates the high-potentiality of SQ-1 MF-SAM in the chip-to-chip and chip-to-wafer HB.