AVS 58th Annual International Symposium and Exhibition
    Thin Film Division Monday Sessions
       Session TF-MoM

Paper TF-MoM9
Three Dimensional Reciprocal Space Measurements by X-ray Diffraction using Linear and Area Detectors: Application to Texture and Defect Determination in Oriented Thin Films and Nanoprecipitates

Monday, October 31, 2011, 11:00 am, Room 107

Session: Thin Films: Growth and Characterization I
Presenter: Simon Gaudet, École Polytechnique de Montréal, Canada
Authors: S. Gaudet, École Polytechnique de Montréal, Canada
S. Lambert-Milot, École Polytechnique de Montréal, Canada
P. Desjardins, École Polytechnique de Montréal, Canada
K. Dekeyser, Ghent University, Belgium
C. Detavernier, Ghent University, Belgium
J.L. Jordan-Sweet, IBM T.J. Watson Research Center
C. Lavoie, IBM T.J. Watson Research Center
Correspondent: Click to Email
Very thin films grown or deposited on oriented substrates are often composed of highly oriented phases. Traditional x-ray diffraction approaches, scanning only limited portions of the reciprocal space, can fail to characterize some phenomenon occurring in those thin films. We developed an approach for the fast and efficient measurement of complete volumes of the reciprocal space by x-ray diffraction using linear and area detectors. In this presentation, we show how it allowed a detailed understanding of the solid-state thin film reaction to form contacts on transistors and of the growth of magnetic nanoprecipitates by metalorganic vapor-phase epitaxy. We first explain the procedures and scan strategies required for transforming raw scattering data into three-dimensional maps of the reciprocal space, and we present a complete open source software package for advanced data processing, analysis, and visualization. Case studies, chosen to highlight the overall capabilities of the technique, are then introduced. First, thermal diffuse scattering from a monocrystalline Si substrate is characterized. The presence of lines linking diffraction peaks in reciprocal space reflects the interaction of the x-ray beam with the phonon spectrum of the monocrystal. Second, a detailed investigation of texture in multiphase thin layers permits to reveal the unambiguous presence of fiber, axiotaxial, and epitaxial components in extremely oriented films. The visualization of the entire reciprocal space allowed us to identify unexpected metastable phases that could not be deduced or observed from measurements carried out in the Bragg-Brentano geometry. Finally, we present an investigation of defects in two thin film systems: planar defects in nickel silicide layers formed by solid-state reactions and microtwins in a GaP matrix containing coherent MnP precipitates. In summary, the systematic acquisition of significant volumes of the reciprocal space allows for the observation of behaviors that could otherwise remain undetected when restricting the analysis to typical measurement scans.