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

Paper AS-FrM1
ToF-SIMS Measurements of a Fluorocarbon-based Self-Assembled Monolayer on Si

Friday, November 4, 2005, 8:20 am, Room 206

Session: Practical Methods and Applications for Surface Analysis
Presenter: J.A. Ohlhausen, Sandia National Laboratories
Authors: J.A. Ohlhausen, Sandia National Laboratories
K.R. Zavadil, Sandia National Laboratories
Correspondent: Click to Email
Low surface energy coatings and films are needed to minimize stiction, high friction and wear of the oxide-terminated silicon-based MicroElectroMechanical Systems (MEMS) to ensure reliable device function. One common approach is to deposit self-assembled monolayer (SAM) films containing reactive silane headgroups and low energy pendant chains to cover the complex structures used in MEMS devices. The composition of these films is difficult to characterize and quantify (a property or quality is quantified composition, an aspect of structure, etc.). Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is an ideal tool for characterizing these types of films, however interpretation of the spectral data generated is complex and challenging. We are using the combination of X-ray Photoelectron Spectrometry (XPS) and ToF-SIMS to detect and quantify several candidate fluorocarbon-based SAMS on Si coupons and on MEMS devices. Unexpected fragmentation caused by the interaction of the primary ion beam with the fluorocarbon chain in contact with the Si surface creates ions whose presence are not intuitive. We can account for these ion fragments and use them to aid in quantifying the film composition. Our methods include the use of coverage-dependent fragmentation signatures along with the application of multivariate statistical techniques to establish the co-variance in these signatures. The fragmentation seen in this system along with the quantification method we used will be presented. @FootnoteText@ Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under contract DE-AC04-94AL85000.