| AVS 55th International Symposium & Exhibition | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuP |
| Session: | Aspects of Surface Analysis Poster Session |
| Presenter: | S. Tougaard, University of Southern Denmark |
| Authors: | S. Tougaard, University of Southern Denmark S. Hajati, University of Southern Denmark |
| Correspondent: | Click to Email |
XPS energy spectra vary characteristically with the depth distribution of electron emitting atoms on the nano-scale. This is the basis for the by now well known and widely used method1 to non-destructively determine atomic depth distributions with nano-meter resolution by analysis of the inelastically scattered electrons associated with the XPS peak. A new algorithm which is suitable for automation was suggested recently.2 For each XPS signal, this algorithm determines the total amount of the corresponding atoms within the outermost ~ 10 nm and it also determines their depth distribution. The validity of the algorithm was demonstrated experimentally by comparison to more elaborate quantification methods.3 In addition, software that can automatically analyze several thousand spectra corresponding to the situation in XPS imaging is developed. The software produces nondestructively a 3-D image of the surface with nanometer depth resolution. The practical applicability for XPS imaging was recently demonstrated.4-5 As an example we have demonstrated a quantitative test4 of the algorithms ability to produce images of Ag taken from a series of samples with increasing thicknesses of plasma patterned Octadiene (2, 4, 6 and 8nm) on Ag substrates. The obtained images of the amount of silver atoms in the outermost few nano-meters of the samples were in good agreement with the nominal thicknesses. For a given sample, different sectioning of depth distributions of atoms were made which clearly prove the ability of the method for quantitative and nondestructive 3-D characterization of nano-structures. In ref [5], 3D images of thermally patterned oxidized silicon made through a photolithographic mask were produced and it was shown that 3-D images of the Si, O, and C atoms were complementary. In the talk we will summarize the technique and discuss its limitations and capabilities.
1S. Tougaard Surf. Interf. Anal. 26, 249 (1998)
2S. Tougaard, J. Vac. Sci. Technol. A21, 1081 (2003)
3S. Tougaard, J. Vac. Sci. Technol. A23, 741 (2005)
4S. Hajati, S. Coultas, C Blomfield and S. Tougaard, Surf. Interf. Anal. 40, 688 (2008)
5S. Hajati, J. Walton, N. Fairley, and S. Tougaard, Surf. Sci. (2008). In press.