Dark-field electron holography for the measurement of geometric phase

作者：Hytch M J^*; Houdellier F; Huee F; Snoeck E

来源：Ultramicroscopy, 2011, 111(8): 1328-1337.

DOI：10.1016/j.ultramic.2011.04.008

• Electron holography
• Dark-field electron holography
• Geometric phase
• Strain

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.

• 出版日期2011-7