US 8,785,850 B2 · Charging of a hole-free thin film phase plate

Abstract

New methods for phase contrast imaging in transmission electron microscopy use the imaging electron beam itself to prepare a hole-free thin film for use as an effective phase plate, in some cases eliminating the need for ex-situ fabrication of a hole and reducing requirements for the precision of the ZPP hardware. The electron optical properties of the ZPP hardware are modified primarily in two ways: by boring a hole using the electron beam; and/or by modifying the electro-optical properties by charging induced by the primary beam. Furthermore a method where the sample is focused by a lens downstream from the ZPP hardware is disclosed. A method for transferring a back focal plane of the objective lens to a selected area aperture plane and any plane conjugated with the back focal plane of the objective lens is also provided.

Claims7

Dependent claims

A method of phase contrast imaging with a transmission electron microscope TEM including a sample holder, an objective lens assembly, one or more intermediate lenses, and an object plane, wherein the method comprises:

placing a hole-free thin film at a back focal plane of the objective lens assembly, or at a plane conjugate thereto;
preparing the hole-free thin film for phase contrast imaging using an electron beam having at least a component thereof focused to a small area on the hole-free thin film at a center of the electron beam;
and
subsequently imaging a sample in the sample holder by focusing unscattered waves of the electron beam onto a small area on the hole-free thin film, while scattered waves are distributed across the hole-free thin film to impart a phase offset between the scattered and unscattered waves.

1 more element

Dependencies are inferred from the claim text.

Charging of a hole-free thin film phase plate

Life of this patent

Charging of a hole-free thin film phase plate

Life of this patent

Abstract

Claims7