Nuclear Reaction Analysis for H, Li, Be, B, C, N, O and F with an RBS Completeness Check

(1) Physics Department, University at Albany SUNY,  Albany, NY 12222, USA
(2) Logic Technology Development, Intel Corporation, Hillsboro, OR 97124, USA
(3) Department of Physics, University of Missouri–Kansas City, Kansas City, MO 64110, USA
(4) Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI- 00014, Finland
(5) Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, Oslo, N-0315, Norway
(6) Solid State Division, Oak Ridge Nantional Laboratory, Oak Ridge, TN 37831 USA
(7) Dept. of Electrical and Computer Engineering, Univ. of  Texas, Austin, Texas 78758

15N nuclear reaction analysis for hydrogen is combined with 1.2 MeV deuteron induced nuclear reactions which provide a simultaneous analysis for Li, Be, B, C, N, O and F.  The energy dependence of these 1.2 MeV deuteron induced nuclear reactions has been measured and used to correct for the energy loss of the incident deuteron beam in the film being analyzed.  After the nuclear reaction analysis is completed, a conventional 2 MeV He RBS measurement is made.  All three measurements are needed for a self-consistent analysis:  the complete film composition is needed both to interpret the 15N nuclear reaction data and to apply the deuteron energy loss correction.  The composition is determined by a self-consistent analysis of the light element nuclear reaction data (both 15N and deuteron) combined with an RBS analysis of any heavy element (typically Si) present in the film. This composition is used to make RUMP simulation with no adjustable parameters of the complete RBS spectrum. Comparison of this simulated RBS spectrum with the measured spectrum provides a check that there are no major undetected components in the film, and, in some cases, a check that the film has uniform composition vs depth.  This procedure has been used to analyze several hundreds of thin films with a wide variety of compositions and has proven to be robust. All measurements are made using the same scattering chamber typically loaded with 14 samples with the bombarding beam changed from 15N++, to 1.2 MeV deuterium, to 2 MeV 4He+.  While some laboratories are reluctant to run deuteron beams, our experience with 50 namp 2.4 MeV D2+ beams, radiation is not a significant issue.