title: Dark-field electron holography for the measurement of geometric phase.
abstract: The genesis, theoretical basis and practical application of the new electron holographic dark-field technique for mapping strain in nanostructures are presented. The development places geometric phase within a unified theoretical framework for phase measurements by electron holography. The total phase of the transmitted and diffracted beams is described as a sum of four contributions: crystalline, electrostatic, magnetic and geometric. Each contribution is outlined briefly and leads to the proposal to measure geometric phase by dark-field electron holography (DFEH). The experimental conditions, phase reconstruction and analysis are detailed for off-axis electron holography using examples from the field of semiconductors. A method for correcting for thickness variations will be proposed and demonstrated using the phase from the corresponding bright-field electron hologram.
authors.affiliation: CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse, France. hytch@cemes.fr
authors.forename: M J
authors.initials: MJ
authors.lastname: Hÿtch
authors.forename: F
authors.initials: F
authors.lastname: Houdellier
authors.forename: F
authors.initials: F
authors.lastname: Hüe
authors.forename: E
authors.initials: E
authors.lastname: Snoeck