AVS 47th International Symposium
    Material Characterization Monday Sessions
       Session MC-MoM

Paper MC-MoM1
Valence Model Based Correction of Ultra Shallow Depth Profiles

Monday, October 2, 2000, 8:20 am, Room 207

Session: Depth Profiling
Presenter: O. Brox, University of Muenster, Germany
Authors: O. Brox, University of Muenster, Germany
D. Gehre, AMD Saxony Manufacturing GmbH, Germany
E. Zschech, AMD Saxony Manufacturing GmbH, Germany
A. Benninghoven, University of Muenster, Germany
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In recent years lateral and in-depth dimensions of microelectronic devices have shrunk by orders of magnitude. The reduction in depth scale was supported by the application of ultra low implantation energies of dopant materials. As a consequence a significant part of the implanted species is located in the uppermost monolayers. The entire thickness of the shallow implants used nowadays of less than 10 nm implanted in oxides with a thickness up to 3 nm complicates the establishment of quantitative SIMS depth profiles. Changing conditions regarding the oxidation state require corrections of the concentration- and depth scale. Distortions can occur also due to the very high peak concentrations (distinctly higher than 1%) resulting from the ultra low implantation energies and from contamination layers as hydrocarbons e.g. For all experiments we used TOF instruments, equipped with flexible gas ion sources and cesium sources (0.6 - 10 keV) for crater formation. Additional gas ion sources (Ar@super +@, 11 keV) have been applied for the analysis of the crater bottom. We have investigated the possibility to compensate the falsification caused by changes of the secondary ion yield in the transient region by applying a suitable correction procedure based on the so-called lattice valency model.@footnote 1@ The success of this correction will be demonstrated by a quantitative depth profile of a 10 keV As-implant into a 3 nm screening oxide. The sputter behavior of undefined organic contaminations as well as of well defined polymer overlayers has been investigated. Sputter yields, damage cross sections, and thermal desorption behaviors will be reported. They allow an estimation of possible depth scale distortions. . @FootnoteText@ @footnote 1@ C. Plog, L. Wiedmann, A. Benninghoven, Surf. Sci. 67 (1977) 565.