Scanning ion microscopy with low energy lithium ions

Kevin A Twedt; Lei Chen; Jabez J McClelland

doi:10.1016/j.ultramic.2014.03.014

Scanning ion microscopy with low energy lithium ions

Ultramicroscopy. 2014 Jul:142:24-31. doi: 10.1016/j.ultramic.2014.03.014. Epub 2014 Apr 5.

Authors

Kevin A Twedt¹, Lei Chen², Jabez J McClelland³

Affiliations

¹ Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA; Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA.
² Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
³ Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. Electronic address: jabez.mcclelland@nist.gov.

PMID: 24751577
DOI: 10.1016/j.ultramic.2014.03.014

Abstract

Using an ion source based on photoionization of laser-cooled lithium atoms, we have developed a scanning ion microscope with probe sizes of a few tens of nanometers and beam energies from 500eV to 5keV. These beam energies are much lower than the typical operating energies of the helium ion microscope or gallium focused ion beam systems. We demonstrate how low energy can be advantageous in ion microscopy when detecting backscattered ions, due to a decreased interaction volume and the potential for surface sensitive composition analysis. As an example application that demonstrates these advantages, we non-destructively image the removal of a thin residual resist layer during plasma etching in a nano-imprint lithography process.

Keywords: Ion scattering; Laser-cooling; Nano-imprint lithography; Scanning microscopy.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.