Eur. Phys. J. AP 11, 147-151 (2000)
https://doi.org/10.1051/epjap:2000155

Surface imaging by an ion probe scanning

¹ Laboratoire de Physique des Solides, Université de Paris-Sud, CNRS, 91405 Orsay Cedex, France
² CSNSM, 91405 Orsay Cedex, France

Corresponding author: wang@lps.u-psud.fr

Received: 30 July 1999
Revised: 1 March 2000
Accepted: 13 July 2000
Published online: 15 August 2000

Abstract

We describe the realization of an ultrahigh vacuum scanning ion beam apparatus. The ion gun is based on the principle of field emission from a liquid gallium film wetting a sharp needle. The beam can be focused to a probe spot with a diameter less than 40 nm. The gun is fixed to an ultrahigh vacuum chamber, and is driven by a digital scanning device that works at variable frequency. The video image is built from the outgoing electrons resulting from the ion beam impacts. We describe the setup and discuss the relation between the ion probe current and the scanning speed. Specific applications to surface imaging are presented.