Study on the deposition and low-temperature bonding of PVD SiCN thin film

As transistor scaling - the traditional driver of semiconductor performance - approaches fundamental limits, Cu hybrid bonding is becoming a leading strategy for next-generation three-dimensional (3D) integration. This study refines silicon carbon nitride (SiCN) dielectric films deposited by physical vapor deposition and investigates their suitability for Cu/SiCN hybrid bonding. The PVD SiCN layers were synthesized by reactive sputtering while systematically adjusting radio-frequency (RF) power and the Ar / N₂ gas flow ratio. All PVD SiCN films exhibited low-k characteristics, with dielectric constants below 3.3. Increasing either parameter enriched the films in carbon and nitrogen and enhanced film density without appreciably altering surface roughness. Scanning-transmission electron microscopy confirmed void-free, uniform bonding interfaces, and EDS line scans showed a pronounced rise in carbon concentration at the joint, indicating that carbon plays a direct role in SiCN-to-SiCN adhesion. These findings collectively suggest that PVD-SiCN holds great potential as a dielectric material for Cu hybrid bonding applications.