A nanoscaled copper (Cu) line is subject to aggravated electromigration after prolonged use, and thus the use of ultrathin barrier/capping layer without degrading its electrical properties is increasingly needed. The aim of this study is to investigate the electromigration resistance of Cu interconnect strengthened by a self-assembled monolayer of (3-aminopropyl)trimethoxysilane (APTMS-SAM) and to develop an entirely wet chemically process for the fabrication of Cu lines. The Cu line with its bottom and sidewalls coated by an APTMS-SAM remains intact and yields the lowest resistivity of 1.80 μΩ-cm even after 500 C annealing. The resistance of the Cu line against electromigration is remarkedly strengthened by using the APTMS-SAM as a molecular thick barrier due to a low relative diffusion rate of atoms under a constant current stressing, leading to an enhancement of thermal stability by at least 100 C. The depletion of Cu atoms of a bare Cu line is observed to start from its top area, suggesting surface diffusion is the dominating electromigration mechanism. The enhancement of the Cu interconnect encapsulated by an APTMS-SAM is thus proposed, which indeed serves as a barrier to strengthen the electromigration resistance and enhance the thermal stability of the nanoscaled Cu line.

纳米级铜（Cu）线在长时间使用后会发生严重的电迁移，因此越来越需要使用超薄阻挡/覆盖层而不降低其电性能。本研究的目的是研究由（3-氨基丙基）三甲氧基硅烷（APTMS-SAM）的自组装单层增强的铜互连的抗电迁移性，并开发用于制造铜线的完全湿化学工艺。底部和侧壁涂有 APTMS-SAM 的 Cu 线保持完整，并产生 1.80 μ的最低电阻率Ω-cm 甚至在 500 C 退火后。由于在恒定电流应力下原子的相对扩散率较低，因此使用 APTMS-SAM 作为分子厚势垒可显着增强 Cu 线对电迁移的抵抗力，从而使热稳定性提高至少 100 C。观察到裸铜线的铜原子耗尽从其顶部区域开始，表明表面扩散是主要的电迁移机制。因此提出了增强由 APTMS-SAM 封装的 Cu 互连，这确实作为屏障来增强抗电迁移性并提高纳米级 Cu 线的热稳定性。