**High Energy Focused Ion Beam Microscale Analysis and Modification of
Materials**

*G. A. Glass and W. A. Hollerman, Acadiana Research Laboratory,
University of Louisiana at Lafayette, P.O. Box 44210, Lafayette, LA
70504-4210*, http://www.louisiana.edu/Research/ARL.

** Abstract Number: 99**

**Figure 1. **Nuclear Microprobe Principles

The University of Louisiana at Lafayette's (UL Lafayette) Acadiana
Research Laboratory utilizes ion accelerators for multi-disciplinary
research in physics, materials science, engineering and environmental
science; providing the tools for a wide variety of materials analysis
and modification techniques. A 1993 U.S. Department of Energy EPSCoR
grant involving five Louisiana universities and several additional
grants from the Louisiana Board of Regents have been used to expand and
enhance the ion beam research capabilities at UL Lafayette while
accomplishing research goals. The ion beam research capabilities of the
laboratory have been under development since 1990 and a wide variety of
materials analysis techniques using singly or multiply charged ions high
energy (200 keV - 10 MeV) ion beams are presently available. These
include:

**Figure 2.** Micro-PIXE scan of (a) yttrium in Eu-doped Y~2~O~2~S fluor
particles, and (b) silicon in the glass slide supporting the fluor
material. The appearance of "holes" in the silicon scan is caused by
reduced production and detection of silicon x-rays through fluor
particles**.**

-   particle induced x-ray emission spectroscopy (PIXE) to provide trace
    element compositional analysis as low as 1 part per million,

-   particle induced gamma-ray emission spectroscopy (PIGE),

-   nuclear resonance scattering (NRS),

-   Rutherford backscattering spectrometry (RBS),

-   Rutherford forward scattering spectrometry (RFS), and

-   time-of-flight elastic recoil detection analysis (TOF-ERDA).

**Figure 4. **STIM energy loss images of copper calibration grid (12.5
µm spacing) (a) thick and (b) thin sections, obtained with 2 µm x 2 µm,
2 MeV proton beam.

**Figure 3.** Secondary electron images produced by 2 MeV, 2 µm x 2 µm
proton beam on 250 µm diameter copper wire; (a) 500 µm scan size, (b)
scan of boxed area in (a).

However, the development of the nuclear microprobe system represented in
Figure 1 and a continually increasing number of nuclear microscopy
analysis and modification techniques provide a genuinely unique ability
to study surfaces, coatings, and interfaces between substrates and thin
coatings with spatial resolutions less than 1 µm. Presently nuclear
microscopy techniques include 2-D scanning secondary electron imaging,
2-D elemental mapping using micro-PIXE, scanning transmission ion
microscopy (STIM), ion micro-implantation and ion microfabrication.
Operational design of a 3-D profiling system utilizing RBS is presently
in progress while additional techniques, heretofore not available on any
comparable microprobe system, are now being developed. Figure 2 shows
two micro-PIXE scans, obtained simultaneously, of a Eu-doped Y~2~O~2~S
fluor material on a glass substrate, illustrating the particle nature of
the fluor material. Figure 3 is an example of the secondary electron
imaging capability of the microprobe while the STIM images shown in
Figure 4 demonstrate how ion beam energy loss can be used to obtain thin
film density structure information.

**Acknowledgments: **Supported in part by the U.S. Department of Energy
and the Louisiana Board of Regents Support Fund under contracts
DOE/LEQSF (1993-95)-03, DE-FC02-91ER75669, LEQSF(1996-97)-ENH-TR-75 and
LEQSF (2000-2003)-39.