| AVS 62nd International Symposium & Exhibition | |
| Applied Surface Science | Monday Sessions |
| Session AS-MoM |
| Session: | Quantitative Surface Analysis: Obtaining Quantitative Information in the Face of Material Complexity and Morphology Influences |
| Presenter: | Jennifer Mann, Physical Electronics |
| Authors: | J.E. Mann, Physical Electronics J.F. Moulder, Physical Electronics S.R. Bryan, Physical Electronics J.S. Hammond, Physical Electronics |
| Correspondent: | Click to Email |
A successful XPS sputter depth profile should accurately identify layer thickness and composition of materials as a function of depth within film structures. In the case of inorganic thin films, monoatomic argon ion beam depth profiling continues to be the preferred choice despite issues with preferential sputtering, material migration, and chemical reduction that may occur during the sputter process to alter the apparent profile of the analyzed material [1-3].
The introduction of C60 cluster ion beam and argon gas cluster ion beam (GCIB) sputtering in recent years provided the capability of successful depth profiling of polymer and organic materials as well as thin film structures while preserving the stoichiometry and chemical structures [4,5].
Currently, there is great interest in establishing the viability of these cluster ion sources as an alternative to Ar+ ion beam sources for analyzing inorganic semiconductor and glass films, with particular interest in a possible improvement in the quantitative accuracy of the depth profile results compared to Ar+ depth profiling [6,7].
The XPS depth profile of a thin film of the semiconductor material Indium Gallium Zinc Oxide (IGZO) was acquired with Ar+, C60+ and GCIB ion guns. The film thickness and composition was characterized by RBS. Preferential sputtering of the In through the thin film depth profiles was observed with all three ion sources. The highest level of preferential sputtering of In was observed with the Ar+ source while the C60+ source produced a relatively constant composition through the depth profiles and the most consistent with the expected elemental composition. The sputter volume per incident ion, the resulting interface width and the sputter crater roughness for the three different ion sources was also evaluated.
Similar evaluations for additional thin film oxide samples will also be presented. The results for these comparative studies suggest that depending on the composition of the inorganic oxide thin films, cluster ion sources may provide superior quantitative depth profiling for inorganic oxide thin film samples as well as organic thin film samples.
References
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[2] R. K. Brow, J. of Vac. Sci. Technol. A, 1989, 7, 1673.
[3] V. Smentkowski, Prog. in Sur. Sci., 2000, 64, 1.
[4] T. Nobuta, T. Ogawa, J. of Mater. Sci., 2009, 44, 1800.
[5] C. M. Mahoney, Mass Spec. Rev., 2010, 29, 247.
[6] Y. Yamamoto, K. Yamamoto, Mater. Sci. Eng., 2011, 18, 022005.
[7] D. Kobayashi, Y. Yamamoto, T. Isemura, Sur. and Inter. Anal., 2013, 45, 113.