摘要
While SiO2/Cu hybrid bonding is widely adopted in mature applications, scaling to ultrafine pitches introduces misalignment-induced leakage, motivating silicon carbon nitride (SiCN)/nanocrystalline-nanotwinned Cu (NNT-Cu) hybrid bonding as a next-generation solution. Here, the SiCN bonding mechanism is clarified, achieving a high room-temperature (RT) bonding energy of 0.67 J/m2. A two-step plasma activation with water wetting, without external pressure, is critical for RT bonding. Electron paramagnetic resonance (EPR) analysis demonstrates that, despite similar surface dangling bond densities in SiCN and SiO2, differences in dangling bond types—associated with reactive Si, C, and N sites—enable multiple condensation polymerization reactions that enhance bonding. After chemical-mechanical planarization (CMP) optimization, a 13.1 nm dished NNT-Cu pad is achieved, with Rq values of 4.53 nm (NNT-Cu) and 0.34 nm (SiCN). Pre-bonding at 45 ℃ and 1 MPa with water wetting, followed by post-annealing at 150 ℃ without external pressure, yields a low contact resistance of 9.2 × 10-9 Ω·cm2, demonstrating its potential for ultrafine-pitch applications. © 2026 Elsevier B.V.