Issue
EPL
Volume 85, Number 4, February 2009
Article Number 46001
Number of page(s) 4
Section Condensed Matter: Structural, Mechanical and Thermal Properties
DOI http://dx.doi.org/10.1209/0295-5075/85/46001
Published online 16 February 2009
EPL, 85 (2009) 46001
DOI: 10.1209/0295-5075/85/46001

Dopant contrast in the helium ion microscope

M. A. E. Jepson1, B. J. Inkson1, C. Rodenburg1 and D. C. Bell2

1   Department of Engineering Materials, The University of Sheffield - Sheffield, S1 3JD, UK, EU
2   School of Engineering and Applied Sciences and the Center for Nanoscale Systems, Harvard University Cambridge, MA 02138, USA

m.jepson@sheffield.ac.uk

received 24 November 2008; accepted in final form 25 January 2009; published February 2009
published online 16 February 2009

Abstract
Due to miniaturisation of semiconductor devices, there is an increasing need for nanoscale characterisation of dopant distributions. Scanning electron microscopy (SEM) has been identified as a potential technique to fulfil this need, providing that a small enough probe size (~ 0.1 nm) could be achieved. Probes of this size are not possible in a low-voltage scanning electron microscope but a He-ion beam can be focussed to probe sizes as small as 0.25 nm; a significant improvement over that attainable in the SEM. This paper presents results from the first use of helium ion microscopy (HeIM) to examine dopant contrast in semiconductor materials. It was found that the spatial resolution is improved when compared to SEM and that the contrast mechanism has similarities making HeIM an ideal candidate for future 2-dimensional nanoscale dopant mapping.

PACS
68.37.Vj - Field emission and field-ion microscopy.
68.37.Hk - Scanning electron microscopy (SEM) (including EBIC).
61.72.uf - Ge and Si.

© EPLA 2009