An electron beam apparatus which can stably achieve high spatial resolution also during low acceleration observation using CeB.sub.6 for the CFE electron source is provided. In an electron beam apparatus having a CFE electron source, the emitter of the electron beam of the CFE electron source is Ce hexaboride or a hexaboride of a lanthanoid metal heavier than Ce, the hexaboride emits the electron beam from the {310} plane, and the number of the atoms of the lanthanoid metal on the {310} plane is larger than the number of boron molecules comprising six boron atoms on the {310} plane.

The present invention provides an emitter made of a hafnium carbide (HfC) single crystal that stably emits electrons with high efficiency, a method for manufacturing the emitter, and an electron gun and an electronic device using the emitter. An emitter according to an embodiment of the present invention is an emitter including a nanowire, in which the nanowire is made of the hafnium carbide (HfC) single crystal, at least an end of the nanowire through which electrons are to be emitted is coated with hafnium oxycarbide (HfC.sub.1-xO.sub.x: 0<x?0.5), and a field electron emission pattern of the end obtained by a field emission microscope (FEM) is a single spot.

An electron beam apparatus which can stably achieve high spatial resolution also during low acceleration observation using CeB.sub.6 for the CFE electron source is provided. In an electron beam apparatus having a CFE electron source, the emitter of the electron beam of the CFE electron source is Ce hexaboride or a hexaboride of a lanthanoid metal heavier than Ce, the hexaboride emits the electron beam from the {310} plane, and the number of the atoms of the lanthanoid metal on the {310} plane is larger than the number of boron molecules comprising six boron atoms on the {310} plane.

A method for producing a nanotip from a tip material provides a substrate which consists of the tip material or has the material in the form of a coating, produces a mask from a mask material selected so that, in a predefined reactive ion etching process, the mask material is removed at a lower etching rate than the tip material, and carries out the reactive ion etching process in an etching chamber. The mask material is additionally selected so that a gaseous component is released therefrom during the reactive ion etching process, the gaseous component not being released from the tip material. The method further comprises detecting the gaseous component while the ion etching process is being carried out, repeatedly determining whether an amount of the gaseous component in the etching chamber reaches a predefined lower threshold, and stopping the reactive ion etching process when the lower threshold is reached.

Optimization techniques are disclosed for producing sharp and stable tips/nanotips relying on liquid Taylor cones created from electrically conductive materials with high melting points. A wire substrate of such a material with a preform end in the shape of a regular or concave cone, is first melted with a focused laser beam. Under the influence of a high positive potential, a Taylor cone in a liquid/molten state is formed at that end. The cone is then quenched upon cessation of the laser power, thus freezing the Taylor cone. The tip of the frozen Taylor cone is reheated by the laser to allow its precise localized melting and shaping. Tips thus obtained yield desirable end-forms suitable as electron field emission sources for a variety of applications. In-situ regeneration of the tip is readily accomplished. These tips can also be employed as regenerable bright ion sources using field ionization/desorption of introduced chemical species.

Optimization techniques are disclosed for producing sharp and stable tips/nanotips relying on liquid Taylor cones created from electrically conductive materials with high melting points. A wire substrate of such a material with a preform end in the shape of a regular or concave cone, is first melted with a focused laser beam. Under the influence of a high positive potential, a Taylor cone in a liquid/molten state is formed at that end. The cone is then quenched upon cessation of the laser power, thus freezing the Taylor cone. The tip of the frozen Taylor cone is reheated by the laser to allow its precise localized melting and shaping. Tips thus obtained yield desirable end-forms suitable as electron field emission sources for a variety of applications. In-situ regeneration of the tip is readily accomplished. These tips can also be employed as regenerable bright ion sources using field ionization/desorption of introduced chemical species.