Park Junghyun, Dauda Monsuru, Bello Mustapha, Agbadan Ignace, Engler Anthony Christian, Williamson Jaimal M, Mathew Varughese, Park Sunggook, Flake John C
Gordon A. and Mary Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
Texas Instruments Incorporated, Dallas, Texas 75243, United States.
ACS Appl Mater Interfaces. 2025 Jan 8;17(1):2480-2490. doi: 10.1021/acsami.4c16414. Epub 2024 Dec 18.
Future processes and materials are needed to enable multichip packages with chip-to-chip (C2C) data rates of 50 GB/s or higher. This presents a fundamental challenge because of the skin effect, which exacerbates signal transmission losses at high frequencies. Our results indicate that smooth copper interconnects with relatively thin cuprous oxides (CuO, Cu) and amine-functional silane adhesion promoters improve interfacial adhesion with epoxy dielectrics by nearly an order of magnitude. For the first time, we present X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy evidence of Cu(I)-O-Si bond formation at silane-treated interfaces. Thus, relatively smooth interconnects can benefit from reduced skin losses while maintaining their mechanical integrity and reliability. Failure mechanisms of Cu interconnects with cuprous and cupric oxide (CuO, Cu) are explored using scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). These results indicate that both cupric oxides and relatively thick cuprous oxide interfaces lead to relatively weaker interfaces compared with thin cuprous oxides with adhesion promoters.
未来需要新的工艺和材料来实现芯片间（C2C）数据速率达到50GB/s或更高的多芯片封装。由于趋肤效应，这带来了一个根本性挑战，趋肤效应会加剧高频下的信号传输损耗。我们的结果表明，具有相对较薄的氧化亚铜（CuO、Cu）和胺官能硅烷粘合促进剂的光滑铜互连，可将与环氧电介质的界面粘合力提高近一个数量级。我们首次展示了在硅烷处理的界面处形成Cu（I）-O-Si键的X射线光电子能谱（XPS）和拉曼光谱证据。因此，相对光滑的互连可以在保持其机械完整性和可靠性的同时，受益于降低的趋肤损耗。使用扫描电子显微镜（SEM）和俄歇电子能谱（AES）研究了含氧化亚铜和氧化铜（CuO、Cu）的铜互连的失效机制。这些结果表明，与带有粘合促进剂的薄氧化亚铜相比，氧化铜和相对较厚的氧化亚铜界面都会导致相对较弱的界面。
