Breaking a nominal through-silicon-via (TSV) and forming a clean cross-section

A method for breaking a through-silicon-via (TSV) and forming a clean cross-section is investigated. We use focus-ion-beam (FIB) and diamond saw to create the notches that induce the crack passing through TSV precisely. Bending the sample with two side notches of diamond saw revealed the notch of diamond saw may cause the breaking failure. Only one side notch of silicon sample is an accurate breaking through a TSV with about 1 um diameter. The fracture surface indicates where the cracks originated from and which notch dominates the cross-section of TSV. The Auger electron spectra show the Ga contaminant spreading less than 300 nm from a FIB notch that may provide the information for the nano-scale accuracy of the breaking.