Localization of Electrically Active Extended Defects in GaN Using a DualBeam FIB

The Dual Focused Ion Beam (DFIB has been used to expose electrical fields associated with the charge of electrically active extended defects (ED) – (e.g. threading dislocations - TDs) in GaN structures. The localized electrical fields above electrically active defects in piezoelectric materials are shown to capture sputtered low energy ions, turning them back toward the surface and redepositing them on top of defects (TDs), forming Gallium-rich islands. This “Ga droplet” decorates EDs and significantly simplifies the process of locating EDs for TEM sample preparation and analyses. The size and shape of the Ga islands is correlated with the accumulated piezoelectric charge density at the EDs.