Induced damages on CMOS and bipolar integrated structures under focused ion beam irradiation

Abstract

Focused ion beam used for failure analysis or repairing of ASICs degrades device performances by charging up the surface circuit. The influence of focused ion beam on device electrical performances has been studied to understand the behavior of basic test integrated circuits. We have performed measurements on test structures : MOS capacitors and transistors and bipolar transistors. Oxide trap filling and leakage current through the structures induce different failure mechanisms such as : threshold voltage shift in MOS transistors, deep depletion state in MOS capacitors and current gain decrease in bipolar transistors. A characterization of these effects and a first interpretation are proposed.