Microtextural Characterization and Orientational Mapping of Polycrystalline Thin Films Using TEM Dark Field Imaging Through an Annular Objective Aperture

Abstract

Several methods have been applied to the texture characterization of polycrystalline films, including X-ray diffraction and several SEM and TEM techniques. Few of these techniques combine high spatial resolution with the ability to characterize large sample areas in a short time. We have fabricated annular objective apertures for the TEM, extending earlier work of Heinemann and Poppa, to characterize the orientation and size of grains within polycrystalline thin films. This procedure is similar to conical dark field imaging which has been shown to provide microtextural information over large areasApertures were fabricated using a FEI FIB-200 focused ion beam (FIB) workstation. Bitmap templates of apertures were created using Adobe Illustrator™ and converted to stream files. These stream files were then used to controllably cut annular apertures into an existing platinum JEOL aperture strip with a 30 keV Ga+ FIB. The apertures were then placed in the objective aperture drive of a JEOL 2000FX transmission electron microscope and TiN thin films were imaged in bright- and dark-field imaging modes.