Interface Toughness Evaluation With Specimens Fabricated by Focused Ion Beam for Micro Scale Devices and Packages

Capability of detecting local interface strength variation with 10 ! m scale resolution was investigated in reference to the interface between vapor-deposited gold (Au) and SiO₂ with a practically homogeneous strength. Uncertainties in the evaluation procedure were thoroughly examined, which was to be excluded from the apparent scatter of evaluation results. The intrinsic scatter of strength in a damascene Cu/SiN cap interface was successfully specified to be at least 2.45 J/m².