Abstract Reactive bonding using nanoscale multilayers based on the high specific surface/interface energy is a promising low-temperature and low-pressure wafer-bonding process. Herein, Si wafers were bonded using nanoscale Ag/Cu multilayers in N2 or the ambient atmosphere. A flawless joint composed of Ag-rich and Cu-rich face-centered cubic (fcc) phases was achieved in N2 with 22.2 MPa shear strength. However, a peculiar “fcc-(Ag)+voids/Cu2O/fcc-(Ag)+voids” three-layer sandwich structure with 11.1 MPa shear strength was formed due to significant out segregation of Cu toward the bonding-interface in the ambient atmosphere. The bonding mechanism and the role of oxygen were unveiled based on CALPHAD (CALculation-of-PHAse-Diagram) thermodynamic modeling.

中文翻译：

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使用纳米级 Ag/Cu 多层膜进行反应性晶圆键合

摘要 使用基于高比表面/界面能的纳米级多层反应键合是一种很有前途的低温低压晶圆键合工艺。在此，Si 晶片是在 N2 或环境气氛中使用纳米级 Ag/Cu 多层键合的。在 N2 中实现了由富银和富铜面心立方 (fcc) 相组成的完美接头，剪切强度为 22.2 MPa。然而，由于周围环境中Cu向键合界面的显着偏析，形成了一种奇特的“fcc-(Ag)+voids/Cu2O/fcc-(Ag)+voids”三层夹层结构，剪切强度为11.1 MPa气氛。基于CALPHAD（CALculation-of-PHAse-Diagram）热力学模型揭示了键合机制和氧的作用。