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 Y2O2S 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 Y2O2S 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.