Identification of Cu-Al intermetallic phases of copper wire bonding using TEM nano beam diffraction indexing technique

The paper shares the application of electron diffraction spot indexing to identify intermetallic phases in copper wire bond. Standard Scanning Transmission Electron Microscopy (STEM) technique with a converged electron probe was modified to produce parallel nano beam for forming electron diffraction spot patterns, CuAl(η
₂
)and CuAl
₂
(θ) phases in copper wire bond were identified by indexing the diffraction spots.