The present disclosure provides an electron beam device (500) for inspecting a sample (10) with an electron beam, comprising an electron beam source comprising a cold field emitter (100) for emitting an electron beam, electron beam optics for directing and focusing the electron beam onto the sample (10), and a detector device (540) for detecting secondary charged particles generated by impingement of the electron beam on the sample (10). The cold field emitter (100) includes an emitter tip (110), a base arrangement (120) configured for supporting the emitter tip (110) and comprising a first base element (122) and a second base element (124), and a filament (130) having at least a first filament portion (132) and a second filament portion (134) attaching the emitter tip (110) to the base arrangement (120), wherein the first filament portion (132) extends between the emitter tip (110) and the first base element (122) and the second filament portion (134) extends between the emitter tip (110) and the second base element (124), wherein a length (L) of each of the first filament portion (132) and the second filament portion (134) is 4 mm or less, and wherein a diameter of a cross-section of each of the first filament portion (132) and the second filament portion (134) is 0.13 mm or less.

An electron microscope (100) is described. The electron microscope comprises an electron source (110) for generating an electron beam, a condenser lens (130) for collimating the electron beam downstream of the electron source, and an objective lens (140) for focusing the electron beam onto a specimen (16). The electron source comprises a cold field emitter with an emission tip (112), an extractor electrode (114) for extracting the electron beam (105) from the cold field emitter for propagation along an optical axis (A), the extractor electrode having a first opening (115) configured as a first beam limiting aperture, a first cleaning arrangement (121) for cleaning the emission tip (112) by heating the emission tip, and a second cleaning arrangement (122) for cleaning the extractor electrode (114) by heating the extractor electrode. Further described is a method of operating such an electron microscope.

Template-guided growth of carbon nanotubes using anodized aluminum oxide nanopore templates provides vertically aligned, untangled planarized arrays of multiwall carbon nanotubes with Ohmic back contacts. Growth by catalytic chemical vapor deposition results in multiwall carbon nanotubes with uniform diameters and crystalline quality, but varying lengths. The nanotube lengths can be trimmed to uniform heights above the template surface using ultrasonic cutting, for example. The carbon nanotube site density can be controlled by controlling the catalyst site density. Control of the carbon nanotube site density enables various applications. For example, the highest possible site density is preferred for thermal interface materials, whereas, for field emission, significantly lower site densities are preferable.

An emitter has a basic unit with at least one emission surface. Accordingly, the basic unit has deep structuring in a region of the at least one emission surface. More specifically, the basic unit has the deep structuring on both a front side and on a rear side in the region of the emission surface for improving emission properties.

There is provided a method for manufacturing a plurality of nanostructures comprising the steps of providing a plurality of spherical Zn structures and oxidizing the spherical structures in ambient atmosphere at a temperature in the range of 350° C. to 600° C. for a time period in the range of h to 172 h, such that ZnO nanowires protruding from the spherical structures are formed. There is also provided a field emission arrangement comprising a cathode having the aforementioned ZnO nanowire structures arranged thereon.

There is provided a method for manufacturing a plurality of nanostructures comprising the steps of providing a plurality of spherical Zn structures and oxidizing the spherical structures in ambient atmosphere at a temperature in the range of 350° C. to 600° C. for a time period in the range of h to 172 h, such that ZnO nanowires protruding from the spherical structures are formed. There is also provided a field emission arrangement comprising a cathode having the aforementioned ZnO nanowire structures arranged thereon.

In an embodiment, a method includes forming a first diamond layer on a substrate and inducing a layer of graphene from the first diamond layer by heating the substrate and the first diamond layer. The method includes forming a second diamond layer on top of the layer of graphene and applying a mask to the second diamond layer. The mask includes a shape of a cathode, an anode, and one or more grids. The method further includes forming a two-dimensional cold cathode, a two-dimensional anode, and one or more two-dimensional grids by reactive-ion electron-beam etching. Each of the two-dimensional cold cathode, the two-dimensional anode, and the one or more two-dimensional grids includes a portion of the first diamond layer, the graphene layer, and the second diamond layer such that the graphene layer is positioned between the first diamond layer and the second diamond layer.

A field emission device comprises one or more emitter elements, each having a high aspect ratio structure with a nanometer scaled cross section; and one or more segmented electrodes, each surrounding one of the one or more emitters. Each of the one or more segmented electrodes has multiple electrode plates. This abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

The present disclosure may provide a micro X-ray tube with a filter tube to filter X-rays and at the same time to serve as an insulator. For this, the X-ray tube may include a filter tube between a second electrode and a gate electrode, hence separating from each other. The second electrode may have a target and the gate electrode may accelerate an electron-beam to collide with the target. The filter tube includes an alumina (Al.sub.2O.sub.3). The target is inclined to allow the X-rays to be directed toward the filter tube.

An electron emission device includes a substrate and an electron emission layer. The electron emission layer is provided above the substrate, and is provided with an opening. The electron emission layer has an edge defining the opening and is configured to emit electrons from the edge when the edge is irradiated with light.