通过混合键合加速了3D异构集成的商业化,因此,Cu-聚合物键合作为克服常规Cu-SiO2混合键合的局限性的一种手段已经获得了极大的关注,提供与其他制造工艺的高兼容性。聚合物提供强大的粘合强度和低介电常数,实现高可靠性的高速信号传输,但具有低的热机械稳定性。由于热降解和不稳定的锚定,以前没有实现聚合物的热机械稳定性。为了克服这些限制,提出了通过N-杂环卡宾(NHC)纳米层进行晶片级Cu-聚合物键合的3D异质集成,提供超稳定的包装密度,结晶度和热性能。NHC纳米层通过电化学沉积沉积在铜电极上,通过在170°C下粘合1分钟,实现了晶片级3D异质集成。通过电导率的空间映射观察到超稳电导率和热机械性能,功函数,力-距离曲线。关于NHC纳米层的表征,低温粘接,强大的腐蚀抑制,增强导电性,后端流程兼容性,和制造过程的减少,NHCCu/聚合物键合在3D异质集成方面提供了多方面的进展,表明NHCCu/聚合物键合可以用作未来3D垂直芯片架构的平台。
The commercialization of 3D heterogeneous integration through hybrid bonding has accelerated, and accordingly, Cu-polymer bonding has gained significant attention as a means of overcoming the limitations of conventional Cu-SiO2 hybrid bonding, offering high compatibility with other fabrication processes. Polymers offer robust bonding strength and a low dielectric constant, enabling high-speed signal transmission with high reliability, but suffer from low thermomechanical stability. Thermomechanical stability of polymers was not achieved previously because of thermal degradation and unstable anchoring. To overcome these limitations, wafer-scale Cu-polymer bonding via N-heterocyclic carbene (NHC) nanolayers was presented for 3D heterogeneous integration, affording ultrastable packing density, crystallinity, and thermal properties. NHC nanolayers were deposited on copper electrodes via electrochemical deposition, and wafer-scale 3D heterogeneous integration was achieved by adhesive bonding at 170 °C for 1 min. Ultrastable conductivity and thermomechanical properties were observed by the spatial mapping of conductivity, work function, and force-distance curves. With regard to the characterization of NHC nanolayers, low-temperature bonding, robust corrosion inhibition, enhanced electrical conductivity, back-end-of-line process compatibility, and fabrication process reduction, NHC Cu/polymer bonding provides versatile advances in 3D heterogeneous integration, indicating that NHC Cu/polymer bonding can be utilized as a platform for future 3D vertical chip architectures.