Method of three-dimensional atomic imaging
AssigneeUniversity of Wisconsin - Milwaukee
InventorDavid S. Y. Tong
Life of this patent
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Abstract
A method of three-dimensional imaging of the atomic environment of atoms near the surface of the sample involves forming a localized source electron diffraction pattern, detecting the intensity of the distribution of the pattern, and generating data corresponding to the intensity distribution. The intensity data is normalized and corrected for a phase shift error to produce data corresponding to a hologram. The process may be repeated at a several predetermined emitted electron energies, and the data at each energy is combined to yield a composite image intensity having improved resolution. The method of the invention can provide a lenseless electron microscope having a resolution better than one angstrom and which overcomes distortions caused by multiple scattering.
Claims14
In a method for three-dimensional imaging of the atomic environment of a sample, including the steps of directing a beam against said surface to form a localized source electron diffraction interference pattern, detecting the intensity distribution of said pattern, calculating numerical image intensity data corresponding to said intensity distribution, and reconstructing the interference data to form a pattern indicating the location of a scatterer atom on said surface relative to an associated emitter atom on said surface, the improvement which comprises:
- phase shift-correcting the data using a function P.sub.i (k) dependent on the polar angle between the emitter atom and a scatterer atom i.
A method for three-dimensional imaging of the atomic environment of a sample, comprising the steps of:
- (a) directing a beam against said surface to form a localized source electron diffraction interference pattern;
- (b) detecting the intensity distribution of said pattern;
- (c) calculating numerical image intensity data corresponding to said intensity distribution;
- (d) normalizing the intensity data;
- (e) phase shift-correcting the normalized data;
- and
- (f) reconstructing the corrected interference data to form an image indicating the location of a scatterer atom on said surface relative to an associated emitter atom on said surface.
An apparatus for three-dimensional imaging of the atomic environment of a sample, comprising:
- means for directing a beam against said surface to form a localized source electron diffraction interference pattern;
- means for detecting the intensity distribution of said pattern;
- means for calculating numerical image intensity data corresponding to said intensity distribution;
- means for normalizing the intensity data;
- means for phase shift-correcting the normalized data;
- and
- means for reconstructing the corrected interference data to form an image indicating the location of a scatterer atom on said surface relative to an associated emitter atom on said surface.
Dependencies are inferred from the claim text.