title: Effective removal of Ga residue from focused ion beam using a plasma cleaner.
abstract: Samples prepared using the focused ion beam (FIB) inevitably contain the surface damage induced by energetic Ga+ ions. An effective method of removing the surface damage is demonstrated using a plasma cleaner, a device which is widely used to minimize the surface contamination in scanning transmission electron microscopy (STEM). Surface bombardment with low-energy Ar+ ions was induced by biasing the sample immersed in the plasma source, so as to etch off the surface materials. The etch rates of SiO2, measured with a bias voltage of 100-300 V, were found to vary linearly with both the time and bias and were able to be controlled from 1.4 to 9 nm/min. The removal of the Ga residue was confirmed using energy dispersive spectroscopy (EDS) after the plasma processing of the FIB-prepared sample. When the FIB-prepared sample was processed via plasma etching for 10 min with a bias of 150 V, the surface Ga damage was completely removed.
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, San 56-1, Sillim 9-dong, Gwanak-gu, Seoul 151-744, Republic of Korea.
authors.forename: Dong-Su
authors.initials: DS
authors.lastname: Ko
authors.forename: Young Min
authors.initials: YM
authors.lastname: Park
authors.forename: Sung-Dae
authors.initials: SD
authors.lastname: Kim
authors.forename: Young-Woon
authors.initials: YW
authors.lastname: Kim