Physical Evidence Supporting the Electrical Signature of SEGR on Thin Vertical Oxides

Analysis techniques on a 90 nm deep trench capacitor have provided the physical evidence for a heavy ion induced single event gate rupture (SEGR). The trench capacitor is from a 90 nm bulk complementary metal oxide semiconductor technology and is used for the reduction of single event upsets. SEGR damaged trench oxides are identified via a voltage contrast technique using a focused ion beam. The focused ion beam was used to delayer and expose the deep trenches. A wet chemical etch was used to identify the location of the SEGR leakage path. The oxide rupture location was observed at the top of the deep trench capacitor.