Absorbed-specimen current imaging implementation and characterization in nano-prober for resistive interconnects isolation in 45-nm silicon-on-insulator microprocessors

Absorbed-specimen current imaging forms an image based on the electron current signal absorbed by the specimen when the primary electron beam scans across the specimen in the scanning electron microscopy (SEM). This method combined is mainly used to localize resistive or open contact/via sites in a multi-layer silicon-on-insulator (SOI) microprocessor chip. The major benefit of absorbed-current imaging is the isolation of buried interconnect defects beneath the surface layer. We successfully implemented absorbed-current imaging in a nano-prober system and performed detailed characterization of parameters influencing the absorbed current. The absorbed-specimen current imaging method is validated using intentionally shorted interconnects.