AVS 52nd International Symposium
    Applied Surface Science Friday Sessions
       Session AS-FrM

Paper AS-FrM10
Improving High Resolution AFM Images - When are Sharp Tips Worthwhile?

Friday, November 4, 2005, 11:20 am, Room 206

Session: Practical Methods and Applications for Surface Analysis
Presenter: C.F.H. Gondran, ATDF Inc., a subsidiary of SEMATECH
Authors: C.F.H. Gondran, ATDF Inc., a subsidiary of SEMATECH
D.K. Michelson, ISMI, a subsidiary of SEMATECH
Correspondent: Click to Email
Recently, AFM probes with sharper tips (1-2 nm radii of curvature) have become commercially available. This provides broad access to an opportunity to improve high-resolution images. Under the right circumstances, these improvements are very dramatic.@footnote 1@ However, in other instances, sharp tips offer limited benefits and the additional cost may not be justified. This study is designed to improve our understanding of the benefits of using sharp tips and to help determine when these benefits can be realized. Two-dimensional geometric models@footnote 2@ are used to evaluate the effect of tip shape on AFM images, roughness values, and power spectral density curves obtained for a variety of sample types. The effects of tip size are studied as a function of the sample's surface roughness, average feature size, average feature spacing, and surface feature shape. The results, particularly for roughness values, are not always intuitive. The simulated data are correlated to sample data obtained on films commonly used in research and development for semiconductor manufacturing: epitaxial Si, high-k, low-k, and barrier layer materials. These correlations are used to assess the value of sharp tips for the semiconductor industry. @FootnoteText@ @footnote 1@ D. Klinov, S. Magonov "True molecular Resolution in Tapping-Mode Atomic Force Microscopy with High-Resolution Probes," Applied Phys. Letts., 84(14) 2004, p. 2697.@footnote 2@ C. F. H. Gondran, D. K. Michelson "Sampling and Reference Considerations for Very High Resolution AFM Analysis," in Proc. 30th International Symposium for Testing and Failure Analysis, ASM International, Ohio, 2004 p. 357.