本研究透過觀察鍍鈀銅線與4N銅線接點於各種可靠度測試後，其界面反應之情形，探討抗氧化金屬鈀層於銅線製程界面反應之影響。
藉由WDS及EPMA 元素分佈分析，發現在未經可靠度測試之前， Pd原子主要分佈在接點內部，並於內部呈現對稱的雙圓弧形帶狀分布。另外，在銅線接點表面及界面處也有觀察到Pd原子的分佈。
經過可靠度測試後，Pd原子似乎會往Cu/Al接合界面方向擴散，並於界面處會形成一層 Pd-Cu 的固溶體層。當Cu-Al IMC成長時，此固溶體層在界面處，會有類似於擴散組障層(Diffusion barrier)的效果，影響銅鋁之間的交互擴散。這個現象會導致鍍鈀銅線接點的Cu-Al IMC生成速度慢於4N純銅線接點，並可能影響界面反應生成特定的IMC相。而較慢的Cu/Al IMC生長速度及特定的IMC相，有助於避免接合界面處裂縫的生成及提升接點接合性質，所以銅線上的抗氧化金屬鈀層對於改善接合可靠度性質有正面的助益。

The influence of oxidation-resistant palladium on the interfacial reactions of copper wire bonding at various reliability tests was investigated in this study.
In the as-bonded state, Pd was mainly distributed within the ball joint, forming two symmetrical curved bands near the Cu/Al interface; there were still some Pd atoms located at the surface of ball joints. During the reliability tests, Pd diffused from the inner portion of Pd-Cu ball toward the bond interface, and the Pd-Cu solution layer was formed near the bond interface. The Pd-Cu solid solution layer may act as a diffusion barrier to reduce the IMC growth rate by affecting the interdiffusion between Cu and Al. This phenomenon may lead to the slower Cu/Al IMC growth rate and thinner IMC thickness in Pd coated copper wires as compared with 4N copper wires. FIB studies show that Continuous cracks caused by stress were formed at the bond interface for 4N copper wires after PCT and THT tests; however, there was no crack for Pd-coated copper wires. During aging, the Pd-Cu solid solution layer affected the interdiffusion of Cu and Al and may dominate the IMC formation. This should contribute to the fact that the Pd-coated copper wires showed better bonding reliability than the 4N copper wires in copper wire bonding.

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