AVS 46th International Symposium
    Applied Surface Science Division Thursday Sessions
       Session AS-ThM

Paper AS-ThM5
Effect of Sputtering Gas on Cleaning Al-Based Intermetallics and the Determination of Surface Compositions based on Auger Analysis

Thursday, October 28, 1999, 9:40 am, Room 6A

Session: Real World Surface Analysis
Presenter: C.J. Jenks, Ames Laboratory
Authors: C.J. Jenks, Ames Laboratory
T.E. Bloomer, Ames Laboratory
M.J. Kramer, Ames Laboratory
J.W. Burnett, Iowa State University
D.W. Delaney, Ames Laboratory
T.A. Lograsso, Ames Laboratory
M.F. Besser, Ames Laboratory
D.J. Sordelet, Ames Laboratory
P.A. Thiel, Ames Laboratory
Correspondent: Click to Email
Argon is the typical gas of choice for sputtering single crystals in preparation for ultrahigh vacuum studies. However, the use of argon when cleaning Al-based intermetallics leads to preferential etching of Al. This can be a problem because of potential phase changes and the need for a consistent surface composition after annealing. We have examined the extent of this preferential etching as a function of ions/cm@super 2@ for helium, neon, argon, and krypton. The intermetallic substrate has a bulk composition of Al@sub 72.8@Pd@sub 18.6@Mn@sub 8.6@. We find for this material that the steady state Al concentration at the surface is about the same for all the sputtering gases examined. However, the number of ions/cm@super 2@ (which is related to time) depends on the sputtering gas used. Also discussed will be the determination of surface composition of Al-based intermetallics by Auger Electron Spectroscopy. For these materials, in particular, the sensitivity factors will differ greatly between the pure elements and the compound matrix because of changes in electron escape depth, electron backscattering, and atomic density. We find that the use of certain standards can lead to erroneous results.