| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Thin Films | Tuesday Sessions |
| Session TF-TuM |
| Session: | Interfaces in Multilayers & Nanocomposites |
| Presenter: | Alberto Herrera-Gomez, CINVESTAV-Unidad Queretaro, Mexico |
| Authors: | A. Herrera-Gomez, CINVESTAV-Unidad Queretaro, Mexico O. Ceballos-Sanchez, CINVESTAV-Unidad Queretaro, Mexico M. Vazquez-Lepe, Universidad de Guadalajara T. Duong, Texas A&M University R. Arroyave, Texas A&M University A. Sanchez-Martinez, CINVESTAV-Unidad Queretaro, Mexico F. Espinosa-Magaña, Cimav-Unidad Chihuahua |
| Correspondent: | Click to Email |
The electrical performance of InGaAs-based MOS structures is affected by post deposition annealing. A proper characterization of the structural alterations associated with the degradation of the interface and electrical properties is important for understanding failure mechanisms [1]. While most of the results are focused in the control of interfacial passivation [2], phenomena such as diffusion of atomic species from the substrate has not been as widely examined. The samples employed in this study were TiN/high-k/InGaAs MOS structures with different thermal treatments. X-ray spectroscopy (XPS) studies revealed the appearance of an indium peak induced by annealing. Through a robust methodology based on angle-resolved XPS, it was found that the new peak is related to diffusion of indium through the dielectric into the metallic layer. This is the case when the high-k material is alumina [3], hafnia [4] and zirconia [5]. The transport of gallium is only patent in the case of hafnia and zirconia [4,5]. The structure of the samples was characterized employing the MultiLayer Method [6] and the experimental methodology described in Reference 7. Once the structure (thickness and composition) of the various layers constituting the nanofilms were assessed, it was possible to generate the expected angular behavior of the XPS signal from the indium peak under different scenarios. By employing this “scenarios” approach it was possible to robustly show the diffusion phenomenon and to quantify the amount of transported mass. These results, together with density function theory (DFT) calculations, allowed for the assessment of the activation energy for the diffusion of indium through the high-k dielectrics. It was surprising to find that, for all three dielectrics, the transport activation energy of indium is around 0.8 eV.
[1] R. V. Galatage et al. Appl. Phys. Lett. 99, 172901 (2011).
[2] S. A. Suleiman et al. Electrochem. Solid-State Lett. 13, H336–H338 (2010).
[3] O. Ceballos-Sanchez, A. Sanchez-Martinez, M. O. Vazquez-Lepe, T. Duong, R. Arroyave, F. Espinosa-Magaña, and A. Herrera-Gomez, J. Appl. Phys. 112, 053527 (2012).
[4] A. Sanchez-Martinez, O. Ceballos-Sanchez, M.O. Vazquez-Lepe, T. Duong; Arroyave, R; Espinosa-Magana, F; Herrera-Gomez, A. J. Appl. Phys. 114, 143504 (2013).
[5] O. Ceballos-Sanchez, E. Martinez, A. Herrera-Gomez. Submitted to Appl. Phys. Lett.
[6] http://www.qro.cinvestav.mx/~aherrera/reportesInternos/arxpsAnalysisSharpIntefaces.pdf.
[7] A. Herrera-Gomez, F.S. Aguirre-Tostado, P.G. Mani-Gonzalez, M. Vazquez-Lepe, A. Sanchez-Martinez, O. Ceballos-Sanchez, R.M. Wallace, G. Conti and Y. Uritsky. J. Elec. Spec. Rel. Phen. 184, 487 (2011).