Passivating Interfacial Pore Defects with Light Atoms To Enhance Heat Transport Across Cu/a-SiO₂ Interfaces

As interconnect pitches in three-dimensional integrated circuits approach submicrometer scale, interfacial thermal conductance (ITC) across Cu/a-SiO₂ hybrid-bonded interfaces becomes a major heat-dissipation bottleneck. In practice, nanoscale pores and process-induced light-atom incorporation further complicate interfacial heat transport, yet their combined influence remains unclear. Here, using two-temperature-model molecular dynamics with realistic interatomic potentials, we elucidate how pores and light atoms jointly regulate ITC. Pores on the Cu side strongly suppress mid-frequency phonons and significantly reduce ITC, whereas pores on the a-SiO₂ side exert a much weaker effect. Light-atom incorporation induces a nonmonotonic ITC dependence on treatment length and concentration, governed by the competition between pore-induced surface states, which disrupt the low-mid-high phonon redistribution pathway, and light-atom-enabled spectral reshaping that channels energy into high-frequency modes resilient to pore suppression. These findings establish a unified vibrational framework for pore-light-atom interactions and provide process-compatible guidance for thermal management in ultrafine-pitch hybrid bonding.