Untitled - IAP/TU Wien - Technische Universität Wien

71st IUVSTA Workshop
A R XPS on Surface Pre-Treatments for LiNbO 3 SAW substrate
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The analysis of surfaces/interfaces and thin films is vital for the improvement of surface acoustic wave
(SAW) devices. Such modern devices are characterised by the trend to higher frequencies, power densities
and new applications. Therefore, a shrinking of the dimensions is necessary but hardly possible to achieve
with standard Al based metallisation due to increased stress-induced damaging (acoustomigration). Better
results can be obtained by highly textured metallisations which were recently developed [1,2]. In this context
an additional barrier interlayer is necessary and a pre-treatment of the substrate. Furthermore, a Variation of
the deposition parameters ar an additional heat treatment might be of great interest.
This work gives an overview about studies of the effect of surface preparation at LiNbO 3 for a Ta
deposition used as barrier material. A radio-frequent plasma and a focused ion beam are applied for surface
treatment; a dc-sputter process is used for the deposition of Ta. An e-beam evaporation system is used for the
mainly by means of X-ray photoelectron spectroscopy (XPS) directly coupled to a preparation chamber
(quasi in situ). Applying the angle-resolved XPS method (AR-XPS), in-depth information can be obtained
without sputtering using an improved mathematical approach [3-5].
Funding of the work by DFG (Grant No. .-#**:;#is acknowledged.
References
[1] H. Schmidt, S. Menzel, M. Weihnacht, R. Kunze, Ultrasonics Symposium 2001, IEEE (2001), vol. 1,
97-100
[2] M. Spindler, S.B. Menzel, C. Eggs, J. Thomas, T. Gemming, J. Eckert, Micro. Engn. 85 (2008),
2055-2058
[3] M. Kozlowska, R. Reiche, S. Oswald, H. Vinzelberg, R. Hübner, K. Wetzig, Surf. Interface Anal. 36/13
(2004) 1600
[4] P. J. Cumpson, J. Electron. Spectrosc. Relat. Phenom. 73/1 (1995) 25
[5] S. Oswald, M. Zier, R. Reiche, K. Wetzig, Surf. Interface Anal. 38/4 (2006) 590
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