New observation of nanoscale interfacial evolution in micro Cu-Al wire bonds by in-situ high resolution TEM study

作者：Xu Hui^*; Qin Ivy; Clauberg Horst; Chylak Bob; Acoff Viola L

来源：Scripta Materialia, 2016, 115: 1-5.

DOI：10.1016/j.scriptamat.2015.12.025

• Copper aluminum
• Topic
• Wire bond
• Interfacial structure
• Intermetallic compounds
• In-situ TEM

Three types of interfacial nanostructure are identified in as-bonded Cu-Al bonds: (1) Cu/similar to 5 nm amorphous alumina layer/Al; (2) Cu/similar to 20 nm CuAl2 intermetallic particle/Al; and (3) Cu/Al. During annealing, in the areas of latter two types where alumina layer is fragmented, Cu9Al4 and CuAI form as second and third intermetallic layers, and grow vertically and fast together with initial CuAl2. In the area of first type where alumina layer is present, CuAl2 grows laterally and slowly via Cu diffusion through intermetallic compounds in the neighboring area where alumina is broken to reach Al. Cu-Al interdiffusion is dominated by Cu diffusion.

• 出版日期2016-4-1