AVS 47th International Symposium
    Magnetic Interfaces and Nanostructures Tuesday Sessions
       Session MI+NS+NANO 6-TuM

Paper MI+NS+NANO 6-TuM11
Evaluation of MFM for Probing Electromigration Processes

Tuesday, October 3, 2000, 11:40 am, Room 206

Session: Magnetic Imaging I
Presenter: R. Yongsunthon, University of Maryland
Authors: R. Yongsunthon, University of Maryland
J. McCoy, University of Maryland
E.D. Williams, University of Maryland
Correspondent: Click to Email
The study of electromigration in metals requires correlation of current densities with the evolution of defects in current-carrying lines. In principle, magnetic force microscopy (MFM) is an appropriate tool for this purpose. Most use of MFM has concentrated upon determining magnetic polarity across magnetic domain boundaries, rather than quantification of magnetic field variation. Such quantification is non-trivial, because the extended nature of the tip-sample interaction involves complicated factors such as coupling of the system geometry. To explore the MFM capability to yield reliable analysis, we are evaluating the MFM instrument response for known structures, such as lines containing defects of simple geometry. The instrumental response function is defined by tip parameters, such as tip magnetization and shape, which make predicting the response function impractical. However, it is possible to make meaningful relative quantification and calibration, by comparison with response from structures where the behavior is well understood. To analyze the data from such known calibration samples, the fields around the lines are numerically calculated and compared with deconvolution of the measured signal. Preliminary results suggest that meaningful relative quantification of the signal can be achieved to within 20% and that current variations can be detected to at least 10%. Continuing work to relate this to the limiting levels of current crowding that will be detectable is underway. (Work supported by NSF-MRSEC, grant# DMR 96-3252.