Author_Institution :
Dept. of Mater. Sci. & Eng., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
The texture as well as epitaxial growth of intermetallic compounds (IMCs) are becoming important issues, due to increases in IMCs-solder ratios in the development of micro-bumping. (Cu, Ni)6Sn5 formed on Ni substrate didn´t simply grow in an unexpected manner, but did so, producing a spectacular morphology. Even in the presence of very few Ni atoms dissolved in (Cu, Ni)6Sn5, a strongly preferential orientation growth was still observed. The crystal orientation relationships between (Cu, Ni)6Sn5 and Ni was recognized as: (12̅0)(Cu, Ni)6Sn5||(11̅1)Ni; [001](Cu, Ni)6Sn5||[110]Ni, according to EBSD and TEM analysis. The outcome of this study explicitly demonstrates that the morphology of (Cu, Ni)6Sn5 is determined by the preferred orientation relationship with Ni, and therefore one could predict the morphological texture of (Cu, Ni)6Sn5, once the crystal orientations of Ni were known. Moreover, because a coherent interface between (Cu, Ni)6Sn5 and Ni was observed, this study also verified that no (Ni, Cu)3Sn4 IMCs had formed at the interface of (Cu, Ni)6Sn5/Ni.
Keywords :
annealing; copper alloys; crystal orientation; epitaxial growth; metallic epitaxial layers; nickel alloys; tin alloys; transmission electron microscopy; Cu6Sn5; Ni; Ni substrate; Ni6Sn5; TEM; annealing; crystal orientation; epitaxial growth; intermetallic compounds; texture; Annealing; Copper; Diffraction; Lattices; Morphology; Nickel; Substrates;