Plasma-Induced Degradation of a UV Tape in D2W Hybrid Bonding: Particle Generation Mechanisms and Pre-UV Suppression Strategy

Die-to-wafer (D2W) hybrid bonding has garnered great attention due to high flexibility, ultrafine pitch, and high density. However, the limited bonding area is very sensitive to the small defect density at the bonding interface, leading to poor yields. Therefore, maintaining cleanliness is a crucial and inevitable challenge. This research first discovers that a large number of particles are produced from the ultraviolet (UV) tape during plasma activation and proposes an innovative and effective solution to inhibit the particles by UV exposure from the topside. After the UV treatment, the number of particles decreases by approximately 139 times, which is because of the increased polymerization degree of the UV tape. The significant increase of the C–O/C–N single-bond peaks in the FTIR and XPS spectra validates the high polymerization degree and improved stability of the tape after UV treatment, and the proportion of long-chain structure contributes to superior particle suppression capabilities. This research provides an idea to restrain the defects in the plasma activation process and improve the interface quality of D2W hybrid bonding.