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 (Cu₂O, Cu^I) 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^II) 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.

中文翻译：

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对高频芯片间互连的铜环氧树脂接口的基本见解


需要未来的工艺和材料来实现芯片到芯片 （C2C） 数据速率为 50 GB/s 或更高的多芯片封装。由于集肤效应，这带来了一个根本性的挑战，趋肤效应加剧了高频下的信号传输损耗。我们的结果表明，与相对较薄的亚铜氧化物（Cu₂O、Cu）和胺官能硅烷附着力促进剂的光滑铜互连物将与环氧树脂电介质的界面附着力提高了近一个数量级。我们首次提出了 X 射线光电子能谱 （XPS） 和拉曼光谱在硅烷处理界面上形成 Cu（I）-O-Si 键的证据。因此，相对平滑的互连可以从减少蒙皮损失中受益，同时保持其机械完整性和可靠性。使用扫描电子显微镜 （SEM） 和俄歇电子能谱 （AES） 探讨了 Cu 与亚铜和铜氧化物 （CuO， Cu^II） 互连的失效机制。这些结果表明，与具有粘附促进剂的薄亚铜氧化物相比，铜氧化物和相对较厚的氧化亚铜界面都会导致界面相对较弱。