Artefacts in RBS analysis of laser treated surfaces

Abstract

Laser treatment of deposited films often result in globules on the surface which may influence the solute depth profiles, as measured by Rutherford backscattering spectrometry (RBS). We show that the globules generally have poor adhesion to the substrate and can be easily removed using techniques commonly employed for testing adhesion of thin films, such as a scotch tape test, or mild abrasion test using a cotton bud or tip of a soft wooden piece. The effectiveness of this approach is demonstrated for Zn films on Al (treated with a 12 ns fwhm Nd: glass laser pulse) and Sb films on Al (treated with a 100 ns fwhm CO 2 laser pulse). The solute depth profiles, both before and after removal of globules from the laser treated surfaces, have been measured by employing RBS of He + ions and dramatic differences between the two cases have been observed. Laser treated surfaces are also characterized by optical microscopy and the topography is correlated with the RBS depth profiles. Results are presented for laser heating and liquid phase diffusion analysis of the solute depth profiles obtained after scotch tape and abrasion tests.