| AVS 59th Annual International Symposium and Exhibition | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuP |
| Session: | Applied Surface Science Poster Session |
| Presenter: | J.A. Ohlhausen, Sandia National Laboratories |
| Authors: | J.A. Ohlhausen, Sandia National Laboratories M.J. Rye, Sandia National Laboratories P.G. Kotula, Sandia National Laboratories J.R. Michael, Sandia National Laboratories T.J. Garino, Sandia National Laboratories |
| Correspondent: | Click to Email |
We have developed a method to create a cross-section of small samples for Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) utilizing a Focused Ion Beam (FIB) approach. Using this method, a nearly ideal surface for elemental and molecular analysis of the cross-sectional surface is produced, thus providing complimentary information to other microanaltical techniques like scanning elelctron microscopy (SEM) and scanning transmission electron microscopy (STEM).
FIB is commonly used to create cross sections for SEM and STEM imaging and analysis. Benefits of this technique include controlled extraction area and high spatial resolution. Unfortunately, elemental analyses in the SEM and STEM are not sensitive to low-Z elements and have detection limits that may prevent the detection of some species of interest. Although ToF-SIMS produces lower spatial resolution (~200nm), it has excellent low-Z sensitivity and has detection limits in the ppm to ppb range. Traditional FIB lift-out sections have been used as cross sections for ToF-SIMS analysis, but they are typically fragile and difficult to handle, thus complicating ToF-SIMS analysis. We have developed a method to create cross sections of particles and small fragments of material that can be analyzed in the “as cut / as mounted” condition. Samples are placed on a traditional SEM mount, and then coated with a conductive layer of AuPd. With the use of special mounts, a cross section that is parallel to the sample surface is milled in the FIB. The resulting samples are sturdy, allowing the removal of the Ga implants by O2 sputtering. The cross sectioned sample can now be analyzed with ToF-SIMS. Using data from ZnO multi-grain particles, we will show that ToF-SIMS analysis of the cross section yields elemental and molecular information with low detection limits. Additionally, we will demonstrate that multivariate analysis of ToF-SIMS data acquired by this technique is complimentary to a FIB-STEM analysis.§Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.