Abstract
A new essentially nondestructive cross-sectional method is described for measuring the individual thicknesses of multilayer YBa2Cu3O7 (YBCO) and SrTiO3 (STO) thin films using off-axis ion milling and the atomic force microscope (AFM). Since the ion-milling is done during routine patterning of a thin-film device and the AFM requires only a small area for imaging, no additional sample preparation is required. This is a significant improvement over traditional cross-sectional techniques which often require lengthy and destructive sample preparation. Also, there is no a priori reason that this technique would not be amenable to other multilayer thin-film systems.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
For example, C. Saloma, K. Matsuoka, and S. Kawata, Rev. Sci. Instrum. 67, 2072 (1996); A. Wasserman, D. J. Roth, R. Beserman, A. Hoffman, and K. Dettmer, Appl. Phys. Lett. 68, 3407 (1996).
For example, Chap. 17 of Electron Microscopy of Thin Crystals, edited by P. Hirsch, A. Howie, R. Nicholson, D. W. Pashley, and M. J. Whelan (R. E. Krieger Publishing Co., Inc., Malabar, FL, 1977).
For example, J. Gao and W. H. Wong, Physica C 251, 330 (1995); P. C. McIntyre, M. J. Cima, and A. Roshko, J. Cryst. Growth 149, 64 (1995); D. W. Moon and K. J. Kim, J. Vac. Sci. Technol. A 14, 2744 (1996).
J. A. Bardwell, E. M. Allegreto, B. Mason, L. E. Erickson, and H. G. Champion, Appl. Phys. Lett. 68, 2840 (1996).
J. Yoon and D. G. Ivey, J. Mater. Sci. Lett. 15, 551 (1996).
J. A. Switzer, C. J. Hung, B. E. Breyfogle, M. G. Shumsky, R. V. Leeuwen, and T. G. Golden, Science 264, 1573 (1994).
W. Denk and D. W. Pohl, Appl. Phys. Lett. 59, 2171 (1991).
A. J. Howard, A. G. Baca, and R. J. Shul, Appl. Phys. Lett. 68, 3353 (1996).
For example, C. L. Pettiette-Hall, J. A. Luine, J. Murduck, J. F. Burch, R. Hu, M. Sergant, and D. St. John, IEEE Trans. On Appl. Supercond. 5, 2087 (1995).
Different etching rates of different materials as a function of ionmilling angle can lead to different angles for each material along the etched edge.
The cross-sectional analysis feature of the AFM was also used to confirm the calculated thicknesses; however, it is difficult to distinguish the layer boundaries in this analysis mode.
After stripping the photoresist and cleaning with an O2 plasma, the edge was noticeably rougher, thus making the layers more difficult to resolve.
J. R. LaGraff, unpublished results.
No extra intralayer boundary in STO1 was observed by the TEM.
The STM, SEM, and TEM operate best with conductive or semiconductive samples which dissipate the electrons used in imaging. The AFM is a contact probe and only needs to be in physical contact with the surface to obtain an image, regardless of the electrical properties of the materials.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
LaGraff, J.R., Murduck, J.M. Local Cross-sectional Profiling of Multilayer Thin Films with an Atomic Force Microscope for Layer Thickness Determination. Journal of Materials Research 12, 1935–1938 (1997). https://doi.org/10.1557/JMR.1997.0263
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/JMR.1997.0263