Electron emitters and methods of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.

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.

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.

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.

To stabilize an emitted electron beam, a thermoelectric field emission electron source includes: an electron source having a needle shape; a metal wire to which the electron source is fixed and configured to heat the electron source; a stem fixed to an insulator and configured to energize the metal wire; a first electrode having a first opening portion and arranged such that a tip of the electron source protrudes from the first opening portion; a second electrode having a second opening portion; and an insulating body configured to position the first electrode and the second electrode such that a central axis of the first opening portion and a central axis of the second opening portion coincide with each other, and to provide electrical insulation between the first and second electrodes, so as to provide a structure that reduces an amount of gas released when the first electrode is heated.

To stabilize an emitted electron beam, a thermoelectric field emission electron source includes: an electron source having a needle shape; a metal wire to which the electron source is fixed and configured to heat the electron source; a stem fixed to an insulator and configured to energize the metal wire; a first electrode having a first opening portion and arranged such that a tip of the electron source protrudes from the first opening portion; a second electrode having a second opening portion; and an insulating body configured to position the first electrode and the second electrode such that a central axis of the first opening portion and a central axis of the second opening portion coincide with each other, and to provide electrical insulation between the first and second electrodes, so as to provide a structure that reduces an amount of gas released when the first electrode is heated.

The present invention relates to an automatic sequence for repeatedly performing SEM observation and FIB processing by using a low acceleration voltage for a long time. In order to realize very accurate three-dimensional structure/composition analysis, in the automatic sequence for repeatedly performing sample observation using a scanning electron microscope using a CFE electron source and sample processing using a FIB device, low temperature flushing using the CFE electron source is performed at predetermined timing except for a SEM observation time. According to the present invention, the automatic sequence for repeatedly performing the sample observation using the scanning electron microscope using the CFE electron source and the sample processing using the FIB device can be performed for a long time. Therefore, it is possible to acquire a SEM image which achieves high resolution and improved current stability while the low acceleration voltage is used.

The present invention relates to an automatic sequence for repeatedly performing SEM observation and FIB processing by using a low acceleration voltage for a long time. In order to realize very accurate three-dimensional structure/composition analysis, in the automatic sequence for repeatedly performing sample observation using a scanning electron microscope using a CFE electron source and sample processing using a FIB device, low temperature flushing using the CFE electron source is performed at predetermined timing except for a SEM observation time. According to the present invention, the automatic sequence for repeatedly performing the sample observation using the scanning electron microscope using the CFE electron source and the sample processing using the FIB device can be performed for a long time. Therefore, it is possible to acquire a SEM image which achieves high resolution and improved current stability while the low acceleration voltage is used.

A system for performing surface analysis on a material, includes a pulsed electron source that forms a monochromatic beam of incident electrons; means for conveying the incident electrons to the surface of a sample of material, so as to form backscattered electrons, and the backscattered electrons to detecting means, the conveying means comprising at least one electron optical system; means for detecting the backscattered electrons; the pulsed electron source comprising: a source of atoms; a continuous-wave laser beam configured to form a laser excitation zone able to excite the atoms to Rydberg states; a pulsed electric field on either side of the laser excitation zone, the pulsed electric field being configured to ionize at least the excited atoms and to form a monochromatic beam of electrons.