1] Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan [2] Promotion Center for Global Materials Research, National Cheng Kung University, Tainan 70101, Taiwan [3] Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 70101, Taiwan.
Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Sci Rep. 2014 Apr 2;4:4557. doi: 10.1038/srep04557.
Au-Ge alloys are promising materials for high-power and high-frequency packaging, and Ni is frequently used as diffusion barriers. This study investigates interfacial reactions in Au-12Ge/Ni joints at 300 °C and 400 °C. For the reactions at 300 °C, typical interfacial morphology was observed and the diffusion path was (Au) + (Ge)/NiGe/Ni5Ge3/Ni. However, an interesting phenomenon--the formation of (Au,Ni,Ge)/NiGe alternating layers - was observed for the reactions at 400 °C. The diffusion path across the interface was liquid/(Au,Ni,Ge)/NiGe/· · ·/(Au,Ni,Ge)/NiGe/Ni2Ge/Ni. The periodic thermodynamic instability at the NiGe/Ni2Ge interface caused the subsequent nucleation of new (Au,Ni,Ge)/NiGe pairs. The thermodynamic foundation and mechanism of formation of the alternating layers are elaborated in this paper.
金-镓合金是高功率和高频封装的有前途的材料，而镍常被用作扩散阻挡层。本研究调查了 300°C 和 400°C 下 Au-12Ge/Ni 接头的界面反应。对于 300°C 的反应，观察到了典型的界面形态，扩散路径为（Au）+（Ge）/NiGe/Ni5Ge3/Ni。然而，对于 400°C 的反应，观察到了一个有趣的现象——形成（Au、Ni、Ge）/NiGe 交替层。界面上的扩散路径是液体/（Au、Ni、Ge）/NiGe/····/（Au、Ni、Ge）/NiGe/Ni2Ge/Ni。NiGe/Ni2Ge 界面处的周期性热力学不稳定性导致新的（Au、Ni、Ge）/NiGe 对随后形核。本文详细阐述了交替层形成的热力学基础和机制。
