title: Resolution limits of secondary electron dopant contrast in helium ion and scanning electron microscopy.
abstract: As the miniaturization of semiconductor devices continues, characterization of dopant distribution within the structures becomes increasingly challenging. One potential solution is the use of the secondary electron signal produced in scanning electron (SEMs) or helium ion microscopes (HeIMs) to image the changes in electrical potential caused by the dopant atoms. In this article, the contrast mechanisms and resolution limits of secondary electron dopant contrast are explored. It is shown that the resolution of the technique is dependent on the extent of electrical potential present at a junction and that the resolution of dopant contrast can be improved in the HeIM after an in-situ plasma cleaning routine, which causes an oxide to form on the surface altering the contrast mechanism from electrical potential to material contrast.
authors: Department of Materials, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK. m.a.e.jepson@lboro.ac.uk
authors: Mark
authors: M
authors: Jepson
authors: Xiong
authors: X
authors: Liu
authors: David
authors: D
authors: Bell
authors: David
authors: D
authors: Ferranti
authors: Beverley
authors: B
authors: Inkson
authors: Cornelia
authors: C
authors: Rodenburg