Thermal stability enhancement of low temperature Cu-Cu bonding using metal passivation technology for advanced electronic packaging.

ABSTRACT: This work investigates the thermal stability of Cu-Cu bonding using a thin Ag passivation layer in applications targeting advanced packaging. Conventional Cu-Cu bonding often requires elevated temperatures (≥250 °C) that can exacerbate thermal stress and limit process flexibility, making multi-chip stacking more challenging. By introducing a 3 nm Ag passivation layer, we demonstrate reliable bonding at lower temperatures with improved durability against high-humidity and high-temperature environments, as confirmed by both Highly Accelerated Stress Tests (HAST) and burn-in measurements. In-situ transmission electron microscopy (TEM) and 4D-STEM strain mapping reveal that Ag diffusion along Cu grain boundaries not only retards abnormal grain growth but also reduces interfacial void formation

SUBMITTER: Hsu MP 

PROVIDER: S-EPMC12728164 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature